Myplace4u, une extension de la plate-forme eZoomBook (eZB), permet de minimiser la différence entre l'idéal et le réel. Le projet 'myplace4u' a été conçu pour la promotion de la littérature en reliant les textes aux lieux physiques ou imaginaire -lieux géographiques, historiques et touristiques. Le projet permet la construction d'une bibliothèque d'e-books multimédia comprenant plusieurs versions abrégées des oeuvres adossées aux versions originales. Une fonction de zoom permet aux lecteurs d'eZoomBooks sur la plate-forme de naviguer librement entre les versions abrégées et la version originale. Le but de cet article est de formuler l'hypothèse que l'outil eZB / myplace4u peut contribuer à atténuer le syndrome de désenchantement touristique grâce la manipulation de versions abrégées et enrichies d'oeuvres reliés à des lieux touristiques. La fonctionnalité distinctive de l'outil permet de « zoomer » sur des extraits littéraires et de les juxtaposer à des enrichissements multimédias. L'objectif n'est pas de réduire les attentes ni de décourager les touristes potentiels, mais plutôt de répondre aux difficultés provenant d'une perception biaisée du tourisme littéraire.

Mots-clés : Syndrome de Paris, « gestion des attentes du tourisme », myplace4u, tourisme littéraire, eZoomBook.

Abstract:

The Paris, Jerusalem, and Stendhal syndromes have drawn attention to the need for "tourism expectation management". When visiting places one has fantasized about, there may be significant differences between high expectations and everyday reality, a gap which may lead to severe culture shock and varying levels of physical and mental discomfort. myplace4u, an expansion of the eZoomBook (eZB) platform, provides a means to address this issue and minimize the difference between the ideal and the real. The 'myplace4u' project was designed for place branding and the promotion of literature by linking texts to places -geographical, historical, and touristic places visited physically or imaginatively. The project allows for the construction of a library of multimedia e-books in multiple abridged versions alongside the original version. A zooming function enables readers of the eZoomBooks on the platform to navigate freely between the abridged versions and the original version. The purpose of this article is to formulate the hypothesis that the eZB/myplace4u tool can help mitigate the syndrome of tourist disenchantment through its abridgement and enrichment features. The tool's capacity to 'zoom in' on extracts from literary works and to juxtapose these with multi-media enhancements fits well with the objective of expectation management in that the enhancement gives different but parallel perspectives. The goal is not to lower expectations nor to discourage future tourists, but rather to address the selective perception of literary tourism.

Keywords: Paris syndrome, "tourism expectation management", myplace4u, eZoomBook literary tourism.

MAKING SENSE OF A SITUATION

The purpose of this paper is to present the "myplace4u" collection of eZoomBooks for place branding and the promotion of literature. Myplace4u is a digital tool for literary tourism in that it makes it possible to link literary texts to places described within the texts. Besides adding value to both places and the literature in which they are described, the tool can be used as a means to structure the travel experience. This article in particular proposes a pedagogical approach to travel preparation. While the approach can be applied to any travel experience, the context used here is to apply the tool and literary content as a means to lessen the effects of negative travel experiences.

The eZoomBook methodology, of which the myplace4u is an application, is a userfriendly digital tool that allows contributors to customize the length of documents and provide the end-user (i.e., potential readers on the platform) the means to "zoom in" or "zoom out" of the original document. This gives users the option to read either the full version of a document (always present on the platform) or modified shorter versions that contributors create using the eZoomBook tool. The value added of the methodology lies in its capacity to adapt documents to readers' needs. Like a "zoom lens", the eZB methodology makes it possible to focus on or select the amount and type of content that is pertinent to a user all the while keeping the original unmodified document for reference and contextual perspective. In addition, the abridged versions (called "layers") can also be accompanied by enriched multi-media content. This makes pedagogical applications possible given that the choice, sequencing, and enhancement of content can be incorporated into the methodology.

THE MARKETING OF NOSTALGIA AND THE DESTINATION IMAGE OF PARIS

Tourism is a major income source for Paris as the city ranks among the world's most visited cities. According to the Paris tourist office, hotels in Greater Paris recorded 22.2 million arrivals in 2015. The office notes that despite a difficult context marked by the January and November 2015 terrorist attacks, the drop in visitors remained moderate at 1. 1% compared to 20141% compared to (press.parisinfo.com Nov 4, 2016)). Paris has a unique destination image (DI) that is connected to the romantic and nostalgic, to haute cuisine and fashion, to monuments and museums. The pull of nostalgia is a definite marketing advantage for the Paris brand. For many international tourists, Paris is an experience rather than a place. Moreover, internationally successful films tend to imprint on viewers this stereotyped and romantic version of Paris. Literature as well is a vehicle for transmitting a certain image of Paris. The 'lost generation' of American writers and expatriates who emigrated to Europe after World War I (Gertrude Stein, Ernest Hemingway, F. Scott Fitzgerald, T. S. Eliot) as well as the philosophers of the 60's (Sartre; Simone de Beauvoir, Camus, etc.) have left their impact and imprint on the American collective consciousness, especially among intellectuals. Even Parisian cemeteries have an attraction for tourists who make pilgrimages to pay their respects to Jim Morrison, Oscar Wilde, or Jean-Paul Sartre. [START_REF] Brown | Tourism and Pilgrimage: Paying Homage to Literary Heroes[END_REF], for example, sees a parallel between religious and literary pilgrims in that both feel the need to be close to those who have influenced their lives.

Nonetheless, while the widespread nostalgic destination image of Paris is a definite marketing advantage for the Paris brand, this image may come into conflict with the dayto-day contemporary reality of a very large modern cosmopolitan city of 2.24 million residents. For international tourists, the mismatch between the idealized and nostalgic Paris of the past and the Paris of the 21st century can be quite an anti-climax. In recent years, the generalist press (Kitching, Mail Online 2 May 2016; Sanchez, The Telegraph 28 March 2016; Lemaître, Le Monde March 30, 2010) has been highlighting a phenomenon called "the Paris syndrome" afflicting a number of visitors to Paris, and in particular, the Japanese. The syndrome is experienced by visitors whose expectations of the picture postcard Paris come up against some of the problems of everyday life: unwelcoming atmosphere, traffic, insecurity, noise, strikes, pollution, language difficulties, etc. As a result, a number of Japanese visitors have suffered physical symptoms of dizziness, confusion, and panic requiring repatriation, symptoms resembling in many ways those of culture shock. Researchers in intercultural management have long been familiar with the physical and psychological consequences of culture shock, the disorientation that arises when moving out of one's comfort zone into a foreign and unfamiliar environment, a condition that particularly afflicts expatriate managers and exchange students (for example, [START_REF] Sims Robert | Spring) 'An Examination of Salient Factors Affecting Expatriate Culture Shock[END_REF][START_REF] Friedman Perley-Ann | Expatriate Adjustment from the inside out: An Autoethnographic Account[END_REF]. Culture shock usually consists of different phases. Perhaps, the most concise and easy to remember description of these phases has been made by Dodd (1998): eager expectation; everything is beautiful; everything is awful; everything is ok. Unfortunately, for the Japanese tourist the time frame of a visit is too short to enter the "everything is ok" stage. Seeing a parallel between culture shock and the travel experience, Smith equates culture shock to anxiety: "culture shock is defined as a special kind of context specific anxiety, which typically accompanies intercultural communication encounters" (Dodd, 2008, p. 42).

POSSIBLE CAUSES OF THE PROBLEM AND SOLUTIONS

Given that the Paris syndrome seems to target Japanese tourists in particular, one explanation may be that the condition is culture-specific. The cultural model of G. Hofstede (1991) may explain why. He conducted an important empirical study (questionnaires given to 100,000 individuals in 40 countries) the statistical analysis of which uncovered four variables to explain cultural differences. These four dimensions, rated along a continuum of low to high, are as follows: power distance; masculinity/femininity; individualism/collectivism; uncertainty avoidance (1980). Hofstede statistically determined a coefficient for these dimensions for each country he studied to indicate the relative importance of the dimension at the national level. The model has been widely applied and tourism research has used the variables of Hofstede's model to define categories of tourist behavior (L. [START_REF] Manrai Lalita | Hofstede's Cultural Dimensions and Tourist Behaviors: A Review and Conceptual Framework[END_REF]. Of the four dimensions, uncertainty avoidance is a likely contributor to travel anxiety given that Hofstede correlates high UA and high anxiety levels and concludes that "…/… anxiety levels differ from one country to another. Some cultures are more anxious than others" (Hofstede, 1994, p. 115). According to Hofstede, UA is characterized by a need for predictability and planning. UA is experienced when members of a culture feel that they have little or no control of a present or future situation; they feel threatened by ambiguity and thus will often avoid unstructured situations. Using a scale ranging from 8 to 112 (low UA to high UA), Hofstede concluded that the Japanese culture is extremely averse to uncertain and ambiguous situations.

