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Author Juan Ramon Terven Salinas; Joaquin Salas; Bogdan Raducanu edit   pdf
url  doi
openurl 
  Title New Opportunities for Computer Vision-Based Assistive Technology Systems for the Visually Impaired Type Journal Article
  Year 2014 Publication Computer Abbreviated Journal COMP  
  Volume 47 Issue 4 Pages 52-58  
  Keywords  
  Abstract Computing advances and increased smartphone use gives technology system designers greater flexibility in exploiting computer vision to support visually impaired users. Understanding these users' needs will certainly provide insight for the development of improved usability of computing devices.  
  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 0018-9162 ISBN Medium  
  Area (up) Expedition Conference  
  Notes LAMP; Approved no  
  Call Number Admin @ si @ TSR2014a Serial 2317  
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Author Bogdan Raducanu; Fadi Dornaika edit   pdf
doi  openurl
  Title Embedding new observations via sparse-coding for non-linear manifold learning Type Journal Article
  Year 2014 Publication Pattern Recognition Abbreviated Journal PR  
  Volume 47 Issue 1 Pages 480-492  
  Keywords  
  Abstract Non-linear dimensionality reduction techniques are affected by two critical aspects: (i) the design of the adjacency graphs, and (ii) the embedding of new test data-the out-of-sample problem. For the first aspect, the proposed solutions, in general, were heuristically driven. For the second aspect, the difficulty resides in finding an accurate mapping that transfers unseen data samples into an existing manifold. Past works addressing these two aspects were heavily parametric in the sense that the optimal performance is only achieved for a suitable parameter choice that should be known in advance. In this paper, we demonstrate that the sparse representation theory not only serves for automatic graph construction as shown in recent works, but also represents an accurate alternative for out-of-sample embedding. Considering for a case study the Laplacian Eigenmaps, we applied our method to the face recognition problem. To evaluate the effectiveness of the proposed out-of-sample embedding, experiments are conducted using the K-nearest neighbor (KNN) and Kernel Support Vector Machines (KSVM) classifiers on six public face datasets. The experimental results show that the proposed model is able to achieve high categorization effectiveness as well as high consistency with non-linear embeddings/manifolds obtained in batch modes.  
  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 (up) Expedition Conference  
  Notes LAMP; Approved no  
  Call Number Admin @ si @ RaD2013b Serial 2316  
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Author Cesar Isaza; Joaquin Salas; Bogdan Raducanu edit   pdf
doi  openurl
  Title Rendering ground truth data sets to detect shadows cast by static objects in outdoors Type Journal Article
  Year 2014 Publication Multimedia Tools and Applications Abbreviated Journal MTAP  
  Volume 70 Issue 1 Pages 557-571  
  Keywords Synthetic ground truth data set; Sun position; Shadow detection; Static objects shadow detection  
  Abstract In our work, we are particularly interested in studying the shadows cast by static objects in outdoor environments, during daytime. To assess the accuracy of a shadow detection algorithm, we need ground truth information. The collection of such information is a very tedious task because it is a process that requires manual annotation. To overcome this severe limitation, we propose in this paper a methodology to automatically render ground truth using a virtual environment. To increase the degree of realism and usefulness of the simulated environment, we incorporate in the scenario the precise longitude, latitude and elevation of the actual location of the object, as well as the sun’s position for a given time and day. To evaluate our method, we consider a qualitative and a quantitative comparison. In the quantitative one, we analyze the shadow cast by a real object in a particular geographical location and its corresponding rendered model. To evaluate qualitatively the methodology, we use some ground truth images obtained both manually and automatically.  
  Address  
  Corporate Author Thesis  
  Publisher Springer US Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1380-7501 ISBN Medium  
  Area (up) Expedition Conference  
  Notes LAMP; Approved no  
  Call Number Admin @ si @ ISR2014 Serial 2229  
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Author Juan Ramon Terven Salinas; Joaquin Salas; Bogdan Raducanu edit  doi
isbn  openurl
  Title Robust Head Gestures Recognition for Assistive Technology Type Book Chapter
  Year 2014 Publication Pattern Recognition Abbreviated Journal  
  Volume 8495 Issue Pages 152-161  
  Keywords  
  Abstract This paper presents a system capable of recognizing six head gestures: nodding, shaking, turning right, turning left, looking up, and looking down. The main difference of our system compared to other methods is that the Hidden Markov Models presented in this paper, are fully connected and consider all possible states in any given order, providing the following advantages to the system: (1) allows unconstrained movement of the head and (2) it can be easily integrated into a wearable device (e.g. glasses, neck-hung devices), in which case it can robustly recognize gestures in the presence of ego-motion. Experimental results show that this approach outperforms common methods that use restricted HMMs for each gesture.  
  Address  
  Corporate Author Thesis  
  Publisher Springer International Publishing Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title LNCS  
  Series Volume Series Issue Edition  
  ISSN 0302-9743 ISBN 978-3-319-07490-0 Medium  
  Area (up) Expedition Conference  
  Notes LAMP; Approved no  
  Call Number Admin @ si @ TSR2014b Serial 2505  
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Author Xim Cerda-Company; C. Alejandro Parraga; Xavier Otazu edit  openurl
  Title Which tone-mapping is the best? A comparative study of tone-mapping perceived quality Type Abstract
  Year 2014 Publication Perception Abbreviated Journal  
  Volume 43 Issue Pages 106  
  Keywords  
  Abstract Perception 43 ECVP Abstract Supplement
High-dynamic-range (HDR) imaging refers to the methods designed to increase the brightness dynamic range present in standard digital imaging techniques. This increase is achieved by taking the same picture under di erent exposure values and mapping the intensity levels into a single image by way of a tone-mapping operator (TMO). Currently, there is no agreement on how to evaluate the quality
of di erent TMOs. In this work we psychophysically evaluate 15 di erent TMOs obtaining rankings based on the perceived properties of the resulting tone-mapped images. We performed two di erent experiments on a CRT calibrated display using 10 subjects: (1) a study of the internal relationships between grey-levels and (2) a pairwise comparison of the resulting 15 tone-mapped images. In (1) observers internally matched the grey-levels to a reference inside the tone-mapped images and in the real scene. In (2) observers performed a pairwise comparison of the tone-mapped images alongside the real scene. We obtained two rankings of the TMOs according their performance. In (1) the best algorithm
was ICAM by J.Kuang et al (2007) and in (2) the best algorithm was a TMO by Krawczyk et al (2005). Our results also show no correlation between these two rankings.
 
