Javier Cruz

Journal publications [5]

2013

Cruz J., Bierlaire M., Thiran J. (2013). Sample and Pixel Weighting Strategies for Robust Incremental Visual Tracking. IEEE Transactions on Circuits and Systems for Video Technology 23 (5):898-911


@Article{CruzBierThir13,
  author = {Javier Cruz and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Sample and Pixel Weighting Strategies for Robust Incremental Visual Tracking},
  journal = {IEEE Transactions on  Circuits and Systems for Video Technology},
  year = {2013},
  volume = {23},
  number = {5},
  pages = {898-911},
  DOI = {10.1109/TCSVT.2013.2249374 },
  note = {Accepted on Dec 25, 2012}}}

2012

Cruz J., Bogdanova I., Paquier B., Bierlaire M., Thiran J. (2012). Scale Invariant Feature Transform on the Sphere: Theory and Applications. International Journal of Computer Vision 98 (2):217-241

A SIFT algorithm in spherical coordinates for omnidirectional images is proposed. This algorithm can generate two types of local descriptors, Local Spherical Descriptors and Local Planar Descriptors. With the first ones, point matching between two omnidirectional images can be performed, and with the second ones, the same matching process can be done but between omnidirectional and planar images. Furthermore, a planar to spherical mapping is introduced and an algorithm for its estimation is given. This mapping allows to extract objects from an omnidirectional image given their SIFT descriptors in a planar image. Several experiments, confirming the promising and accurate performance of the system, are conducted.
```
@Article{CruzBogdPaquBierThir09,
  author = {Javier Cruz and Iva Bogdanova and Beno{\^\i}t Paquier and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Scale Invariant Feature Transform on the Sphere: Theory and Applications},
  journal = {International Journal of Computer Vision},
  year = {2012},
  volume = {98},
  number = {2},
  pages = {217-241},
  DOI = {10.1007/s11263-011-0505-4},
  note = {Accepted on Oct 21, 2011}}}
```

2011

Robin T., Bierlaire M., Cruz J. (2011). Dynamic facial expression recognition with a discrete choice model. Journal of Choice Modelling 4 (2):95-148

A generation of new models has been proposed to handle some complex human behaviors. These models account for the data ambiguity, and there- fore extend the application field of the discrete choice modeling. The facial expression recognition (FER) is highly relevant in this context. We develop a dynamic facial expression recognition (DFER) framework based on dis- crete choice models (DCM). The DFER consists in modeling the choice of a person who has to label a video sequence representing a facial expression. The originality is based on the the analysis of videos with discrete choice models as well as the explicit modeling of causal effects between the facial features and the recognition of the expression. Five models are proposed. The first assumes that only the last frame of the video triggers the choice of the expression. The second model has two components. The first captures the perception of the facial expression within each frame in the sequence, while the second determines which frame triggers the choice. The third model is an extension of the second model and assumes that the choice of the expression results from the average of perceptions within a group of frames. The fourth and fifth models integrate the panel effect inherent to the estimation data and are respectively extensing the first and second mod- els. The models are estimated using videos from the Facial Expressions and Emotions Database (FEED). Labeling data on the videos has been obtained using an internet survey available at http://transp-or2.epfl.ch/videosurvey/. The prediction capability of the models is studied in order to check their validity by cross-validation using the estimation data.
```
@Article{RobiBierCruz11,
  author = {Thomas Robin and Michel Bierlaire and Javier Cruz},
  title = {Dynamic facial expression recognition with a discrete choice model},
  journal = {Journal of Choice Modelling},
  year = {2011},
  volume = {4},
  number = {2},
  pages = {95-148},
  DOI = {10.1016/S1755-5345(13)70059-9},
  note = {Accepted on Jun 02, 2011}}}
```

2010

Sorci M., Antonini G., Cruz J., Robin T., Bierlaire M., Thiran J. (2010). Modelling human perception of static facial expressions. Image and Vision Computing 28 (5):790-806