At 92, Japan is one of the most uncertainty avoiding countries on earth. […] You could say that in Japan anything you do is prescribed for maximum predictability. From cradle to grave, life is highly ritualized and you have a lot of ceremonies. For example, there is opening and closing ceremonies of every school year which are conducted almost exactly the same way everywhere in Japan. At weddings, funerals and other important social events, what people wear and how people should behave are prescribed in great detail in etiquette books. School teachers and public servants are reluctant to do things without precedence. In corporate Japan, a lot of time and effort is put into feasibility studies and all the risk factors must be worked out before any project can start. Managers ask for all the detailed facts and figures before taking any decision. This high need for Uncertainty Avoidance is one of the reasons why changes are so difficult to realize in Japan. (Hofstede, 2016) Frias et al. (2012), for example, conclude that UA cultures tend to seek highly structured situations when travelling and thus opt more frequently for the all-inclusive package tour. This is one effective way to employ an "avoidance strategy" and exclude from travel all that may be unplanned or spontaneous. If Hofstede is right in saying that anxiety can be culture-specific, then high UA cultures may need to have at their disposal coping strategies to overcome potential travel anxiety. [START_REF] Bitner Mary | Servicescapes: The Impact of Physical Surroundings on Customers and Employees[END_REF] speak of strategies of "approach and avoidance" when faced with situations where coping skills are called upon. They introduce an interesting concept that should be further investigated in tourism research: the notion of "travel competence". In their qualitative study, they look at how a consumer copes and co-creates an experience and how the tourist also deals with on-the spot incidents which trigger approach or avoidance strategies. Similarly, for Smith (2008, p. 41) "travel anxiety" and the consequent "fight or flight response" can be dealt with by treating it as any anxiety. His solution to the problem is a seven-point plan of systematic desensitization in line with research done on reducing the effects of anxiety in general. Steps one and two include positive visualization and relaxation techniques to reduce any unconscious fears about travel. Steps six and seven include development of support groups at home and feeling confident about one's abilities. Interestingly enough, steps three, four and five are all based on increasing pre-departure knowledge of the host destination as a means to reduce the distortion of the information gap between the perceived destination image and reality. These knowledge-based steps include practical tips on learning aspects of the language, culture, geography, infrastructure, etc. In other words, the more you know before you go (i.e., pre-departure preparation), the less travel anxiety there will be and the better you will cope with the unexpected. Being prepared with a reality check would seem to solve the problem and corresponds closely with the dictionary definition of expectation management: to seek to prevent disappointment by establishing in advance what can realistically be achieved or delivered by a project, undertaking, course of action, etc.

A PEDAGOGICAL APPROACH

There is a problem, however, in focusing only on pre-departure preparation. For some cultures the information gap between the native and target cultures may be very wide, as, say for the Japanese tourist in Europe. In addition, the pre-departure information needs to be reliable since skewed information will do more harm than good. Skewed information is certainly present in the popular romanticized DI of Paris. Moreover, the time phase for the processing of the experience should encompass not only 'before' but also 'during' and 'after'. What is needed then is a program spanning the pre-departure, the departure, and the post-departure stages allowing the visitor to modify as needed the perception of DI. An appropriate analogy comes from pedagogy and is that of "learning experience" in which learning objectives are defined at each stage of the process. While the term "learning objectives" may seem academic and scholarly for something as commonplace as tourism, it must be noted that a pedagogical approach to resolving the issue of culture shock may be an important insight into finding a solution for the Paris syndrome. Structuring the travel experiences as a learning experience would enable the future traveler to become aware of the stages of culture shock and the best way to cope. A structured pedagogical approach would allow tourists to "learn how to learn" from experiences and increase in this way their travel competence.

A pedagogical model to develop travel competence

One of the most widely-used models for structuring pedagogical activities is that of Benjamin [START_REF] Bloom Benjamin | Taxonomy of Educational Objectives; the Classification of Educational Goals[END_REF] later revised and expanded by Lorin Anderson, David [START_REF] Anderson Lorin | A Taxonomy for Learning, Teaching, and Assessing: A Revision of Bloom's Taxonomy of Educational Objectives[END_REF]. This taxonomy or classification of cognitive objectives has the form of a pyramid-like framework consisting of five levels of increasing difficulty. The premise of the taxonomy is that the lower more concrete levels (1, 2, 3) are stages in progression towards the top levels of higher complexity (4, 5, 6) of the pyramid. The 1956 taxonomy proposed six levels of increasing difficulty (the higher levels implying mastery of the lower levels): 1. Knowledge: memory or recall of information (names, places, dates, etc.) 2. Comprehension: understanding of information; explaining and summarizing; determining implications and consequences 3. Application: solving problems using knowledge and understanding 4. Analysis: pattern recognition; seeing hidden meaning and structure; ordering and classifying; breaking an entity down and seeing how the parts relate to the whole 5. Synthesis: using known information to create new ideas; generalizing; drawing conclusions or deductions 6. Evaluation: judging the pertinence of evidence; judging pertinence of a method.

With this model in mind, the myplace4u tool can structure the learning objectives for each phase of any travel experience: Pre-departure (knowledge + comprehension); Departure (application + analysis); Post-departure (synthesis + evaluation).

This pedagogical solution incorporates the original literary vocation of the myplace4u tool with that of expectation management. In other words, literature provides the context to explore discrepancies that may exist between a skewed idealistic destination image and what can be reasonably expected from a travel experience. The specific development of enriched eZB layers (photos; video; sound) on the myplace4u platform place aspects of a stereotypical DI and those of the real-life city in perspective. In addition, when placing actual physical surroundings in the context of works of literature, travelers have an added opportunity to rediscover a literary heritage.

The goal of eZBs is to offer the reader enriched short texts, material that can be read in an edited and abridged format. To understand how the zooming and abridgement functions work and how these are of value to the tourist, let us clarify the connection between eZB and myplace4u.

MYPLACE4U

The original purpose in creating the "myplace4u" collection of eZoomBooks was both for place branding and the promotion of literature by linking texts to placesgeographical, historical and touristic sites that can be visited physically or imaginatively. Indeed, these sites can be appreciated in relation to great works of literature -and vice versa. Besides adding value to both places and the literature in which they are described, the tool can be used as a means to structure the travel experience providing framework to better understand and cope with the unknowns of travel. At the heart of the eZB project is a blended-learning pedagogy for the promotion of reading through the structuring and development of "multi-scale" documentation: the eZB platform makes it possible to create interactive documents leading to the creation of multiple abridged versions of a given document through a Wiki-like system of construction. The eZB platform includes the following features: -a range of functionalities enabling users to create enriched documents, select quotes, write up summary lines to connect the quotes, and produce a multiple-scale documents; -an "elegant" Facebook-like organization for the forming of working groups; -a user-friendly publishing and distribution system; -a range of collaborative tools (for the sharing of documents); -multiple connections to given databases (private and public resources).

Currently under development, myplace4u is an added-on application to the eZoomBook tool. Since the template has been developed and is now available in opensource format, our team has been working on building a myplace4u library of eZBs opening up perspectives for the development of "place branding", "literary tourism" or "cultural tourism".

This collection, presently placed on our research blog (ezbresearch.hypotheses.org), can be uploaded to any website or platform that our potential partners wish to enrich. Readers on these sites and platforms will then have access to a corpus of enriched texts offering them a playful exploration of places to travel to and visit. The enrichments of the myplace4u eZoomBooks are accessible through a thematic tabulation system and include multimedia enrichments such as images, sound effects, and videos of places and include both fictional and non-fictional representations.

To understand how the myplace4u application adds value to the travel experience, we will now focus on one example in relation to Paris. Given the inherent pedagogical orientation of the eZB methodology, we will show how myplace4u uses the approach of Benjamin [START_REF] Bloom Benjamin | Taxonomy of Educational Objectives; the Classification of Educational Goals[END_REF] to structure and manage tourist expectations.

MYPLACE4U EZOOMBOOKS AND TEXTS ON PARIS

It is difficult to know where to start when creating a myplace4u eZoomBook for Paris, a city that has been the subject of numerous novels, short stories, travel memoirs. While our main emphasis will be on texts, other forms of art may play an equally important role. Paris is the city that has inspired not only writers, but other artists such as musicians, filmmakers, photographers and painters. Paris boasts an impressive literary and artistic heritage, having been home to great artists both past and present. This rich cultural heritage is indeed one of the attractions of the city.

Many websites from Lonely Planet to book review sites or travel blogs offer an artistic guide to Paris, mapping out places which will allow tourists to follow in the footsteps of famous artists. For example, one such site, girlsguidetoparis.com, lists the cafés and hotels that were home to the "literary and artistic elite", and displays pictures followed by captions or short texts highlighting the link between the café or hotel and several famous writers. For example, the café "Les Deux Magots" is presented through the prism of the Paris of the 20's and 50's.

Perhaps the most infamous hangout of Paris's literary and artistic elite, Les Deux Magots boasts the arty bohemia of Saint-Germain-des-Prés as its home. Opened in 1912, Les Deux Magots became a debauched rendezvous for the likes of Hemingway, Picasso and Breton in the 1920s, and Sartre, Camus and de Beauvoir in the 1950s. Envelop yourself in its charm and capture the magic of the great writers of the past by sitting in a window seat, nursing a coffee and letting those creative thoughts flow freely. (Sampson, 2016) This excerpt is a good illustration of how tourists may come to see Paris through the nostalgia for a golden era in the past. The guide includes the famous cafés and hotels such as Les Deux Magots, La Closerie des Lilas, Le Café de Flore, l'Autre Café, l'Hôtel Pont Royal, Apostrophe Hotel, etc. As a possible starting point for the creation of a myplace4u eZoomBook, online resources that link places and texts are available freely.

Initiatives such as Feedbook's "Paris Littéraire" or "Zola's Paris" or the "ville et roman" (city and novel) page on hypothese.org map out places to be found in literary texts and offer an inspiring thematic unity. There are also many commercial guides and applications which offer routes that you can follow on your smartphone linked to various enrichments. There are, however, three main differences between these commercial projects and our application. First, the philosophy behind the myplace4u eZoomBook collection is that the eZBs are crowdsourced and available for free on the Internet. The second difference between the commercial projects and ours is that the myplace4u eZoomBook contains a zooming in and out function which allows for a wide range of complex enrichments and a greater freedom for the user/reader of the myplace4u eZoomBook to navigate between the different levels. The third difference lies in the pedagogical project of travel preparation as a means to manage expectations.

