@mastersthesis {xTella, title = {Contextless Object Recognition with Shape-enriched SIFT and Bags of Features}, year = {2014}, abstract = {
Final thesis slides (1) from Xavi Gir{\'o}

Advisors:\ Xavier Gir{\'o}-i-Nieto\ (UPC) and Matthias Zeppelzauer\ (TU Wien)

Degree: Telecommunications Engineering (5 years) at\ Telecom BCN-ETSETB\ (UPC)

Currently, there are highly competitive results in the field of object recognition based on the aggregation of point-based features. The aggregation process, typically with an average or max-pooling of the features generates a single vector that represents the image or region that contains the object.

The aggregated point-based features typically describe the texture around the points with descriptors such as SIFT. These descriptors present limitations for wired and textureless objects. A possible solution is the addition of shape-based information. Shape descriptors have been previously used to encode shape information and thus, recognise those types of objects. But generally an alignment step is required in order to match every point from one shape to other ones. The computational cost of the similarity assessment is high.

We purpose to enrich location and texture-based features with shape-based ones. Two main architectures are explored: On the one side, to enrich the SIFT descriptors with shape information before they are aggregated. On the other side, to create the standard Bag of Words histogram and concatenate a shape histogram, classifying them as a single vector.

We evaluate the proposed techniques and the novel features on the Caltech-101 dataset.

Results show that shape features increase the final performance. Our extension of the Bag of Words with a shape-based histogram(BoW+S) results in better performance. However, for a high number of shape features, BoW+S and enriched SIFT architectures tend to converge.

Final grade: A with honors (10/10)

}, keywords = {Bag of Words, Interest Points, object candidates, Object detection, segmentation, shape coding, SIFT, textureless objects, wired objects.}, url = {http://hdl.handle.net/2099.1/22390}, author = {Tella, Marcel}, editor = {Zeppelzauer, Matthias and Xavier Gir{\'o}-i-Nieto} } @conference {cVentura13a, title = {UPC at MediaEval 2013 Hyperlinking Task}, booktitle = {MediaEval 2013 Workshop}, year = {2013}, month = {10/2013}, publisher = {CEUR Workshop Proceedings Vol-1043}, organization = {CEUR Workshop Proceedings Vol-1043}, address = {Barcelona, Catalonia}, abstract = {

These working notes paper present the contribution of the UPC team to the Hyperlinking sub-task of the Search and Hyperlinking Task in MediaEval 2013. Our contribution explores the potential of a solution based only on visual cues.

In particular, every automatically generated shot is represented by a keyframe. The linking between video segments is based on the visual similarity of the keyframes they contain. Visual similarity is assessed with the intersection of bag of features histograms generated with the SURF descriptor.

Xavier Gir{\'o}, "UPC at MediaEval Hyperlinking 2013" from Xavi Gir{\'o}

Presentation on MediaEval Search \& Linking task 2013 from Netherlands Institute for Sound and Vision, University of Twente
}, keywords = {Benchmark, Hyperlinking, Video Collections}, url = {http://ceur-ws.org/Vol-1043/mediaeval2013_submission_35.pdf}, author = {Ventura, C. and Tella, Marcel and Xavier Gir{\'o}-i-Nieto} } @mastersthesis {xTella11, title = {Interactive Image Processing demonstrations for the web}, year = {2011}, abstract = {

This diploma thesis aims to provide a framework for developing web applications for ImagePlus, the software develpment platform in C++ of the Image Processing Group of the Technical University of Catalonia (UPC). These web applications are to demonstrate the functionality of the image processing algorithms to any visitor to the group website. Developers are also benefited from this graphical user interface because they can easily create Graphical User Interfaces (GUIs) for the processing algorithms

Interactive Image Processing Demos for the Web from Xavi Gir{\'o}
}, keywords = {c++, demo, image processing, web}, url = {http://hdl.handle.net/2099.1/13540}, author = {Tella, Marcel}, editor = {Xavier Gir{\'o}-i-Nieto} }