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Author (up) Agata Lapedriza edit  openurl
  Title Multitask Learning Techniques for Automatic Face Classification Type Book Whole
  Year 2009 Publication PhD Thesis, Universitat Autonoma de Barcelona-CVC Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract Automatic face classification is currently a popular research area in Computer Vision. It involves several subproblems, such as subject recognition, gender classification or subject verification.

Current systems of automatic face classification need a large amount of training data to robustly learn a task. However, the collection of labeled data is usually a difficult issue. For this reason, the research on methods that are able to learn from a small sized training set is essential.

The dependency on the abundance of training data is not so evident in human learning processes. We are able to learn from a very small number of examples, given that we use, additionally, some prior knowledge to learn a new task. For example, we frequently find patterns and analogies from other domains to reuse them in new situations, or exploit training data from other experiences.

In computer science, Multitask Learning is a new Machine Learning approach that studies this idea of knowledge transfer among different tasks, to overcome the effects of the small sample sized problem.

This thesis explores, proposes and tests some Multitask Learning methods specially developed for face classification purposes. Moreover, it presents two more contributions dealing with the small sample sized problem, out of the Multitask Learning context. The first one is a method to extract external face features, to be used as an additional information source in automatic face classification problems. The second one is an empirical study on the most suitable face image resolution to perform automatic subject recognition.
 
  Address Barcelona (Spain)  
  Corporate Author Thesis Ph.D. thesis  
  Publisher Ediciones Graficas Rey Place of Publication Editor Jordi Vitria;David Masip  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ Lap2009 Serial 1263  
Permanent link to this record
 

 
Author (up) Agata Lapedriza edit  openurl
  Title Face Classification using External Face Features Type Report
  Year 2005 Publication CVC Technical Report #83 Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address CVC (UAB)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ Lap2005 Serial 551  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; D.Sanchez edit  doi
isbn  openurl
  Title Emotions Classification using Facial Action Units Recognition Type Conference Article
  Year 2014 Publication 17th International Conference of the Catalan Association for Artificial Intelligence Abbreviated Journal  
  Volume 269 Issue Pages 55-64  
  Keywords  
  Abstract In this work we build a system for automatic emotion classification from image sequences. We analyze subtle changes in facial expressions by detecting a subset of 12 representative facial action units (AUs). Then, we classify emotions based on the output of these AUs classifiers, i.e. the presence/absence of AUs. We base the AUs classification upon a set of spatio-temporal geometric and appearance features for facial representation, fusing them within the emotion classifier. A decision tree is trained for emotion classifying, making the resulting model easy to interpret by capturing the combination of AUs activation that lead to a particular emotion. For Cohn-Kanade database, the proposed system classifies 7 emotions with a mean accuracy of near 90%, attaining a similar recognition accuracy in comparison with non-interpretable models that are not based in AUs detection.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN 978-1-61499-451-0 Medium  
  Area Expedition Conference CCIA  
  Notes OR;MV Approved no  
  Call Number Admin @ si @ LMS2014 Serial 2622  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; Jordi Vitria edit  openurl
  Title Subject Recognition Using a New Approach for Feature Extraction Type Conference Article
  Year 2008 Publication 3rd International Conference on Computer Vision Theory and Applications Abbreviated Journal  
  Volume 2 Issue Pages 61–66  
  Keywords  
  Abstract  
  Address Madeira (Portugal)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference VISAPP  
  Notes OR; MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LMV2008a Serial 980  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; Jordi Vitria edit  doi
openurl 
  Title On the Use of Independent Tasks for Face Recognition Type Conference Article
  Year 2008 Publication IEEE Computer Society Conference on Computer Vision and Pattern Recognition Abbreviated Journal  
  Volume Issue Pages 1–6  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference CVPR  
  Notes OR; MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LMV2008b Serial 1043  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; Jordi Vitria edit  openurl
  Title A Hierarchical Approach for Multi-task Logistic Regression Type Conference Article
  Year 2007 Publication 3rd Iberian Conference on Pattern Recognition and Image Analysis Abbreviated Journal  
  Volume 4478 Issue Pages 258–265  
  Keywords  
  Abstract  
  Address Girona (Spain)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor J. Marti et al.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title LNCS  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference IbPRIA  
  Notes OR; MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LMV2007a Serial 902  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; Jordi Vitria edit  openurl
  Title Face Verification using External Features Type Miscellaneous
  Year 2006 Publication 7th International Conference on Automatic Face and Gesture Recognition (FG´06), 132– 137 Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address Southampton (United Kingdom)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LMV2006a Serial 707  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; Jordi Vitria edit  doi
openurl 
  Title On the Use of External Face Features for Identity Verification Type Journal
  Year 2006 Publication Journal of Multimedia, 1(4): 11–20 Abbreviated Journal  
  Volume 1 Issue 4 Pages 11-20  
  Keywords Face Verification, Computer Vision, Machine Learning  
  Abstract In general automatic face classification applications images are captured in natural environments. In these cases, the performance is affected by variations in facial images related to illumination, pose, occlusion or expressions. Most of the existing face classification systems use only the internal features information, composed by eyes, nose and mouth, since they are more difficult to imitate. Nevertheless, nowadays a lot of applications not related to security are developed, and in these cases the information located at head, chin or ears zones (external features) can be useful to improve the current accuracies. However, the lack of a natural alignment in these areas makes difficult to extract these features applying classic Bottom-Up methods. In this paper, we propose a complete scheme based on a Top-Down reconstruction algorithm to extract external features of face images. To test our system we have performed face verification experiments using public databases, given that identity verification is a general task that has many real life applications. We have considered images uniformly illuminated, images with occlusions and images with high local changes in the illumination, and the obtained results show that the information contributed by the external features can be useful for verification purposes, specially significant when faces are partially occluded.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LMV2006b Serial 708  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; Jordi Vitria edit  openurl
  Title Are external face features useful for automatic face classification? Type Miscellaneous
  Year 2005 Publication IEEE Workshop on Face Recognition Grand Challenge Experiments, 151–ff Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address San Diego; CA; USA;  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LMV2005b Serial 547  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; David Masip; Jordi Vitria edit  url
openurl 
  Title The contribution of external features to face recognition Type Book Chapter
  Year 2005 Publication Pattern Recognition and Image Analysis (IbPRIA 2005), LNCS 3523: 537–544 Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address Estoril (Portugal)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LMV2005a Serial 546  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; Jaume Garcia; Ernest Valveny; Robert Benavente; Miquel Ferrer; Gemma Sanchez edit  openurl
  Title Una experiencia de aprenentatge basada en projectes en el ambit de la informatica Type Miscellaneous
  Year 2008 Publication V Jornades d’Innovacio Docent (UAB) Abbreviated Journal  
  Volume Issue Pages 63  
  Keywords  
  Abstract  
  Address Bellaterra (Spain)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR; IAM; DAG; CIC; MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LGV2008 Serial 1030  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; Jordi Vitria edit  openurl
  Title Experimental Study of the Usefulness of External Face Features for Face Classification Type Book Chapter
  Year 2005 Publication Artificial Intelligence Research and Development, IOS Press, 99–106 Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address Amsterdam  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LaV2005 Serial 610  
Permanent link to this record
 