Because the eZB tool allows for sensory enhancements of a given document, visual and audio resources can be uploaded and connected to appropriate sections of the text. The contributor can create tabulations to focus on specific interests or needs: -Itinerary or tracing the route (e.g., via Google) -Photo album -Then & now contrast -Text with read out quotes: comments to the landscape, re-enactment of the dialogue -Funny lines or comments -Poetic dimension (lyricism, description) -Opinions: observer perspective -Historical facts -Sound effects to give local color (for example, street noise, nature, etc.) -Music and lyrics -Movie excerpts (film adaptations).

The above list of tabulations is only an example. Each contributor can customize his/her tabulations according to the multi-layered reading objective he/she has in mind.

To illustrate the potential uses of the myplace4u tool and the pedagogies that can be developed, we have chosen the short story "Babylon Revisited" by F. Scott Fitzgerald, one of the most famous American expatriates of the lost generation. "Babylon Revisited" is not a travel book. It is, however, an appropriate choice to serve as an example of the methodology for the following reasons:

-Fitzgerald is widely regarded as one of the major writers of the 20th century and his literary legacy is part of a world cultural heritage. -The notion of remembering, seeing with new eyes, or "revisiting" a place are important themes in tourism.

-The novel contains a number of iconic sites of Paris described through the eyes of an expatriate.

-The film adaptation helps to compare and contrast the Paris of Fitzgerald's story and the Paris of today. -The story places special emphasis on Paris, as revealed by the title of the cinematographic adaptation: "The last time I saw Paris".

The tabulations we created not only provide links to the iconic sites in Paris, but they also offer readers a multi-layered version of the story, including an abridged form of the story that is linked to the original version.

The screenshot of our eZB (figure 1), shows the following 5 tabulations: Full text, Abridged Version, Enrichments, Locations, Texte en Français. The full text version is always present and gives the reader the opportunity to navigate between the full and the abridged version.

The screenshot below shows how color-coding is used to highlight the quotes and the summary phrases in the abridged version of the story. If a reader chooses to go from the abridged version to the full text (or vice versa), he/she simply needs to click on the sentence he/she is interested in.

When compared to the full version of the story, the abridged version is indeed more colorful because it is made up of a succession of quotes and summary lines, and thus much shorter and easier to read. The abridged version will be helpful to a reader interested in place since it will be easier to locate in the text what happens in the places highlighted in the "locations" tabulation.

The enrichments tab offers many enrichments ranging from reading excerpts to YouTube links to movie excerpts. More examples of enrichments will be given in the last part of this article. The locations tab traces the main character's itinerary through Paris mapping out the places Charlie Wales revisits: the Ritz, Montmartre, the Rue Pigalle, the Place Blanche, etc. and connecting these places to the protagonist's comments and observations. This tabulation could be further enriched by a photo album of these places and possibly include a "then & now contrast" -pictures and descriptions of both the Paris of the 1920s and now. The "texte en français" tab includes a translation of the work, showing the possibility to juxtapose several language versions of a document. While our eZB includes a French version of "Babylon Revisited", other versions are available in other languages, for example in Spanish: "Regreso a Babilonia". These versions could also be included in an eZB targeted at Spanish-speaking readers. At this stage, our team of researchers has not included Japanese or Chinese translations but it is, of course, possible to include any text in the public domain, and the system is open to receiving the contributions of other researchers or myplace4u/eZoombook creators who are knowledgeable in these languages.

These five tabs only illustrate what can be done and other tabs can be added depending on the specificities of the work and/or place in question (for example, a vocabulary tab for either difficult vocabulary or jargon; the enrichment tab can be replaced by several different tabs: music enrichment, film enrichments, etc.).

Given that the original vocation of the eZB tool was pedagogical, these tabulations also offer the possibility to structure the content of the myplace4u application in terms of learning objectives. For example, reading "Babylon Revisited" in an eZB format gives the reader/tourist an opportunity to cover all six educational objectives of Bloom's taxonomy in a time frame covering the entire experience -from preparing the trip to returning home.

The three steps are detailed below according to what the reader needs to do before, during, and after the visit. Each phase corresponds to a learning level as defined by Bloom.

Step 1: Pre-departure= "knowledge + comprehension"

The tourist needs to download the template from our website, understand the eZB structure and prepare to enrich the basic eZB he chooses from the collection. He may decide to create his eZB from scratch by using some of the textual recommendations in the resources previously quoted in our article. Once the text and the format of the eZB have been chosen, the tourist needs to plan his route, prepare his observation sections, make checklists, etc. It is possible for the eZB/myplace4u creator to include diary writing: he can either replace the original text(s) by his personal diary or add an extra tab entitled "journal" or "diary" or "personal comments" which he will then enrich throughout the pre-during-post phases.

Diary writing has been shown to be an excellent means to monitor the temporal dynamics of "in-person" change. In their article outlining the state of the art in diary methods, Bolger, Davis, Rafeli (2003, p. 580) indicate that a benefit of diary writing is that of "minimizing the amount of time elapsed between an experience and the account of this experience". They outline three important questions that diary writing can address:

-What is the typical person like, and how much do people differ from each other? -How does a typical person change over time, and how do people differ in change over time? -What is the within-person process for the typical person, and how do people differ in these processes? If a traveler starts a diary before setting off, he can then later contrast impressions with the pre-conceived ideas of the place to determine personal change over time. In addition, travelers can compare each other's experiences as a therapeutic process of learning about oneself in relation to others. It is important to know that one is not alone when undergoing the culture shock of travel or that others have had the same life-changing experiences that can arise from foreign travel.

As the myplace4u is an electronic diary, sharing diaries can eventually be an excellent means for a pre-departure overview of what to expect and what to look forward to. Of course, reading the diaries is only one part of the pre-departure phase since they may be biased and will have to be placed next to the objective information in the knowledge and comprehension phase.

This idea of sharing diaries can be extended to a project of a collaborative diary in the context of a group wishing to co-write about their experience, for example, groups of High School or university students travelling together. This implies the use of a collaborative document for the co-writing such as google drive. Once the co-writing has been achieved, the group coordinator can inject the co-written text into the eZB template. If the template is placed into a shared document system (such as dropbox), the contributors can take turns to write directly into the shared eZB.

Step 2: on site = "application + analysis"

When the tourist has reached his destination, he can collect the material that is relevant to his eZB. He will thus contrast and analyze differences between what he imagined and what is real and then he will correct the mismatch between the ideal and the real. He may decide to add elements that he had not foreseen before departure -such as local stories, recording conversations or short interviews. This may lead him to modify the tabulation articulation, which is easy enough to do when working with eZB templates. Indeed, the articulation is entirely left to the creator of the eZB. Because all eZBs are to be created under a Creative Commons license, future creators of eZB can build on existing eZBs to further enrich them. The example given in the screenshots of this article (with its the five-tabulation articulation) can serve as a template for other eZBs or as a starting point to create more tabulations for the exploration of the places in the texts.

Step 3: Post-departure= synthesis and evaluation This last step allows the tourist to work through any cognitive dissonance by synthesizing, polishing-up, proof-reading, and reflecting upon the experience, and then, finally, posting the finished eZB on a blog or platform. In the same way users of Instagram or YouTube like to post their pictures and videos, eZoombooks can be posted on any of the peer-sharing platforms which allow the users to upload an epub document. Sharing a finalized eZB brings something home to the tourist -something about the completeness of the experience, which is different to the one he first expected but which is perhaps all the more meaningful. As previously mentioned, extra tabs with links and enrichments can be added to this eZB. For example, tabs can be added in relation to:

the movie, with links from specific passages of the story to specific scenes in the movie, serving to highlight differences and similarities between the two version, but also showing the specific places which the text refers to; -academic enrichments: for example, "Babylon Revisited, a Lecture by Professor Bryant Mangum Virginia Commonwealth University" (1994), as well as student enrichments; -information on the author, including a Fitzgerald chronology; -a historical facts tab.

Other video material can include documentary excerpts, read-out quotes, comments (on the text, places or landscape) and re-enactments of the main character's thoughts. Sound effects could be included giving local color to the places mentioned in Fitzgerald's short story. Music and songs can also serve to highlight the atmosphere of the time and place, such as the music played in Parisian clubs in the 1920s. These elements which all contribute to an ideal image of Paris can also be compared with the surrounding noises of Paris today and music played in these same places where the clubs once stood or perhaps still stand. The Parisian atmosphere of today can thus be experienced by the reader/tourist via eZB prior departure or on site. Finally, some of the places of the story could also be linked to the Feedbook map previously mentioned, thereby showing how these places in Paris have inspired many other authors apart from Fitzgerald and will continue to do so.

"Babylon Revisited" also gives us an opportunity to illustrate how the myplace4u tool may move from enhancing the experience and pleasure of a text to that of provoking a deeper understanding of the meaning. One such goal would be to highlight the contrast between places which have very different symbolic meanings such as the Ritz, the streets of Paris, and Honoria's home, for example. Indeed, many scenes in "Babylon Revisited" take place on the streets or in the bars of Paris. Comments to the contributor's interpretation can be added in this "Locations" tab, as well as links to scenes in the cinematographic adaptation of the short story or any other type of enriched material, as explained above. The textual quality of Fitzgerald's short story can also be given prominence by creating thematic comments in relation to the symbolic places of the story. For example, one could seek to highlight tragic lines or turning points in the textkey moments in the main protagonist's shift in perspective. This can be done by providing a layer with a selection of quotes or connections to multimedia material, such as readings or links to the LibriVox audiobook recordings. Looping back to places, these quotes can be linked to the list of locations.

