| Records |
| Author |
Xim Cerda-Company; Xavier Otazu; Nilai Sallent; C. Alejandro Parraga |
| Title |
The effect of luminance differences on color assimilation |
Type |
Journal Article |
| Year |
2018 |
Publication |
Journal of Vision |
Abbreviated Journal |
JV |
| Volume |
18 |
Issue |
11 |
Pages  |
10-10 |
| Keywords |
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| Abstract |
The color appearance of a surface depends on the color of its surroundings (inducers). When the perceived color shifts towards that of the surroundings, the effect is called “color assimilation” and when it shifts away from the surroundings it is called “color contrast.” There is also evidence that the phenomenon depends on the spatial configuration of the inducer, e.g., uniform surrounds tend to induce color contrast and striped surrounds tend to induce color assimilation. However, previous work found that striped surrounds under certain conditions do not induce color assimilation but induce color contrast (or do not induce anything at all), suggesting that luminance differences and high spatial frequencies could be key factors in color assimilation. Here we present a new psychophysical study of color assimilation where we assessed the contribution of luminance differences (between the target and its surround) present in striped stimuli. Our results show that luminance differences are key factors in color assimilation for stimuli varying along the s axis of MacLeod-Boynton color space, but not for stimuli varying along the l axis. This asymmetry suggests that koniocellular neural mechanisms responsible for color assimilation only contribute when there is a luminance difference, supporting the idea that mutual-inhibition has a major role in color induction. |
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Expedition |
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Conference |
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| Notes |
NEUROBIT; 600.120; 600.128 |
Approved |
no |
| Call Number |
Admin @ si @ COS2018 |
Serial |
3148 |
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| Author |
Agata Lapedriza; David Masip; Jordi Vitria |
| 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 |
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| 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. |
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Edition |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
OR;MV |
Approved |
no |
| Call Number |
BCNPCL @ bcnpcl @ LMV2006b |
Serial |
708 |
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| Author |
Alicia Fornes; Sergio Escalera; Josep Llados; Gemma Sanchez |
| Title |
Symbol Recognition by Multi-class Blurred Shape Models |
Type |
Conference Article |
| Year |
2007 |
Publication |
Seventh IAPR International Workshop on Graphics Recognition |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
11–13 |
| Keywords |
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| Abstract |
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| Address |
Curitiba (Brazil) |
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Place of Publication |
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Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
GREC |
| Notes |
DAG; MILAB; HUPBA |
Approved |
no |
| Call Number |
BCNPCL @ bcnpcl @ FEL2007b |
Serial |
910 |
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| Author |
Sergio Escalera; Oriol Pujol; Petia Radeva |
| Title |
Recoding Error-Correcting Output Codes |
Type |
Conference Article |
| Year |
2009 |
Publication |
8th International Workshop of Multiple Classifier Systems |
Abbreviated Journal |
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| Volume |
5519 |
Issue |
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Pages |
11–21 |
| Keywords |
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| Abstract |
One of the most widely applied techniques to deal with multi- class categorization problems is the pairwise voting procedure. Recently, this classical approach has been embedded in the Error-Correcting Output Codes framework (ECOC). This framework is based on a coding step, where a set of binary problems are learnt and coded in a matrix, and a decoding step, where a new sample is tested and classified according to a comparison with the positions of the coded matrix. In this paper, we present a novel approach to redefine without retraining, in a problem-dependent way, the one-versus-one coding matrix so that the new coded information increases the generalization capability of the system. Moreover, the final classification can be tuned with the inclusion of a weighting matrix in the decoding step. The approach has been validated over several UCI Machine Learning repository data sets and two real multi-class problems: traffic sign and face categorization. The results show that performance improvements are obtained when comparing the new approach to one of the best ECOC designs (one-versus-one). Furthermore, the novel methodology obtains at least the same performance than the one-versus-one ECOC design. |
| Address |
Reykjavik (Iceland) |
| Corporate Author |
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Thesis |
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| Publisher |
Springer Berlin Heidelberg |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0302-9743 |
ISBN |
978-3-642-02325-5 |
Medium |
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| Area |
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Expedition |
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Conference |
MCS |
| Notes |
MILAB;HuPBA |
Approved |
no |
| Call Number |
BCNPCL @ bcnpcl @ EPR2009d |
Serial |
1190 |
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| Author |
Partha Pratim Roy; Umapada Pal; Josep Llados; Mathieu Nicolas Delalandre |
| Title |