A recent internet based survey of over 35'000 samples has shown that when different human observers are asked to assign labels to static human facial expressions, different individuals categorize differently the same image. This fact results in a lack of an unique ground-truth, an assumption held by the large majority of existing models for classification. This is especially true for highly ambiguous expressions, especially in the lack of a dynamic context. In this paper we propose to address this shortcoming by the use of Discrete Choice Models (DCM) to describe the choice a human observer is faced to when assigning labels to static facial expressions. Different models of increasing complexity are specified to capture the causal effect between features of an image and its associated expression, using several combinations of different measurements. The sets of measurements we used are largely inspired by FACS but also introduce some new ideas, specific to a static framework. These models are calibrated using maximum likelihood techniques and they are compared with each other using a likelihood ratio test, in order to test for significance in the improvement resulting from adding supplemental features. Through a cross-validation procedure we assess the validity of our approach against overfitting and we provide a comparison with an alternative model based on Neural Networks for benchmark purposes.
```
@Article{SorcAntoCruzRobiBierThir09,
  author = {Matteo Sorci and Gianluca Antonini and Javier Cruz and Thomas Robin and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Modelling human perception of static facial expressions},
  journal = {Image and Vision Computing},
  year = {2010},
  volume = {28},
  number = {5},
  pages = {790-806},
  DOI = {10.1016/j.imavis.2009.10.003},
  note = {Accepted on Oct 07, 2009}}}
```

2009

Robin T., Antonini G., Bierlaire M., Cruz J. (2009). Specification, estimation and validation of a pedestrian walking behavior model. Transportation Research Part B: Methodological 43 (1):36-56

We propose and validate a model for pedestrian walking behavior, based on discrete choice modeling. Two main types of behavior are identified: unconstrained and constrained. By unconstrained, we refer to behavior patterns which are independent from other individuals. The constrained patterns are captured by a leader-follower model and by a collision avoidance model. The spatial correlation between the alternatives is captured by a cross nested logit model. The model is estimated by maximum likelihood estimation on a real data set of pedestrian trajectories, manually tracked from video sequences. The model is successfully validated using a bi-directional flow data set, collected in controlled experimental conditions at Delft university.
```
@Article{RobiAntoBierCruz08,
  author = {Thomas Robin and Gianluca Antonini and Michel Bierlaire and Javier Cruz},
  title = {Specification, estimation and validation of a pedestrian walking behavior model},
  journal = {Transportation Research Part B: Methodological},
  year = {2009},
  volume = {43},
  number = {1},
  pages = {36-56},
  DOI = {10.1016/j.trb.2008.06.010},
  note = {Accepted on Jun 11, 2008}}}
```

Book chapters [1]

2010

Sorci M., Robin T., Cruz J., Bierlaire M., Thiran J., Antonini G. (2010) Capturing Human Perception of Facial Expressions by Discrete Choice Modelling. In S. Hess and A. Daly (ed) Choice Modelling: The State-of-the-Art and the State-of-Practice, Emerald Group Publishing Limited [ISBN 978-1-84950-772-1]


@InProceedings{SorcRobiCruzBierThirAnto10,
  author = {Matteo Sorci and Thomas Robin and Javier Cruz and Michel Bierlaire and Jean-Philippe Thiran and Gianluca Antonini},
  title = {Capturing Human Perception of Facial Expressions by Discrete Choice Modelling},
  year = {2010},
  booktile = {Choice Modelling: The State-of-the-Art and the State-of-Practice},
  editor = {S. Hess and A. Daly},
  publisher = {Emerald Group Publishing Limited},
  pages = {101-136}}}

Technical reports [6]

2011

Cruz J., Bierlaire M., Thiran J. (2011). Sample and Pixel Weighting Strategies for Robust Incremental Visual Tracking. Report TRANSP-OR 111027


@TechReport{CruzBierThir11,
  author = {Javier Cruz and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Sample and Pixel Weighting Strategies for Robust Incremental Visual Tracking},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2011},
  type = {Technical Report},
  number = {TRANSP-OR 111027},
  address = {Lausanne, Switzerland}}}

2010

Robin T., Bierlaire M., Cruz J. (2010). Dynamic facial expression recognition with a discrete choice model. Report TRANSP-OR 100423