CONCLUSION

This article was motivated by meta-research on the Paris Syndrome which highlighted the tourists' lack of preparation with the encounter of Paris and the resulting psychological trauma. Our premise was that the management of cultural expectation through eZB could offer a way to alleviate the negative experience. We have shown that tourism can be treated as a pedagogical activity in which the tourist is given a chance to explore and learn. The eZB myplace4u pedagogy has an incorporated 3-step approach whereby the tourist personalizes eZBs and includes material of his own.

While the example of the F. Scott Fitzgerald story shows how the creator of an eZB can work on textual material in relation to places in Paris, it is only one example of how the eZB tool can structure the travel experience. The tourist/reader who wishes to become the creator of an eZB myplace4u can choose his text from the previously mentioned selection of texts connected to Paris, or he can use his own library of digital texts, or possibly write his own text in the form of a travel memoir. The ultimate level of personalization is reached when the creator of the eZB moves beyond the reading of an existing eZB, and chooses to write an original enriched journal which includes comments on the places he travels to, as opposed to commenting on given texts. Thus, when the tourist uses the eZB myplace4u template to create an eZB travel diary, he covers all six educational objectives of Bloom's taxonomy from knowledge and comprehension to synthesis and evaluation. By preparing, synthesizing, and reflecting upon, and, possibly sharing/posting his trip, he is given a chance to learn from this experience and work through the tension between an idealized destination image and the reality of his travel destination. A collection of such eZBs will serve as models for others who wish to add their own personalized versions of eZBs to the library.

Framing a tourist experience within a pedagogical model helps counter the information bias and/or overload that causes travel anxiety in that it breaks down the experience and allows the tourist to process incoming sensory data in steps. This article has taken the position that a pedagogical approach using Bloom's taxonomy is the best way to lessen the symptoms of travel anxiety and the resulting culture shock. The Paris syndrome has been used to illustrate the potential devastating effects of the disappointment that may arise from skewed expectations of a travel destination. Certain cultures may be more susceptible than others. While the Paris syndrome may be an extreme example, any disappointment following a travel experience is a problem for tourism management in that travelers who are disappointed will not repeat their experience and will also discourage others from going to the destination. The example of our study shows that myplace4U could add value both to the tourist experience and promotes the appreciation of literature. Future perspectives of this research would include testing the tool in real situations, with future travelers. Because myplace4U places such an important emphasis on texts, the project would be of benefit not only to those in the tourist industry but also to literature lovers wishing text to be (re)discovered in connection with the places they speak of and which inhabit our collective imagination.

Figure 1 -

 1 Figure 1 -Color-coded abridged version of the story

Figure 2 -

 2 Figure 2 -Story linked to "locations" tabulation

Figure 3 -

 3 Figure 3 -Extra tabulations ('Enrichment' tabulations)

•

  CLAUDIO NOBILI ........................................................................................................ Exploring the gestural meta-brievity by means of the Italian Gestibolario entries analysis • CHRISTINE EVAIN & CHRIS DE MARCO ......................................................................From the ideal to the real: a pedagogical approach to managing tourist expectations with the 'myplace4u' tool • NINON MAILLARD ...................................................................................................... Enjeu de la forme, effet de la brièveté : le droit dans ses nouvelles expressions (live-tweet, fiction cinématographique et websérie judiciaire)

	FROM THE IDEAL TO THE REAL:
	A PEDAGOGICAL APPROACH TO MANAGING TOURIST EXPECTATIONS
	WITH THE 'MYPLACE4U'
	Christine Evain & Chris De Marco
	Centrale Nantes, Audencia Research, TourismLab

~

Résumé : Les syndromes de Paris, de Jérusalem, et de Stendhal ont attiré l'attention sur la nécessité d'une « gestion des attentes des touristes ». En effet, il y a parfois des différences considérables entre l'attente du touriste et la réalité qui s'impose, ce qui peut entraîner un choc culturel sévère et des niveaux variables d'inconfort physique et mental.


A Preprint

Nicolas Ragot
email: ragot@esigelec.fr

Redouane Khemmar
email: khemmar@esigelec.fr

Adithya Pokala
email: adithya.pokala@groupe-esigelec.org

Romain Rossi
email: rossi@esigelec.fr

Benoit Decoux
email: decoux@esigelec.fr

Jean-Yves Ertaud
email: ertaud@esigelec.fr

TRAJECTOGRAPHY ESTIMATION FOR A SMART POWERED WHEELCHAIR ORB-SLAM2 VS RTAB-MAP

Keywords: Visual SLAM, ORB-SLAM2, RTAB-Map

This work is part of the ADAPT project relating to the implementation of a trajectography functionality that aims to measure the path travelled by a patient during the clinical trials. This system (hardware and software) must be reliable, quickly integrable, low-cost and real-time. Therefore, our choices have been naturally made towards visual SLAM-based solutions coupled with an Intel real-sense consumer sensors. This paper is a comparison of two well-known visual SLAM algorithms in the scientific community, ORB-SLAM2 and RTAB-Map, evaluated in different path configurations. The added value of our work lies in the accurate estimation of the trajectories achieved through the use of a VICON motion capture system.

Introduction

Estimating the camera trajectory while simultaneously reconstructing the environment is a key and well-know problem in robotics and computer vision. This can be achieved by the use of different measuring means (LIDAR, RADAR) and algorithms (particle filter, extended Kalman filter, GraphSLAM). When cameras are used SLAM techniques are named as visual SLAM (vSLAM). vSLAM algorithms have been widely proposed in the field of computer vision, robotics. Taketomi & al. [START_REF] Taketomi | Visual SLAM algorithms: a survey from 2010 to 2016[END_REF] proposes an exhaustive survey of real-time vSLAM algorithms developed from 2010 to 2016. In this paper we compare two well-known vSLAM algorithms: ORB-SLAM2 proposed by Mur-Atal & al in 2017 [START_REF] Mur-Artal | Orb-slam2: An open-source slam system for monocular, stereo, and rgb-d cameras[END_REF] and RTAB-Map proposed by Labbé & al. in 2018[4]. This comparison fits within the framework of the ADAPT project ("Assistive Devices for empowering disAbled People through robotic Technologies") for which driving assistance functionalities are implemented on a standard powered wheelchair to ensure the patient a safely driving. One requirement is related to the estimation of the path carried out by the patient during the clinical trials so as to evaluate the driving capabilities or the effect of the driving assistances in relation with an ideal trajectory. Both algorithms have been evaluated for an Intel real-sense camera 435D mounted on top of the ESIGELEC's robotics wheelchair which runs a ROS platform. ORB-SLAM2 has been tested for a monocular, stereo and RGB-D camera, while RTAB-Map, has been evaluated for a monocular and RGB-D camera. Several experiments have been carried out in a controlled indoor environment at the ESIGELEC's Autonomous Navigation Laboratory. These experiments are supported by the use of the VICON motion capture system used as a ground-truth to validate our results [START_REF] Merriaux | A Study of Vicon System Positioning Performance[END_REF]. Different motion scenarios have been implemented to test and benchmark both vSLAM algorithms: straight-line, straight-line and back, circular path with loop closure. The paper is organized as follows: section 2 presents the ESIGELEC's robotics wheelchair. Section 3 gives an overview of ORB-SLAM2 and RTAB-Map. Section 4 illustrates preliminary results related to the benchmarking of both vSLAM algorithms. The last section 5 gives a conclusion and perspectives.

Robotics Wheelchair Architecture

The robotics electrical powered wheelchair from the ESIGELEC's lab is an Invacare, model Bora from which all the proprietary electronics has been removed and replaced by an embedded PC running a Linux Ubuntu 16.04 LTS distribution, a motor driver from Roboteq, Xbox joystick in place of the original one which can be connected to the wheelchair through a USB or Bluetooth connection. The wheelchair software is fully developed under the ROS robotics middleware. Figures 1a and1b show the device and a schematic of the integrated hardware. ORB-SLAM2 is a real-time SLAM library for monocular, stereo and RGB-D cameras that computes the camera trajectory and a sparse 3D reconstruction. It is able to detect loops and re-localize the camera in real time. The system works in real-time on standard CPUs in a wide variety of environments from small hand-held indoors sequences, to drones flying in industrial environments and cars driving around a city. The back-end based on bundle adjustment with monocular and stereo observations allows for accurate trajectory estimation with metric scale. The system includes a lightweight localization mode that leverages visual odometry tracks for unmapped regions and matches to map points that allow for zero-drift localization. The main functionalities of ORB-SLAM2 are: feature tracking, mapping, loop closure and localization.

RTAB-Map

RTAB-Map stands for Real Time Appearance Based Mapping. It is distributed as an open source library since 2013. RTAB-Map started as an appearance-based loop closure detection approach with memory management to deal with large-scale and long-term online operation. It then grew to implement Simultaneous Localization and Mapping on various robots and mobile platforms. RTAB-Map supports both visual and lidar SLAM, providing in one package a tool allowing users to implement and compare a variety of 3D and 2D solutions for a wide range of applications with different robots and sensors.

Results Analysis

The tests were carried out in indoor and outdoor scenarios.