Multi-Oriented and Multi-Sized Touching Character Segmentation using Dynamic Programming |
Type |
Conference Article |
| Year |
2009 |
Publication |
10th International Conference on Document Analysis and Recognition |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
11–15 |
| Keywords |
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| Abstract |
In this paper, we present a scheme towards the segmentation of English multi-oriented touching strings into individual characters. When two or more characters touch, they generate a big cavity region at the background portion. Using Convex Hull information, we use these background information to find some initial points to segment a touching string into possible primitive segments (a primitive segment consists of a single character or a part of a character). Next these primitive segments are merged to get optimum segmentation and dynamic programming is applied using total likelihood of characters as the objective function. SVM classifier is used to find the likelihood of a character. To consider multi-oriented touching strings the features used in the SVM are invariant to character orientation. Circular ring and convex hull ring based approach has been used along with angular information of the contour pixels of the character to make the feature rotation invariant. From the experiment, we obtained encouraging results. |
| Address |
Barcelona, Spain |
| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1520-5363 |
ISBN |
978-1-4244-4500-4 |
Medium |
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| Area |
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Expedition |
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Conference |
ICDAR |
| Notes |
DAG |
Approved |
no |
| Call Number |
DAG @ dag @ RPL2009a |
Serial |
1240 |
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| Author |
Murad Al Haj; Carles Fernandez; Zhanwu Xiong; Ivan Huerta; Jordi Gonzalez; Xavier Roca |
| Title |
Beyond the Static Camera: Issues and Trends in Active Vision |
Type |
Book Chapter |
| Year |
2011 |
Publication |
Visual Analysis of Humans: Looking at People |
Abbreviated Journal |
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| Volume |
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Issue |
2 |
Pages |
11-30 |
| Keywords |
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| Abstract |
Maximizing both the area coverage and the resolution per target is highly desirable in many applications of computer vision. However, with a limited number of cameras viewing a scene, the two objectives are contradictory. This chapter is dedicated to active vision systems, trying to achieve a trade-off between these two aims and examining the use of high-level reasoning in such scenarios. The chapter starts by introducing different approaches to active cameras configurations. Later, a single active camera system to track a moving object is developed, offering the reader first-hand understanding of the issues involved. Another section discusses practical considerations in building an active vision platform, taking as an example a multi-camera system developed for a European project. The last section of the chapter reflects upon the future trends of using semantic factors to drive smartly coordinated active systems. |
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Thesis |
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| Publisher |
Springer London |
Place of Publication |
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Editor |
Th.B. Moeslund; A. Hilton; V. Krüger; L. Sigal |
| Language |
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Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
978-0-85729-996-3 |
Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
ISE |
Approved |
no |
| Call Number |
Admin @ si @ AFX2011 |
Serial |
1814 |
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| Author |
Cesar Isaza; Joaquin Salas; Bogdan Raducanu |
| Title |
Synthetic ground truth dataset to detect shadow cast by static objects in outdoor |
Type |
Conference Article |
| Year |
2012 |
Publication |
1st International Workshop on Visual Interfaces for Ground Truth Collection in Computer Vision Applications |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
art. 11 |
| Keywords |
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| Abstract |
In this paper, we propose a precise synthetic ground truth dataset to study the problem of detection of the shadows cast by static objects in outdoor environments during extended periods of time (days). For our dataset, we have created a virtual scenario using a rendering software. To increase the realism of the simulated environment, we have defined the scenario in a precise geographical location. In our dataset the sun is by far the main illumination source. The sun position during the simulation time takes into consideration factors related to the geographical location, such as the latitude, longitude, elevation above sea level, and precise image capturing day and time. In our simulation the camera remains fixed. The dataset consists of seven days of simulation, from 10:00am to 5:00pm. Images are captured every 10 seconds. The shadows' ground truth is automatically computed by the rendering software. |
| Address |
Capri, Italy |
| Corporate Author |
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Thesis |
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| Publisher |
ACM |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
978-1-4503-1405-3 |
Medium |
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| Area |
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Expedition |
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Conference |
VIGTA |
| Notes |
OR;MV |
Approved |
no |
| Call Number |
Admin @ si @ ISR2012a |
Serial |
2037 |
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| Author |