@TechReport{RobiBierCruz_DynFacExpRec_10,
  author = {Thomas Robin and Michel Bierlaire and Javier Cruz},
  title = {Dynamic facial expression recognition with a discrete choice model},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2010},
  type = {Technical Report},
  number = {TRANSP-OR 100423},
  address = {Lausanne, Switzerland}}}

2009

Sorci M., Robin T., Cruz J., Bierlaire M., Thiran J. (2009). Modelling human perception of facial expressions. Report TRANSP-OR 090706


@TechReport{SorcRobiCruzBierThir09,
  author = {Matteo Sorci and Thomas Robin and Javier Cruz and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Modelling human perception of facial expressions},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2009},
  type = {Technical Report},
  number = {TRANSP-OR 090706},
  address = {Lausanne, Switzerland}}}

Cruz J., Bogdanova I., Paquier B., Bierlaire M., Thiran J. (2009). Scale Invariant Feature Transform on the Sphere: Theory and Applications. Report TRANSP-OR 090426


@TechReport{CruzBogdPaquBierThir09,
  author = {Javier Cruz and Iva Bogdanova and Beno{\^\i}t Paquier and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Scale Invariant Feature Transform on the Sphere: Theory and Applications},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2009},
  type = {Technical Report},
  number = {TRANSP-OR 090426},
  address = {Lausanne, Switzerland}}}

2008

Cruz J., Bierlaire M., Thiran J. (2008). Multiple-View Scenes: Reconstruction and Virtual Views. Report TRANSP-OR 080710


@TechReport{CruzBierThir08,
  author = {Javier Cruz and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Multiple-View Scenes: Reconstruction and Virtual Views},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2008},
  type = {Technical Report},
  number = {TRANSP-OR 080710},
  address = {Lausanne, Switzerland}}}

2007

Robin T., Antonini G., Bierlaire M., Cruz J. (2007). Specification, estimation and validation of a pedestrian walking behavior model. Report TRANSP-OR 071116


@TechReport{RobiAntoBierCruz07,
  author = {Thomas Robin and Gianluca Antonini and Michel Bierlaire and Javier Cruz},
  title = {Specification, estimation and validation of a pedestrian walking behavior model},
  institution = {Transport and Mobility Laboratory, Ecole Polytechnique F\'ed\'erale de Lausanne},
  year = {2007},
  type = {Technical Report},
  number = {TRANSP-OR 071116},
  address = {Lausanne, Switzerland}}}

Articles in conference proceedings [5]

2010

Robin T., Bierlaire M., Cruz J. (2010) Travellers well-being measuring and dynamic facial expression recognition. Proceedings of the World Conference on Transport Research July 11-15, Lisbonne, Portugal


@InProceedings{trobin_WCTR_10,
  author = {Thomas Robin and Michel Bierlaire and Javier Cruz},
  title = {Travellers well-being measuring and dynamic facial expression recognition},
  booktime = {Proceedings of the World Conference on Transport Research , July 11-15},
  year = {2010},
  address = {Lisbonne, Portugal}}}

2009

Robin T., Bierlaire M., Cruz J. (2009) Dynamic facial expression recognition using a behavioural model. Proceedings of the the 9th Swiss Transport Research Conference (STRC), September 9 - 11, 2009, Ascona, Switzerland


@InProceedings{Robin_STRC09,
  author = {Thomas Robin and Michel Bierlaire and Javier Cruz},
  title = {Dynamic facial expression recognition using a behavioural model},
  booktime = {Proceedings of the the 9th Swiss Transport Research Conference  (STRC), September 9 - 11, 2009},
  year = {2009},
  address = {Ascona, Switzerland}}}

2008

Robin T., Antonini G., Bierlaire M., Cruz J. (2008) Specification, estimation and validation of a pedestrian walking behaviour model. Proceedings of the European Transportation Research Conference (ETC), October 6-8, , Netherlands


@InProceedings{RobAntBieCru_ETC08,
  author = {Thomas Robin and Gianluca Antonini and Michel Bierlaire and Javier Cruz},
  title = {Specification, estimation and validation of a pedestrian walking behaviour model},
  booktime = {Proceedings of the European Transportation Research Conference (ETC), October 6-8},
  year = {2008},
  address = {, Netherlands}}}