Conclusion

In this paper, we have presented a comparison between to vSLAM algorithms for achieving a trajectography functionality for a smart powered wheelchair ; ORB-SLAM2 and RTAB-Map. They have been evaluated with the use of the Intel realsense D435 camera making stereovision and RGB-D acquisition modalities available. Works are still in progress and next we aim to better qualify both algorithms by comparing each pose estimation given by the vSLAM with the ones given by the VICON system. This step will require the calibration of the camera in the VICON frame.

Figure 1 :

 1 Figure 1: Overview of the ESIGELEC's robotics wheelchair

  The first have been conducted in the Autonomous Navigation Lab (LNA Lab) and the second in the car parking in front of the ESIGELEC building. The LNA Lab is equipped with a VICON motion capture system which was used as the ground truth to capture the wheelchair and the travelled distance. Different motion scenarios have been implemented: straight-line, straight-line and back, circular path with loop closure. The figures 2a and 2b show screenshots of the ORB-SLAM2 and RTABP-Map for different paths in an indoor environment.(a) first caption. (b) second caption.

Figure 2 :

 2 Figure 2: Screenshots of ORB-SLAM2 and RTAB-Map

Figure 3 :

 3 Figure 3: trajectory comparison between ORB-SLAM2 and VICON system

Table 1 :

 1 Distance comparison between VICON and ORB-SLAM2 stereo & RGB-D

	Scenario Ground truth ORB stereo ORB RGB-D
	Indoor 1	7.82	7.69	7.16
	Indoor 2	6.98	7.38	6.81
	Indoor 3	15.05	15.49	14.32
	Indoor 4	21.75	21.17	21.31
	Indoor 5	29.69	21.47	22.13
	Indoor 6	37.69	38.84	38.79
	Outdoor 1	28	28.85	19.27
	Outdoor 2	28	27.29	17.83
	Outdoor 3	56	56.63	37.25
	Outdoor 4	92	94.55	65.87
	Outdoor 5	92	95.8	66.97
	Outdoor 6	80	84.38	66.24
	Outdoor 7	80	81.9	63.36
	Outdoor 8	160	172.6	129.41
	Scenario Ground truth RTAB-Map RGB-D
	Indoor 1	6.48	7.69
	Indoor 2	24.5	11.83
	Indoor 3	23.26	31.31

Table 2 :

 2 Distance comparison between VICON and RTAB-Map RGB-D

Acknowledgment

This research is supported by ADAPT Project (cofinanced by the ERDF within the framework of the INTERREG VA France (Channel) England programme). Many thanks to the engineers of the Autonomous Navigation Laboratory of IRSEEM for their support with the VICON system.


Redouane Khemmar

Jean Yves Ertaud

Xavier Savatier

Face Detection & Recognition based on Fusion of Omnidirectional & PTZ Vision Sensors and Heteregenous Database

Keywords: face recognition, compressed sensing, nomad biometric authentication, eigenface recognition, omnidirectional sensor

Large field of view with high resolution has always been soughtafter for Mobile Robotic Authentication. So the Vision System proposed here is composed of a catadioptric sensor for full range monitoring and a Pan Tilt Zoom (PTZ) camera together forming an innovative sensor, able to detect and track any moving objects at a higher zoom level. In our application, the catadioptric sensor is calibrated and used to detect and track Regions Of Iinterest (ROIs) within its 360 degree Field Of View (FOV), especially face regions. Using a joint calibration strategy, the PTZ camera parameters are automatically adjusted by the system in order to detect and track the face ROI within a higher resolution and project the same in facespace for recognition via Eigenface algorithm. Face recognition is one important task in Nomad Biometric Authentication (NOBA 1 ) project. However, as many other face databases, it will easily produce the Small Sample Size (SSS) problem in some applications with NOBA data. Thus this journal uses the compressed sensing (CS) algorithm to solve the SSS problem in NOBA face database. Some experiments can prove the feasibility and validity of this solution. The whole development has been partially validated by application to the Face recognition using our own database NOBA.

INTRODUCTION

Ample amount of development has been released with multiplecamera sensor systems to meet the rapidly growing demands in monitoring mobile robot applications. One of the recent examples is NOBA system that considers the field of biometrics and mobile robotics which are currently dissociated despite being based on common technological foundations (perception, detection and classification). A unique examples is the use of an omnidirectional camera in combination with PTZ camera, referred to as a dual camera system (as shown in Fig. 1). Omnidirectional cameras are able to exploit a wide Field Of View (FOV) within its 360 degrees for full range monitoring. However, low and non-uniform resolution of these catadioptric sensors make close observations of particular targets, especially in biometric authentication applications difficult. PTZ cameras with high mobility and zoom ability, compensates the deficiencies of omnidirectional cameras. Based on a unified model projection introduced by Geyer [START_REF] Geyer | A unifying theory for central panoramic systems and practical implications[END_REF], the catadioptric sensor is calibrated, in order to generate correct perspective images. By using Viola and Jones algorithm [START_REF] Viola | Robust real-time object detection[END_REF] in the resulting images, the program detects the face ROI, and then applies the tracking algorithm based on a correlation approach. Then a joint calibration method is performed to localize the face ROI in order to generate a zoomed in face image with high resolution. Face recognition can be considered as a kind of computer research or application for automatically identifying one person from a digital image or a video frame from a video source. Popular recognition algorithms can be divided into two main approaches: 1) geometric, which look at distinguishing features; 2) photometric, which is a statistical approach that distills an image into values and comparing the values with templates to eliminate variances. In this research area, there are some famous algorithms have been applied, such as Principal Component Analysis (PCA), Linear Discriminate Analysis (LDA), Local Binary Patterns (LBP), and so on. A comparative study of several algorithms in face recognition is presented in this journal. Firstly, the extracted zoomed face is projected into face space for face recognition using Eigenface algorithm. Secondly, a particular attention has been given to a more robust approach for face recognition. Compressed sensing with small sample size problem (combined with other recognition algorithms) will be selected for face recognition and applied to heteregenous database. This journal is organized as follows. Section 2 describes System architecture and processing, modeling and the calibration of catadioptric sensor. Section 3 focuses on the proposed face detection and tracking algorithms. The fusion procedure of the omnidirectional and PTZ cameras is described in section 4. Section 5 describes about the implementation of Eigenface algorithm on our NOBA local database. In Section 6, we will use the CS algorithm to solve face recognition task in which we introduce our research background and related theory. Section 7 illustrates the experiment/analysis results and Section 8 concludes this journal.

SYSTEM ARCHITECTURE AND PROCESSING

In the presented work, we focus on the issues related to face detection, extraction and recognition in a two camera serial architecture. The developed system is characterized by unbalanced sensors functionalities : A data exchange program from the processing unit is designed to detect the domain of interest through the wide-field catadioptric sensor. The main program is performed to manage the processing and the pointing of the PTZ camera into the corresponding region of interest. Commanding and controlling position of the PTZ camera is established by using a network connection through http sockets (virtual channels), where messages and control information are sent and received.

The catadioptric Sensor

Fixed view point constraint. : The architecture of catadioptric sensor adheres to the Single-View-Point (SVP)theory [START_REF] Baker | A theory of single-viewpoint catadioptric image formation[END_REF]. The SVP constraint enables to generate correct perspective images. In fact, the optical center of the camera has to coincide with the second focus F of the hyperbola located at distance 2e from the mirror focus as illustrated in Fig. 2. The eccentricity "e" is a parameter of the mirror given by the manufacturer. To realize this task, we first calibrate our camera with a standard calibration tool to determine the central point and the focal length. Knowing the parameters of both the mirror and the camera, the image of the mirror on the im-Fig. 2. Image Formation with an hyperbolic mirror. age plane can be easily predicted if the SVP constraint is taken into consideration, as shown in Fig. 2. The expected mirror boundaries are superposed on the image and the mirror has then to be moved manually to fit this estimation as shown in Fig. 3.

Sensor calibration

Sensor calibration is the process to determine the optical and geometrical features which are generally addressed as intrinsic and extrinsic parameters and they allow to estimate the correspondence between the 3D points of the scene and their projection into the image plane (pixel coordinates). The camera calibration used is based on a generic model introduced by [START_REF] Geyer | A unifying theory for central panoramic systems and practical implications[END_REF] and [START_REF] Barreto | A unifying geometric representation for central projection systems[END_REF], and then, modified by [START_REF] Mei | Single view point omnidirectional camera calibration from planar grids[END_REF], who generalized the projection matrix and took into consideration distortions. Further calibration details can be found in [START_REF] Scaramuzza | A flexible technique for accurate omnidirectional camera calibration and structure from motion[END_REF] and [START_REF] Ramalingram | Towards complete generic camera calibration[END_REF]. Figure 5 represents the projection process. As described in [START_REF] Barreto | A unifying geometric representation for central projection systems[END_REF] and [START_REF] Mei | Single view point omnidirectional camera calibration from planar grids[END_REF] as well as mentioned in [START_REF] Iraqui | Fusion of omnidirectional and ptz cameras for face detection and tracking[END_REF], the projection of a 3D point can be done by projecting the 3D point X[w y z] onto the unit sphere centered on C m : then Points X s = [x s y s z s ] T are, then, projected onto the new frame with the origin C p = [0 0 ξ] T , the obtained point (X s ) Cp onto a normalized plane and finally the last step enables us to find the camera projection matrix K expressed according to γ u and γ v , which are respectively, the generalized horizontal and vertical focal length, and ( u 0 , v 0 ) the coordinates of the principal point on the image point and the skew α :

p = K.m = γ u γ u .α u 0 0 γ v v 0 0 0 1 .m (1)
In our model, we consider that the impact of the parameter α, often null, is irrelevant. Parameters to be estimated in that model are : ξ, γ u , γ v , u 0 and v 0 .