Sergio Escalera; Oriol Pujol; Eric Laciar; Jordi Vitria; Esther Pueyo; Petia Radeva |
| Title |
Coronary Damage Classification of Patients with the Chagas Disease with Error-Correcting Output Codes |
Type |
Conference Article |
| Year |
2008 |
Publication |
Intelligent Systems, 4th International IEEE Conference, 6–8 setembre 2008. |
Abbreviated Journal |
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| Volume |
2 |
Issue |
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Pages |
12–17 |
| Keywords |
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| Abstract |
The Chagaspsila disease is endemic in all Latin America, affecting millions of people in the continent. In order to diagnose and treat the Chagaspsila disease, it is important to detect and measure the coronary damage of the patient. In this paper, we analyze and categorize patients into different groups based on the coronary damage produced by the disease. Based on the features of the heart cycle extracted using high resolution ECG, a multi-class scheme of error-correcting output codes (ECOC) is formulated and successfully applied. The results show that the proposed scheme obtains significant performance improvements compared to previous works and state-of-the-art ECOC designs. |
| Address |
Varna (Bulgaria) |
| Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
IS’08 |
| Notes |
MILAB; OR;HuPBA;MV |
Approved |
no |
| Call Number |
BCNPCL @ bcnpcl @ EPL2008 |
Serial |
1042 |
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| Author |
Sergio Escalera; Oriol Pujol; Petia Radeva; Jordi Vitria; Maria Teresa Anguera |
| Title |
Automatic Detection of Dominance and Expected Interest |
Type |
Journal Article |
| Year |
2010 |
Publication |
EURASIP Journal on Advances in Signal Processing |
Abbreviated Journal |
EURASIPJ |
| Volume |
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Issue |
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Pages |
12 |
| Keywords |
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| Abstract |
Article ID 491819
Social Signal Processing is an emergent area of research that focuses on the analysis of social constructs. Dominance and interest are two of these social constructs. Dominance refers to the level of influence a person has in a conversation. Interest, when referred in terms of group interactions, can be defined as the degree of engagement that the members of a group collectively display during their interaction. In this paper, we argue that only using behavioral motion information, we are able to predict the interest of observers when looking at face-to-face interactions as well as the dominant people. First, we propose a simple set of movement-based features from body, face, and mouth activity in order to define a higher set of interaction indicators. The considered indicators are manually annotated by observers. Based on the opinions obtained, we define an automatic binary dominance detection problem and a multiclass interest quantification problem. Error-Correcting Output Codes framework is used to learn to rank the perceived observer's interest in face-to-face interactions meanwhile Adaboost is used to solve the dominant detection problem. The automatic system shows good correlation between the automatic categorization results and the manual ranking made by the observers in both dominance and interest detection problems. |
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Thesis |
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Place of Publication |
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Editor |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1110-8657 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
OR;MILAB;HUPBA;MV |
Approved |
no |
| Call Number |
BCNPCL @ bcnpcl @ EPR2010d |
Serial |
1283 |
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| Author |
Bogdan Raducanu; Fadi Dornaika |
| Title |
Dynamic Vs. Static Recognition of Facial Expressions |
Type |
Book Chapter |
| Year |
2008 |
Publication |
Ambient Intelligence. European Conference |
Abbreviated Journal |
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| Volume |
5355 |
Issue |
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Pages |
13–25 |
| Keywords |
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| Abstract |
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| Address |
Nuremberg (Germany) |
| Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
Rabuñal |
| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
LNCS |
| Series Volume |
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Series Issue |
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Edition |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
AMI |
| Notes |
OR; MV |
Approved |
no |
| Call Number |
BCNPCL @ bcnpcl @ RaD2008 |
Serial |
1035 |
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| Author |
Ernest Valveny; Miquel Ferrer |
| Title |
Application of Graph Embedding to Solve Graph Matchin Problems |
Type |
Conference Article |
| Year |
2008 |
Publication |
Colloque International Francophone sur l’Ecrit et le Document |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
13–18 |
| Keywords |
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| Abstract |
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| Address |
Rouen (France) |
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Thesis |
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Editor |
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Summary Language |
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Original Title |
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Series Title |
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Edition |
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ISBN |
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Medium |
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Expedition |