  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 (up) Expedition Conference ECVP  
  Notes NEUROBIT; 600.074 Approved no  
  Call Number Admin @ si @ CPO2014 Serial 2527  
Permanent link to this record
 

 
Author Manuel Graña; Bogdan Raducanu edit  doi
openurl 
  Title Special Issue on Bioinspired and knowledge based techniques and applications Type Journal Article
  Year 2015 Publication Neurocomputing Abbreviated Journal NEUCOM  
  Volume Issue Pages 1-3  
  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 (up) Expedition Conference  
  Notes LAMP; Approved no  
  Call Number Admin @ si @ GrR2015 Serial 2598  
Permanent link to this record
 

 
Author Bogdan Raducanu; Alireza Bosaghzadeh; Fadi Dornaika edit  openurl
  Title Facial Expression Recognition based on Multi-view Observations with Application to Social Robotics Type Conference Article
  Year 2014 Publication 1st Workshop on Computer Vision for Affective Computing Abbreviated Journal  
  Volume Issue Pages 1-8  
  Keywords  
  Abstract Human-robot interaction is a hot topic nowadays in the social robotics community. One crucial aspect is represented by the affective communication which comes encoded through the facial expressions. In this paper, we propose a novel approach for facial expression recognition, which exploits an efficient and adaptive graph-based label propagation (semi-supervised mode) in a multi-observation framework. The facial features are extracted using an appearance-based 3D face tracker, view- and texture independent. Our method has been extensively tested on the CMU dataset, and has been conveniently compared with other methods for graph construction. With the proposed approach, we developed an application for an AIBO robot, in which it mirrors the recognized facial
expression.
 