With the tool developed by [START_REF] Boutteau | Reconstruction tridimensionnelle de l´environnement d´un robot mobile a`partir d´informations de vision omnidirectionnelle pour la preparation[END_REF], calibration is achieved by observing a planar pattern at different positions. The pattern can be freely moved (the motion does not need to be known) and the user needs to select the four points corners pattern. This calibration process is similar to that of Mei [START_REF] Mei | Single view point omnidirectional camera calibration from planar grids[END_REF]. It consists of a minimization over all the model parameters of an error function between the estimated projections of the pattern corners and the measured projection using Levenberg-Marquardt algorithm [START_REF] Levenberg | A method for the solution of certain probless in least squares[END_REF]. This minimization process enables to find the parameters combination that reduces the error of pattern retro projection.

FACE DETECTION & TRACKING BASED ON MERGER OF CATADIOPTRIC SENSOR AND PTZ CAMERA

Most of image processing techniques are performed on conventional images, i.e. perspective images. Actually, deformations caused by the catadioptric system do not give us the opportunity to perform the existing face detection algorithms on raw images (Fig 4 .). As a consequence, geometrical transformations should be performed to obtain a panoramic image close to perspective images, where the face detection algorithm will be performed.

Panoramic images unwrapping

The existence of the model of the unit sphere, simplifies the unwrapping problem. Under the fixed view point constraint and by performing a retro projection, we are able to project the pixels of the panoramic pictures onto the unit sphere used in the unified model. Then, these pixels are projected onto the image plane. Thereby, we obtain the mapping between the pixels on the panoramic image and their corresponding on the camera retinal plane. Fig. 5 shows the result of the spherical transformation of the considered catadioptric image. Face detection algorithm is applied to these unwrapped images.

Face detection and tracking algorithms

Face detection techniques have been researched for years and much progress has been proposed in literature. However, in 2001, Paul Viola and Michael Jones [START_REF] Viola | Robust real-time object detection[END_REF] achieved a robust real time method for face detection, which was fifteen times quicker than the methods existing at that time. The technique relies on the use of simple Haar-like features that are evaluated quickly through the use of a new image representation called "integral image" that allows fast feature evaluation. Fig. 6 represents two of the 60000 Haar-like features available.

To select the best filtering feature, Adaboost, the machine learning introduced in [START_REF] Freund | A decision-theoritic generalization of on-line learning and an application to boosting[END_REF], is used. In fact, given a set of weak classifiers, not much better than random, if we iteratively combine their output, the training error will quickly converge to zero. shows the detected and zoomed face image. As explained in [START_REF] Iraqui | Fusion of omnidirectional and ptz cameras for face detection and tracking[END_REF], the face ROI so obtained is zoomed in with a high resolution which further can be processed for face recognition.

MERGER OF OMNIDIRECTIONAL AND PTZ CAMERAS 4.1 Joint Calibration Strategy

The joint calibration method is based on defining a reference position (x 0 , y 0 ) for the PTZ camera on the catadioptric 360 • image. This position has to coincide with the default orientation of the PTZ camera and is chosen as the starting point for pan angle evaluation (Fig. 7). In fact, given a point p(x, y) and the image catadioptric image center C(x 0 , y 0 ), we can compute the pan angle θ p in the

θ p = arctan y -y 0 x -x 0 (2) tan(α pan ) = v y v x (3)
The detailed explanation and formulae is inspired by paper [START_REF] Iraqui | Fusion of omnidirectional and ptz cameras for face detection and tracking[END_REF].

Face detection with PTZ camera

As explained in the previous sections, the catadioptric sensor is able to detect and track face ROIs. By using the ROI data localization from the catadioptric images, the PTZ camera can detect and also make a zoom in the face ROI. Brief descriptions of the different steps for the face ROI localization are as follow: Firstly, perform Viola and Jones face detection algorithm on the unwrapped catadioptric image to identify and localize the face ROI. Secondly, using the pan angle of the ROI center, calculate the pan angle to be directed to the PTZ camera. We use a constant tilt angle and a minimum zoom value. This enables us to point the PTZ camera on a large area where the face is probably located. Thirdly, perform again, Viola and Jones face detection algorithm to detect the face ROI in the obtained PTZ image. Finally, command the PTZ camera in order to center the face ROI detected in the PTZ image (pan and tilt calculation) and then apply the zoom factor computed according to both image and ROI widths and heights, as expressed below:

Zoom = M in Image width ROI width , Image height ROI height (4)
This last step enables us to obtain a zoomed in face image with high resolution, is useful for face recognition processing.

FACE RECOGNITION BASED ON FUSION OF CATADIOPTRIC AND PTZ VISION SENSORS

Face recognition is a very active area of research in computer vision and biometric fields since late 1980s. Among the plethora of techniques available Eigenfaces technique is one of the earliest appearance-based face recognition methods, which was developed by M. Turk and A. Pentland in [START_REF] Turk | Eigenfaces for recognition[END_REF]. The study and evaluation of the performances of this method for the Fusion based System may be interesting to implement in Real Time face recognition. In this section, we study the NOBA face recognition based Eigenface algorithm.

The Eigenface Algorithm

The eigenfaces technique for face recognition, developed by M. Turk and A. Pentland [START_REF] Turk | Eigenfaces for recognition[END_REF], consists of two main phases: • Learning: This phase utilizes the idea of the Principal Component Analysis (PCA) and decomposes face images into set of characteristic feature images called eigenfaces. • Recognition: This phase is then performed by projecting a new face into a low dimensional linear space defined by the generated eigenfaces in order to analyze and then to recognize it.

Learning phase. The learning phase for face recognition technique involves the following steps:

-The first step is to obtain a set S with M training face images. Let a face image be a two-dimensional N by N array of intensity values. After obtaining our set of face images, we calculate the mean images Ψ. -The next step consists in calculating the difference faces by subtracting the average face from each input image. -This set of very large vectors is then subject to the principal component analysis method, which seeks a set of M orthonormal vectors µ n , which best describes the distribution of the data. The k th vector µ k is chosen such that : We note that the vectors and scalars are the eigenvectors and eigenvalues, respectively, of the covariance matrix.

λ k = 1 M M n-1 (µ T k φ n ) 2 (5)
The covariance matrix C is defined as follows :

C = 1 M M n-1 Φ n Φ T n = AA T (6) With A=[Φ 1 Φ 2 Φ 3....... Φ M ]
Following this equation set, we construct the M by M matrix L = A T A , where L mn = Φ T m Φ n and find the M eigenvectors v n of L. These vectors determine linear combinations of the M training set face images to form the eigenfaces µ n :

µ n = M k=1 v nk Φ k = Av n , n = 1.......M (7)
With this method, the calculations are greatly reduced from the number of pixels in the images (N 2 ) to the other number of images in the training set (M). 5.1.2 Recognition Phase. The usefulness of the eigenvectors varies according to the associated eigenvalues. In fact, we choose only the most meaningful eigenvectors corresponding to the highest eigenvalues and we ignore the rest. As a consequence, the number of basis functions is reduced from M to M' (M' less than M) and the computation is reduced. The recognition procedure is summarized as follows:

(1) A new face, to be identified, is transformed to its eigenface components. First, we compare our input image with the mean image and then multiply their difference with each eigenvector of the obtained L matrix. Each value would represent a weight and would be saved on a vector Ω :

ω k = µ k (Γ -Φ) (8)
where

Ω T = [ω 1 , ω 2 , ω 3 ..........ω M ]
(2) We determine which face class provides the best description for the input image. This is done by minimizing the Euclidean distance and also the distance between the image and the face space :

ξ k = Ω -ΩK 2 ξ = Φ -Φ f 2 (9)
(3) We choose a threshold that defines the maximum allowable distance from any face class, and a threshold that defines the maximum allowable distance from face space. If the minimum distance and the distance , classify the input face as the individual associated with class vector. If the minimum distance but the image may be classified as unknown.

(4) If the new face is classified as known individual, this image may be added to the original set of familiar set images, and the eigenfaces may be recalculated. This gives the opportunity to modify the face space as the system encounters more instances of known faces.

The entire eigenface program is implemented in C language by using OpenCV library and the main functions developed to learn and recognize faces with OpenCV eigenface methods. 16 face images for each subject with 4 frontal images, 8 images for different tilts, 2 facial expressions images, 2 images with various illuminations. Image features are mentioned in Table 1. Our idea is to test and verify the results of Eigenface on our own database and see the efficiency and accuracy in terms of implementation.

Results obtained under the heterogeneous database

To test performances of the developed application, we used a free publicly available face database, the Olivetti Research Laboratories (ORL). This face database provides 10 sample images of each of 40 subjects. For some of the subjects, the images were taken at different times, varying lighting slightly, facial expressions (open/closed eyes, smiling/non-smiling) and facial details (glasses/no-glasses). All the images are taken against a dark homogeneous background and the subjects are in up-right, frontal position (with tolerance for some side movement). And we merged our subjects (under the same conditions) with this database to obtain a Heterogeneous database. The experimental results are performed with 12 subjects (10 ORL + 2 NOBA database) for the time being. Better results and testing to be done on extended number of subjects in the near future.

Various scenarios.