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Conference |
CIFED’08 |
| Notes |
DAG |
Approved |
no |
| Call Number |
DAG @ dag @ VaF2008 |
Serial |
1063 |
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| Author |
Salim Jouili; Salvatore Tabbone; Ernest Valveny |
| Title |
Evaluation of graph matching measures for documents retrieval |
Type |
Conference Article |
| Year |
2009 |
Publication |
In proceedings of 8th IAPR International Workshop on Graphics Recognition |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
13–21 |
| Keywords |
Graph Matching; Graph retrieval; structural representation; Performance Evaluation |
| Abstract |
In this paper we evaluate four graph distance measures. The analysis is performed for document retrieval tasks. For this aim, different kind of documents are used which include line drawings (symbols), ancient documents (ornamental letters), shapes and trademark-logos. The experimental results show that the performance of each grahp distance measure depends on the kind of data and the graph representation technique. |
| Address |
La Rochelle, France |
| Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0302-9743 |
ISBN |
978-3-642-13727-3 |
Medium |
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Expedition |
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Conference |
GREC |
| Notes |
DAG |
Approved |
no |
| Call Number |
DAG @ dag @ JTV2009a |
Serial |
1230 |
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| Author |
Francesco Ciompi; Oriol Pujol; E Fernandez-Nofrerias; J. Mauri; Petia Radeva |
| Title |
Conditional Random Fields for image segmentation in Intravascular Ultrasound |
Type |
Conference Article |
| Year |
2010 |
Publication |
Medical Image Computing in Catalunya: Graduate Student Workshop |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
13–14 |
| Keywords |
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| Abstract |
We present a Conditional Random Fields based approach for segmenting Intravascular Ultrasond (IVUS) images. The presented method uses a contextual discriminative graphical model to deal with the presence of distorsions and artifacts in IVUS images, that turns the segmentation of interesting regions into a difficult task. An accurate lumen segmentation on IVUS longitudinal images is achieved. |
| Address |
Girona |
| Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISBN |
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Medium |
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Expedition |
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Conference |
MICCAT |
| Notes |
MILAB;HUPBA |
Approved |
no |
| Call Number |
BCNPCL @ bcnpcl @ CPF2010 |
Serial |
1453 |
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| Author |
Thierry Brouard; A. Delaplace; Muhammad Muzzamil Luqman; H. Cardot; Jean-Yves Ramel |
| Title |
Design of Evolutionary Methods Applied to the Learning of Bayesian Nerwork Structures |
Type |
Book Chapter |
| Year |
2010 |
Publication |
Bayesian Network |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
13-37 |
| Keywords |
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| Abstract |
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| Address |
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Thesis |
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| Publisher |
Sciyo |
Place of Publication |
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Editor |
Ahmed Rebai |
| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
978-953-307-124-4 |
Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
no |
| Call Number |
Admin @ si @ BDL2010 |
Serial |
1461 |
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| Author |
Jose Carlos Rubio; Joan Serrat; Antonio Lopez |
| Title |
Video Co-segmentation |
Type |
Conference Article |
| Year |
2012 |
Publication |
11th Asian Conference on Computer Vision |
Abbreviated Journal |
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| Volume |
7725 |
Issue |
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Pages |
13-24 |
| Keywords |
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| Abstract |
Segmentation of a single image is in general a highly underconstrained problem. A frequent approach to solve it is to somehow provide prior knowledge or constraints on how the objects of interest look like (in terms of their shape, size, color, location or structure). Image co-segmentation trades the need for such knowledge for something much easier to obtain, namely, additional images showing the object from other viewpoints. Now the segmentation problem is posed as one of differentiating the similar object regions in all the images from the more varying background. In this paper, for the first time, we extend this approach to video segmentation: given two or more video sequences showing the same object (or objects belonging to the same class) moving in a similar manner, we aim to outline its region in all the frames. In addition, the method works in an unsupervised manner, by learning to segment at testing time. We compare favorably with two state-of-the-art methods on video segmentation and report results on benchmark videos. |
| Address |
Daejeon, Korea |
| Corporate Author |
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Thesis |
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| Publisher |
Springer Berlin Heidelberg |
Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
LNCS |
| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0302-9743 |
ISBN |
978-3-642-37443-2 |
Medium |
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| Area |
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Expedition |
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Conference |
ACCV |
| Notes |
ADAS |
Approved |
no |
| Call Number |
Admin @ si @ RSL2012d |
Serial |
2153 |
| Permanent link to this record |