  Address Singapore; November 2014  
  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 (up) Expedition Conference ACCV  
  Notes LAMP; Approved no  
  Call Number Admin @ si @ RBD2014 Serial 2599  
Permanent link to this record
 

 
Author Bogdan Raducanu; Alireza Bosaghzadeh; Fadi Dornaika edit  doi
openurl 
  Title Multi-observation Face Recognition in Videos based on Label Propagation Type Conference Article
  Year 2015 Publication 6th Workshop on Analysis and Modeling of Faces and Gestures AMFG2015 Abbreviated Journal  
  Volume Issue Pages 10-17  
  Keywords  
  Abstract In order to deal with the huge amount of content generated by social media, especially for indexing and retrieval purposes, the focus shifted from single object recognition to multi-observation object recognition. Of particular interest is the problem of face recognition (used as primary cue for persons’ identity assessment), since it is highly required by popular social media search engines like Facebook and Youtube. Recently, several approaches for graph-based label propagation were proposed. However, the associated graphs were constructed in an ad-hoc manner (e.g., using the KNN graph) that cannot cope properly with the rapid and frequent changes in data appearance, a phenomenon intrinsically related with video sequences. In this paper, we
propose a novel approach for efficient and adaptive graph construction, based on a two-phase scheme: (i) the first phase is used to adaptively find the neighbors of a sample and also to find the adequate weights for the minimization function of the second phase; (ii) in the second phase, the
selected neighbors along with their corresponding weights are used to locally and collaboratively estimate the sparse affinity matrix weights. Experimental results performed on Honda Video Database (HVDB) and a subset of video
sequences extracted from the popular TV-series ’Friends’ show a distinct advantage of the proposed method over the existing standard graph construction methods.
 
  Address Boston; USA; June 2015  
  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 (up) Expedition Conference CVPRW  
  Notes LAMP; 600.068; 600.072; Approved no  
  Call Number Admin @ si @ RBD2015 Serial 2627  
Permanent link to this record
 

 
Author Xavier Otazu; Olivier Penacchio; Xim Cerda-Company edit  url
openurl 
  Title Brightness and colour induction through contextual influences in V1 Type Conference Article
  Year 2015 Publication Scottish Vision Group 2015 SGV2015 Abbreviated Journal  
  Volume 12 Issue 9 Pages 1208-2012  
  Keywords  
  Abstract  
  Address Carnoustie; Scotland; March 2015  
  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 (up) Expedition Conference SGV  
  Notes NEUROBIT; Approved no  
  Call Number Admin @ si @ OPC2015a Serial 2632  
Permanent link to this record
 

 
Author Olivier Penacchio; Xavier Otazu; A. wilkins; J. Harris edit  url
openurl 
  Title Uncomfortable images prevent lateral interactions in the cortex from providing a sparse code Type Conference Article
  Year 2015 Publication European Conference on Visual Perception ECVP2015 Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address Liverpool; uk; August 2015  
  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 (up) Expedition Conference ECVP  
  Notes NEUROBIT; Approved no  
  Call Number Admin @ si @ POW2015 Serial 2633  
Permanent link to this record
 

 
Author Xavier Otazu; Olivier Penacchio; Xim Cerda-Company edit  openurl
  Title An excitatory-inhibitory firing rate model accounts for brightness induction, colour induction and visual discomfort Type Conference Article
  Year 2015 Publication Barcelona Computational, Cognitive and Systems Neuroscience Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address Barcelona; June 2015  
  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 (up) Expedition Conference BARCCSYN  
  Notes NEUROBIT; Approved no  
  Call Number Admin @ si @ OPC2015b Serial 2634  
Permanent link to this record
 

 
Author Fadi Dornaika; Bogdan Raducanu; Alireza Bosaghzadeh edit  openurl
  Title Facial expression recognition based on multi observations with application to social robotics Type Book Chapter
  Year 2015 Publication Emotional and Facial Expressions: Recognition, Developmental Differences and Social Importance Abbreviated Journal  
  Volume Issue Pages 153-166  
  Keywords  
  Abstract Human-robot interaction is a hot topic nowadays in the social robotics
community. One crucial aspect is represented by the affective communication
which comes encoded through the facial expressions. In this chapter, we propose a novel approach for facial expression recognition, which exploits an efficient and adaptive graph-based label propagation (semi-supervised mode) in a multi-observation framework. The facial features are extracted using an appearance-based 3D face tracker, viewand texture independent. Our method has been extensively tested on the CMU dataset, and has been conveniently compared with other methods for graph construction. With the proposed approach, we developed an application for an AIBO robot, in which it mirrors the recognized facial
expression.
 