Results obtained show that the developed eigenface program recognizes correctly the considered people belonging already to the face database (training data). The index of the nearest face image corresponds to the ground truth and the confidence level is at 100%. The confidence level is calculated based on the Euclidean distance, so that similar images should give a confidence between 0.5 to 1.0, and very different images should give a confidence between 0.0 to 0.5. The confidence level has to be higher than 0.6 because face images of this person are included to the database but they are not acquired in the same conditions. Excluded images outside of the training database with a confidence level varying from 0.87 until 0.95. Sometimes, this level confidence can be higher until 0.99 and lower until 0.6. Although the testing images don't correspond to any person, the algorithm provides a confidence level very high (greater than 0.8) in both cases. With results obtained in this test and several tests performed, we conclude that the confidence level is not a good criterion on which we have to rely, in order to recognize people. The algorithm works only when the index of the nearest training face image corresponds exactly to the one of the testing one. The results for the test images (which are mentioned in Table 2 and 3) of two subjects which are trained but doesnot have the exact match. So confidence level is not 1.

Training Subjects s20 to s30 and two of NOBA database s45 & s50 are trained except s23/6,s23/7,s50/8,s50/9,s45/2,s50/2 & s26/1. The results obtained shows the difference in Confidence level depending on whether that face was present in the training data or not.

Better the match, higher the confidence level approaching 1.

Accuracy can be seen to be almost closing 100% as the trained data is able to recognize the test image if the subject is trained previously no matter image do not match exactly.

COMPRESSED SENSING FACE RECOGNITION METHOD IN HETEROGENEOUS DATABASE WITH SMALL SAMPLE SIZE PROBLEM

The traditional approach to accomplish one face recognition task is by comparing selected facial features from the image and a facial database. Actually, the fundamental of these methods is based on Euclidean distance. However, the recognition result of this idea may be not satisfactory in some situation. One common problem in many databases is so-called Small Sample Size (SSS) problem.

When the sample size is smaller than the sample dimensionality, the within-class scatter matrix is singular, which is also named the SSS problem. This section of paper aims to study the performance of Compressed Sensing (CS) algorithm for face recognition task in NOBA database. There will be SSS problem in some special situation.

Background and Theory

6.1.1 NOBA Face database. During the construction of NOBA database, the acquisition conditions are verified like variations of poses of head and eyes direction and illuminations conditions. However, as many other face databases (where the images are medium quality even worse), there will be SSS problem in NOBA when the training samples can not be acquired adequately. Thus we need to use some new methods to improve this situation.

6.1.2 What is compressed sensing?. As a novel signal processing method, CS has been a hot point topic in many research fields. The fundamental theory of CS has been respectively proved by Candès, Tao and Remberg [START_REF] Baker | A theory of single-viewpoint catadioptric image formation[END_REF][START_REF] Barreto | A unifying geometric representation for central projection systems[END_REF], and Donoho [START_REF] Boutteau | Reconstruction tridimensionnelle de l´environnement d´un robot mobile a`partir d´informations de vision omnidirectionnelle pour la preparation[END_REF]. On the contrary of traditional signal processing, this method means that the signal can be recovered from much fewer measurements than what is usually considered necessary. From the research of Candès et al. [START_REF] Baker | A theory of single-viewpoint catadioptric image formation[END_REF][START_REF] Barreto | A unifying geometric representation for central projection systems[END_REF], one CS framework can be composed of two main parts. The first part is CS sampling process which is that the original signal x ∈ R N can be acquired through the following linear random projections as :

y = Φx = {< x, ϕ i >} | M i=1 x ∈ R M with x ∈ R N ( 10
)
where Φ is an underdetermined sensing matrix, M N , and y is the so-called sensing data of x. The second part is CS recovery process which is essentially an improvement of pseudoinverse operation. Although Φ and y can be acquired after CS sampling, Φ is underdetermined which is difficult to find the inverse. In fact, if x is sparse (K M ) and the RIP (Restricted Isometry Property) of Φ is fulfilled, the inverse problem of Eq.( 10) can be transformed as :

min x 0 s.t. Φx = y (11)
In theory, the solution of Eq.( 11) can be global optimal. But the l 0 -norm induces a complete metric topology for the space of measureable functions. And the l 0 -norm minimization belongs to NP (Non-deterministic Polynomial) problem which is hard to solve.

min x 1 s.t. Φx = y (12)
Fortunately, Candès, Tao and Romberg [START_REF] Baker | A theory of single-viewpoint catadioptric image formation[END_REF][START_REF] Barreto | A unifying geometric representation for central projection systems[END_REF] give and prove the critical point of CS that the optimal solution in l 1 -norm minimization of Eq.( 12) can be equivalent to in l 0 -norm minimization of Eq.( 11) under some conditions. This will guarantee the feasibility and stability of CS recovery problem.

CS in Face Recognition

In the domain of Face Recognition (FR), some new methods based on CS have been presented. There are two typical FR approach with CS. One is Sparsity Preserving Projections (SPP) [START_REF] Scaramuzza | A flexible technique for accurate omnidirectional camera calibration and structure from motion[END_REF]. Unlike many existing techniques such as Local Preserving Projection (LPP) and Neighborhood Preserving Embedding (NPE), where local neighborhood information is preserved during the Dimensionality Reduction (DR) procedure, SPP aims to preserve the sparse reconstructive relationship of the data, which is achieved by minimizing a l 1 regularization-related objective function. The obtained projections are invariant to rotations, rescalings and translations of the data, and more importantly, they contain natural discriminating information even if no class labels are provided. Moreover, SPP chooses its neighborhood automatically and hence can be more conveniently used in practice compared to LPP and NPE. Another is the famous Sparse Representation (SP) [START_REF] Freund | A decision-theoritic generalization of on-line learning and an application to boosting[END_REF]. Based on a SP computed by l1-minimization, a general classification algorithm is proposed for (image-based) object recognition. With sparsity properly harnessed, the choice of features becomes less important than the number of features used. Moreover, occlusion and corruption can be handled uniformly and robustly within the same classification framework. One can achieve striking recognition performance for severely occluded or corrupted images by a simple algorithm with no special engineering. Recent development in the emerging theory of SP or CS [START_REF] Freund | A decision-theoritic generalization of on-line learning and an application to boosting[END_REF] reveals that if the solution x 0 sought is sparse enough, the following problem can be solved in polynomial time by standard linear programming methods :

min x 1 s.t. Φx = y
Even more efficient methods are available when the solution is known to be very sparse. For each class i, let δ i : R N → R N be the characteristic function which selects the coefficients associated with the i-th class. For x ∈ R N , δ i (x) ∈ R N is a new vector whose only nonzero entries are the entries in x that are associated with class i. Using only the coefficients associated with the i -th class, one can approximate the given test sample y as ŷi = Aδ i ( x1 ) . We then classify y based on these approximations by assigning it to the object class that minimizes the residual between y and ŷi :

Identity(y) i=1,...,k = min y -Aδ i ( x1 ) 2 (13)
6.3 Experiments and Analysis 6.3.1 Experiment context. Fig. 10 shows the flowchart of two face recognition methods LBP and CS. In fact, the function of LBP can be considered as a kind of feature extraction method; and CS is not the feature extraction technique but a special classification strategy which is based on CS theory. Therefore, the goal of this experiment is to actualize the contrastive experiment of traditional method (LBP) and CS method in some face image dataset with SSS problem.

CS under heterogeneous face database.

In this experiment, some face images will be selected from several different databases as the experimental samples to compose a heterogeneous face database, including NOBA, ORL and CSU as it shown in Fig. 11.

There are ten different images of each of 31 distinct subjects. For some subjects, the images were taken at different times, varying the lighting, facial expressions and facial details, etc. The size of each image is 92x112 pixels, with 256 grey levels per pixel. Generally, there are at least two pivotal steps in any pattern recognition process. One is feature extraction and another is classification technique. In this experiment, Local Binary Patterns (LBP) and Sub-Sampling (SS) will be used as two feature extraction methods; and Nearest Neighbor (NN) and CS will be selected as two classification methods. Therefore, this experiment consists of three combinations which are 1) LBP-NN, 2) SS-CS and 3) LBP-CS.

For this heterogeneous database, two strategies about how to select test sample will be actualized. Firstly, is to select one image as test sample randomly form the whole database. In other words, the test sample may be from NOBA, ORL or CSU. Secondly, is that only NOBA image will be chose as test sample. No matter which strategies, three combinations about face recognition will be carried into execution. And recognition rate is the final index to evaluate the performance of different three recognition methods. The code of LBP is cited from the work of Ahonen et al. [START_REF] Geyer | A unifying theory for central panoramic systems and practical implications[END_REF]. The code of CS is referred from the research work of Koh et al. [START_REF] Iraqui | Fusion of omnidirectional and ptz cameras for face detection and tracking[END_REF]. In each group, there are 10 time iteration operation with three recognition strategies (LBP-NN, SS-CS and LBP-CS). And the number of realization is 100 in each iteration operation. 1) Fig. 12 (a) shows the result when the test sample is selected from the whole heterogeneous database randomly. Obviously, the recognition rate of SS-CS is much better than LBP-NN and LBP-CS. The difference between SS and LBP is that the former is redundancy but the latter is not. It implies that the redundancy feature extraction method (such as SS) will more suit to SP face recognition. 2) Fig. 12 (b) shows the result when only NOBA images can be randomly selected as the test sample. In this group, it shows that both LBP-NN and SS-CS are good enough for face recognition task. However, the result of LBP-CS is not satisfactory which is only about 0.7. This indicates that LBP can be good at the traditional recognition or classification problem but it may not work well in the CS method. 6.3.3 CS under NOBA face database. This experiment aims to study the performance of CS algorithm for face recognition task with SSS problem in NOBA database. There are two classification standards which one is by behavior and another is by subject. Fig. 13 shows the two classification examples. As same as the last experiment, three recognition combinations will be selected, including 1) LBP-NN, 2) SS-CS and 3) LBP-CS. However, only one strategy about the selection of test sample will be actualized. It is that the test sample number will be generated randomly in each system running. As the above mentioned, there are two classification standards for NOBA database. For the one standard with behavior, the number of each class N 1 is only 2. For another standard with subject, the number of each class N 2 is 15. In NOBA database, the size of each image S is 92x112 pixels. Because of x ∈ R N , it is obviously that there is the so-called SSS problem in NOBA. Actually, the SSS problem is known to have significant influences on the design and performance of a statistical pattern recognition system. In other words, the execution of traditional recognition method (such as LBP-NN) may encounter computational difficulty. Therefore, the purpose of this experiment is not only to compare the recognition rate based on LBP or CS in NOBA but also to research the performance of the two different recognition methods in the SSS problem.