 
Author (up) Agata Lapedriza; Santiago Segui; David Masip; Jordi Vitria edit  openurl
  Title A Sparse Bayesian Approach for Joint Feature Selection and Classifier Learning Type Journal
  Year 2008 Publication Pattern Analysis and Applications, Special Issue: Non–Parametric Distance–Based Classification Techniques and Their Applications, Abbreviated Journal  
  Volume 11 Issue 3-4 Pages 299-308  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ LSM2008 Serial 996  
Permanent link to this record
 

 
Author (up) Agnes Borras edit   pdf
openurl 
  Title Contributions to the Content-Based Image Retrieval Using Pictorial Queries Type Book Whole
  Year 2009 Publication PhD Thesis, Universitat Autonoma de Barcelona-CVC Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract The broad access to digital cameras, personal computers and Internet, has lead to the generation of large volumes of data in digital form. If we want an effective usage of this huge amount of data, we need automatic tools to allow the retrieval of relevant information. Image data is a particular type of information that requires specific techniques of description and indexing. The computer vision field that studies these kind of techniques is called Content-Based Image Retrieval (CBIR). Instead of using text-based descriptions, a system of CBIR deals on properties that are inherent in the images themselves. Hence, the feature-based description provides a universal via of image expression in contrast with the more than 6000 languages spoken in the world.
Nowadays, the CBIR is a dynamic focus of research that has derived in important applications for many professional groups. The potential fields of application can be such diverse as: the medical domain, the crime prevention, the protection of the intel- lectual property, the journalism, the graphic design, the web search, the preservation of cultural heritage, etc.
The definition on the role of the user is a key point in the development of a CBIR application. The user is in charge to formulate the queries from which the images are retrieved. We have centered our attention on the image retrieval techniques that use queries based on pictorial information. We have identified a taxonomy composed by four main query paradigms: query-by-selection, query-by-iconic-composition, query- by-sketch and query-by-paint. Each one of these paradigms allows a different degree of user expressivity. From a simple image selection, to a complete painting of the query, the user takes control of the input in the CBIR system.
Along the chapters of this thesis we have analyzed the influence that each query paradigm imposes in the internal operations of a CBIR system. Moreover, we have proposed a set of contributions that we have exemplified in the context of a final application.
 
  Address Barcelona (Spain)  
  Corporate Author Thesis Ph.D. thesis  
  Publisher Ediciones Graficas Rey Place of Publication Bellaterra Editor Josep Llados  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes DAG; Approved no  
  Call Number DAG @ dag @ Bor2009; IAM @ iam @ Bor2009 Serial 1269  
Permanent link to this record
 

 
Author (up) Agnes Borras edit  openurl
  Title High-Level Clothes Description Based on Colour-Texture Features. Type Miscellaneous
  Year 2002 Publication Director: J. Llados, Master Thesis. Abbreviated Journal  
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  Abstract  
  Address  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number DAG @ dag @ Bor2002 Serial 322  
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