  Address  
  Corporate Author Thesis  
  Publisher Nova Science publishers Place of Publication Editor Bruce Flores  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area (up) Expedition Conference  
  Notes LAMP; Approved no  
  Call Number Admin @ si @ DRB2015 Serial 2720  
Permanent link to this record
 

 
Author Juan Ramon Terven Salinas; Bogdan Raducanu; Maria Elena Meza-de-Luna; Joaquin Salas edit   pdf
doi  openurl
  Title Head-gestures mirroring detection in dyadic social linteractions with computer vision-based wearable devices Type Journal Article
  Year 2016 Publication Neurocomputing Abbreviated Journal NEUCOM  
  Volume 175 Issue B Pages 866–876  
  Keywords Head gestures recognition; Mirroring detection; Dyadic social interaction analysis; Wearable devices  
  Abstract During face-to-face human interaction, nonverbal communication plays a fundamental role. A relevant aspect that takes part during social interactions is represented by mirroring, in which a person tends to mimic the non-verbal behavior (head and body gestures, vocal prosody, etc.) of the counterpart. In this paper, we introduce a computer vision-based system to detect mirroring in dyadic social interactions with the use of a wearable platform. In our context, mirroring is inferred as simultaneous head noddings displayed by the interlocutors. Our approach consists of the following steps: (1) facial features extraction; (2) facial features stabilization; (3) head nodding recognition; and (4) mirroring detection. Our system achieves a mirroring detection accuracy of 72% on a custom mirroring dataset.  
  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 (up) Expedition Conference  
  Notes LAMP; 600.072; 600.068; Approved no  
  Call Number Admin @ si @ TRM2016 Serial 2721  
Permanent link to this record
 

 
Author Juan Ramon Terven Salinas; Bogdan Raducanu; Maria Elena Meza-de-Luna; Joaquin Salas edit   pdf
url  doi
openurl 
  Title Evaluating Real-Time Mirroring of Head Gestures using Smart Glasses Type Conference Article
  Year 2015 Publication 16th IEEE International Conference on Computer Vision Workshops Abbreviated Journal  
  Volume Issue Pages 452-460  
  Keywords  
  Abstract Mirroring occurs when one person tends to mimic the non-verbal communication of their counterparts. Even though mirroring is a complex phenomenon, in this study, we focus on the detection of head-nodding as a simple non-verbal communication cue due to its significance as a gesture displayed during social interactions. This paper introduces a computer vision-based method to detect mirroring through the analysis of head gestures using wearable cameras (smart glasses). In addition, we study how such a method can be used to explore perceived competence. The proposed method has been evaluated and the experiments demonstrate how static and wearable cameras seem to be equally effective to gather the information required for the analysis.  
  Address Santiago de Chile; December 2015  
  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 (up) Expedition Conference ICCVW  
  Notes LAMP; 600.068; 600.072; Approved no  
  Call Number Admin @ si @ TRM2015 Serial 2722  
Permanent link to this record
 

 
Author Maria Elena Meza-de-Luna; Juan Ramon Terven Salinas; Bogdan Raducanu; Joaquin Salas edit   pdf
doi  openurl
  Title Assessing the Influence of Mirroring on the Perception of Professional Competence using Wearable Technology Type Journal Article
  Year 2016 Publication IEEE Transactions on Affective Computing Abbreviated Journal TAC  
  Volume 9 Issue 2 Pages 161-175  
  Keywords Mirroring; Nodding; Competence; Perception; Wearable Technology  
  Abstract Nonverbal communication is an intrinsic part in daily face-to-face meetings. A frequently observed behavior during social interactions is mirroring, in which one person tends to mimic the attitude of the counterpart. This paper shows that a computer vision system could be used to predict the perception of competence in dyadic interactions through the automatic detection of mirroring
events. To prove our hypothesis, we developed: (1) A social assistant for mirroring detection, using a wearable device which includes a video camera and (2) an automatic classifier for the perception of competence, using the number of nodding gestures and mirroring events as predictors. For our study, we used a mixed-method approach in an experimental design where 48 participants acting as customers interacted with a confederated psychologist. We found that the number of nods or mirroring events has a significant influence on the perception of competence. Our results suggest that: (1) Customer mirroring is a better predictor than psychologist mirroring; (2) the number of psychologist’s nods is a better predictor than the number of customer’s nods; (3) except for the psychologist mirroring, the computer vision algorithm we used worked about equally well whether it was acquiring images from wearable smartglasses or fixed cameras.
 
  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 (up) Expedition Conference  
  Notes LAMP; 600.072; Approved no  
  Call Number Admin @ si @ MTR2016 Serial 2826  
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