Meynet J., Arsan T., Cruz J., Thiran J. (2008) Fast multi-view face tracking with pose estimation. Proceedings of the 16th European Signal Processing Conference (EUSIPCO2008), August 25-29, Lausanne, Switzerland


@InProceedings{MeynetArsanCruzThiran08,
  author = {Julien Meynet and Taner Arsan and Javier Cruz and Jean-Philippe Thiran},
  title = {Fast multi-view face tracking with pose estimation},
  booktime = {Proceedings of the 16th European Signal Processing Conference (EUSIPCO2008), August 25-29},
  year = {2008},
  address = {Lausanne, Switzerland}}}

Sorci M., Antonini G., Cerretani B., Cruz J., Robin T., Bierlaire M., Thiran J. (2008) Modelling human perception of static facial expressions. Proceedings of the 8th IEEE International Conference on Automatic Face and Gesture Recognition (FG2008), September 17-19, Amsterdam, The Netherlands


@InProceedings{SorciAntoCerCruzRobinBierThiran2008,
  author = {Matteo Sorci and Gianluca Antonini and Barbara Cerretani and Javier Cruz and Thomas Robin and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Modelling human perception of static facial expressions},
  booktime = {Proceedings of the 8th IEEE International Conference on Automatic Face and Gesture Recognition (FG2008), September 17-19},
  year = {2008},
  address = {Amsterdam, The Netherlands}}}

Talks [5]

2010

Cruz J. Combining Visual and Behavioural Models for Pedestrian Tracking October 25, 2010. Transp-OR Seminar Series, EPFL, Lausanne.


@Misc{CruzPEDTRACK10b,
  author = {Javier Cruz},
  title = {Combining Visual and Behavioural Models for Pedestrian Tracking},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/CruzPEDTRACK10b.pdf}},
  year = {2010},
  note = {Presented at Transp-OR Seminar Series, EPFL, Lausanne}}}

Cruz J. Behavioural Pedestrian Tracking (II) April 12, 2010. Transp-OR Seminar Series, EPFL, Lausanne.


@Misc{CruzPEDTRACK10a,
  author = {Javier Cruz},
  title = {Behavioural Pedestrian Tracking (II)},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/CruzPEDTRACK10a.pdf}},
  year = {2010},
  note = {Presented at Transp-OR Seminar Series, EPFL, Lausanne}}}

2009

Cruz J. Behavioural Pedestrian Tracking November 09, 2009. Transp-OR Seminar Series, EPFL, Lausanne.


@Misc{CruzPEDTRACK09,
  author = {Javier Cruz},
  title = {Behavioural Pedestrian Tracking},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/CruzPEDTRACK09.pdf}},
  year = {2009},
  note = {Presented at Transp-OR Seminar Series, EPFL, Lausanne}}}

2008

Cruz J., Meynet J., Arsan T., Thiran J. Fast multi-view face tracking with pose estimation August 26, 2008. 16th European Signal Processing Conference (EUSIPCO2008), European Association for Signal Processing (EURASIP), Lausanne, Switzerland.


@Misc{EUSIPCO08,
  author = {Javier Cruz and Julien Meynet and Taner Arsan and Jean-Philippe Thiran},
  title = {Fast multi-view face tracking with pose estimation},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/EUSIPCO08.pdf}},
  year = {2008},
  note = {Presented at 16th European Signal Processing Conference (EUSIPCO2008), European Association for Signal Processing (EURASIP), Lausanne, Switzerland}}}

2007

Cruz J., Robin T., Sorci M., Bierlaire M., Thiran J. Modelling Human Perception of Facial Expressions by Discrete Choice Models August 30, 2007. Third Workshop on Discrete Choice Models, Transport and Mobility Laboratory, EPFL, Lausanne, Switzerland.


@Misc{DCA07JAVI,
  author = {Javier Cruz and Thomas Robin and Matteo Sorci and Michel Bierlaire and Jean-Philippe Thiran},
  title = {Modelling Human Perception of Facial Expressions by Discrete Choice Models},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/DCA07JAVI.pdf}},
  year = {2007},
  note = {Presented at Third Workshop on Discrete Choice Models, Transport and Mobility Laboratory, EPFL, Lausanne, Switzerland}}}