7. RESULTS

Face Recognition based Eigenface Algorithm Results

The preliminary results of the actual implementation of the initial prototype of the system is discussed in this section. In order to test the proposed system, the omnidirectional camera has been placed at 20 cm under the dome Axis PTZ camera [START_REF] Iraqui | Fusion of omnidirectional and ptz cameras for face detection and tracking[END_REF]. Viola Jones [START_REF] Viola | Robust real-time object detection[END_REF] algorithm can detect only frontal and semi-profile faces.Once the face ROI localization is determined from the unwrapped image, the program sends the corresponding pan angle via http sockets. Then, a separated process is created to detect the face in the current PTZ image (Fig. 7a) by applying Viola and Jones algorithm. Fig. 7(a) illustrates the resulting image after performing this face detection algorithm. Finally, the program control automatically the camera in order to center and zoom in the detected face localization. As a consequence, we obtain a high resolution face picture (Fig. 7 b).

The localized PTZ image is then downsampled and converted to grayscale image of 92x112 (low-dimensional linear subspace defined by eigenfaces) and saved into the test database for recognition and eigenface algorithm is implemented to check for the authenticity or match of the given subject with that of the training or registered database or subject. A new face is compared to known face classes by computing the distance between their projections onto the face subspace. Test results obtained (as shown in Fig. 9) demonstrates that the algorithm provides good results when the testing images correspond to known people belonging to the training face database. Further one system limitation is represented by the poor resolution in the unwrapped images (Fig. 8). This can affect performances of the face detection algorithm. Actually, at relatively high distances from the optical axis of the omnidirectional camera (more than 2 meters), Viola and Jones detector is not able to detect face location in these unwrapped images. We can notice that the Viola and Jones algorithm performs more efficiently when the target face is closer to the catadioptric sensor and also when assuming adequate illumination conditions. The current system is also limited by the large number of threads, the program runs. This affects the processing time of the application and the frame rate of the video stream. Therefore, to further optimize these parameters, improvements in the system architecture and improvements related to the decision criteria should be implemented during the last phase of recognition are objectives of the upcoming studies.

Face Recognition based Compressed Sensing with SSS Problem Results

LBP-NN, SS-CS and LBP-CS still are used as the recognition strategy for NOBA database. As two main parameters, the system of each strategy will have 10 iterations respectively and each iteration will has 100 realizations. Although the level of SSS problem is subdued, it still has a negative influence to the recognition method with LBP (LBP-NN and LBP-CS). Because SS can reserve redundancy information which is the pivotal factor in CS method. This means that SS-CS may be one useful solution to SSS problem in face recognition.

CONCLUSION

Firstly, in the first part of this paper, we proposed a unique vision system, effecient to automatically detect and track ROI at a higher zoom level. Experimental results using robust calibration methods and real-time detection and tracking algorithms demonstrates a significantly improved accuracy in providing a closer look of the target for recognition purposes. A panoramic FOV eliminates the need for more cameras or mechanically turnable camera. The integration of authentication processes like face detction, tracking and recognition makes the system self sustained for biometric authentication.The advantages of omnidirectional sensing are obvious for application like survelliance and immersive telepresence.

Secondly, according to the experimental result, it can be seen that CS face recognition method (SS-CS) usually can be better than the traditional method (LBP-NN) which is based on Euclid distance. And the combination of LBP and CS also is not satisfactory in the face recognition task for the heterogeneous database because redundancy is one important factor in CS method but LBP is not. In short, SS-CS will have a good performance in the face recognition task for heterogeneous database. On the other side, the redundancy is important to the recognition method with CS technique. This idea will be opposite to the traditional recognition method (such as LBP) which will be more concerned about specificity. However, this experiment shows that CS algorithm with redundancy feature extraction can have positive significance for accomplishing the pattern recognition task especially with SSS problem. Our future work focus on the improvement of the current system architecture in order to make the detection and tracking algorithms more robust and faster. Better and effecient methods for object detection in the unwrapped pictures and recogntion of face with higher and faster recognition rate are the heart of forthcoming studies. Moreover, our upcoming work will be oriented toward merging more biometric analysis like iris and gait to have a robust and mobile multimodal biometric system.

Fig. 1 .

 1 Fig. 1. Prototype of vision system.

Fig. 3 .

 3 Fig. 3. Unified projection model.

Fig. 4 .

 4 Fig. 4. Original catadioptric image.

Fig. 5 .

 5 Fig. 5. Unwrapped image obtained by spherical transformation.

Fig. 6 .

 6 Fig. 6. Haar Like Features.

Fig. 7 .

 7 (a) & Fig. 7.(b)

Fig. 7 .

 7 Fig. 7. (a). Detected face Image (b). Zoomed Image omnidirectional referential:

Fig. 8 .

 8 Fig. 8. Average Images.

Fig. 9 .

 9 Fig. 9. Output of Eigenfaces.

5. 2

 2 NOBA Database The Nomad Biometric Authentication (NOBA) project focuses on the development of biometric technologies for strong authentication and secured data exchange. This project is undertaken as part of the Franco-British cooperation INTERREGIVA and the GRR EEM (major research in Electronics, Energy and Materials). It brings together two research teams, IRSEEM and the Department of Electronics of the University of Kent. The ultimate goal of the NOBA project is the development of a smart system that cooperatively uses solutions based on vision rely on fixed devices embedded on a mobile platform. Its main applications would be in Electronic surveillance, ambient control of restricted access areas or other security systems. NOBA database includes 3 Subsets : Gait database, Face database and Iris database. In NOBA Face DataBase, we have 10 subjects (or persons). The face data are captured from 2 sensors : Pan Tilt Zoom (PTZ) camera & Camera with infrared light (2D digitizer). During building the Face database, we take into account variations of Poses of head and eyes direction (various poses), Facial expressions (various expressions), Illuminations conditions (various illuminations). The combination of expressions under illumination and poses under expressions, 4 classes are defined : -C1 : Facial expressions descriptors, -C2 : Mouth movements descriptors, -C3 : Pose of head and eye direction descriptors, -C4 : Various Illuminations.

Fig. 10 .

 10 Fig. 10. The flowchart of LBP and CS with face recognition.

Fig. 11 .

 11 Fig. 11. Several examples in the heterogeneous face database.

Fig. 12 .

 12 Fig. 12. Experimental results based on the heterogeneous database : (a). NOBA+ORL+CSU. (b). NOBA+ORL+CSU Only NOBA Image as test Object.

Fig. 13 .

 13 Fig. 13. Two classification standards for NOBA database : (a). Different behaviors. (b). Different subjects.

Fig. 14 .

 14 Fig. 14. Experimental results for two classification standards: (a). NOBA with 7 classes (each number is 2). (b). NOBA with 2 classes (each number is 15).

Fig. 14 (

 14 a) is the classification result with behavior information in NOBA. It shows that either of SS-CS and LBP-CS work better than LBP-NN. It is obvious that there is serious SSS problem in this classification standard. Although the recognition rate of SS-CS and LBP-CS is not good enough, it implies that the performance of recognition system with SSS problem can be improved effectively by using CS algorithm. Fig.14 (b)shows the result based on the subject´s difference. It can easily be seen that SS-CS has the best recognition rate in all three.

Table 1 .

 1 Noba Database.

	Image Features
	Image 1: Emotional Expression of Smiling
	Image 2: Laughter
	Image 3: Anger
	Image 4: Surprise
	Image 5: Eyes Closed
	Image 6: Fcae with high illumination
	Image 7: Tilt UP 30 •
	Image 8: Tilt Right 30 •
	Image 9: Tilt Left 90 •
	Image 10: Tilt Left 60 •
	Image 11: Tilt Left 30 •
	Image 12: Tilt Right 60 •
	Image 13: Tilt Right 90 •
	Image 14: Tilt Down 30 •
	Image 15: Frontal View Neutral Face
	Image 16: Face with Low illumination

Table 2 .

 2 Results of test subjects s45 and s50 with non-trained faces.

	Nearest Truth	Wrong/Right Confidence
	50	50	correct	0.925854
	45	45	correct	0.938389
	50	50	correct	0.882469
	50	50	correct	0.945845

Table 3 .

 3 Results of different trained and non-trained faces.

	Nearest	Truth Wrong/orrect Confidence
	50	50	Correct	0.924261
	45	45	Correct	1.000000
	23	23	Correct	0.971391
	26	23	Correct	0.936796

This work is part of the NOmad Biometric Authentication (NOBA) project funded by ERDF under the Interreg IVA program (Ref. No. 4051) in collaboration with the University of Kent.

Acknowledgments

The authors would like to thank all people who are given volunteers for the construction of NOBA Database. We thank them for their availability during image data acquisition.