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Author | Patricia Marquez; Debora Gil ; Aura Hernandez-Sabate | ||||
Title | Error Analysis for Lucas-Kanade Based Schemes | Type | Conference Article | ||
Year | 2012 | Publication | 9th International Conference on Image Analysis and Recognition | Abbreviated Journal | |
Volume | 7324 | Issue | I | Pages | 184-191 |
Keywords | Optical flow, Confidence measure, Lucas-Kanade, Cardiac Magnetic Resonance | ||||
Abstract | Optical flow is a valuable tool for motion analysis in medical imaging sequences. A reliable application requires determining the accuracy of the computed optical flow. This is a main challenge given the absence of ground truth in medical sequences. This paper presents an error analysis of Lucas-Kanade schemes in terms of intrinsic design errors and numerical stability of the algorithm. Our analysis provides a confidence measure that is naturally correlated to the accuracy of the flow field. Our experiments show the higher predictive value of our confidence measure compared to existing measures. | ||||
Address | Aveiro, Portugal | ||||
Corporate Author | Thesis | ||||
Publisher | Springer-Verlag Berlin Heidelberg | Place of Publication | Editor | ||
Language | english | Summary Language | Original Title | ||
Series Editor | Campilho, Aurélio and Kamel, Mohamed | Series Title | Lecture Notes in Computer Science | Abbreviated Series Title | LNCS |
Series Volume | Series Issue | Edition | |||
ISSN | 0302-9743 | ISBN | 978-3-642-31294-6 | Medium | |
Area | Expedition | Conference | ICIAR | ||
Notes | IAM | Approved | no | ||
Call Number | IAM @ iam @ MGH2012a | Serial | 1899 | ||
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Author | David Geronimo; Frederic Lerasle; Antonio Lopez | ||||
Title | State-driven particle filter for multi-person tracking | Type | Conference Article | ||
Year | 2012 | Publication | 11th International Conference on Advanced Concepts for Intelligent Vision Systems | Abbreviated Journal | |
Volume | 7517 | Issue | Pages | 467-478 | |
Keywords | human tracking | ||||
Abstract | Multi-person tracking can be exploited in applications such as driver assistance, surveillance, multimedia and human-robot interaction. With the help of human detectors, particle filters offer a robust method able to filter noisy detections and provide temporal coherence. However, some traditional problems such as occlusions with other targets or the scene, temporal drifting or even the lost targets detection are rarely considered, making the systems performance decrease. Some authors propose to overcome these problems using heuristics not explained
and formalized in the papers, for instance by defining exceptions to the model updating depending on tracks overlapping. In this paper we propose to formalize these events by the use of a state-graph, defining the current state of the track (e.g., potential , tracked, occluded or lost) and the transitions between states in an explicit way. This approach has the advantage of linking track actions such as the online underlying models updating, which gives flexibility to the system. It provides an explicit representation to adapt the multiple parallel trackers depending on the context, i.e., each track can make use of a specific filtering strategy, dynamic model, number of particles, etc. depending on its state. We implement this technique in a single-camera multi-person tracker and test it in public video sequences. |
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Address | Brno, Chzech Republic | ||||
Corporate Author | Thesis | ||||
Publisher | Springer | Place of Publication | Heidelberg | Editor | J. Blanc-Talon et al. |
Language | English | Summary Language | Original Title | ||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Medium | |||
Area | Expedition | Conference | ACIVS | ||
Notes | ADAS | Approved | yes | ||
Call Number | GLL2012; ADAS @ adas @ gll2012a | Serial | 1990 | ||
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Author | Yainuvis Socarras; David Vazquez; Antonio Lopez; David Geronimo; Theo Gevers | ||||
Title | Improving HOG with Image Segmentation: Application to Human Detection | Type | Conference Article | ||
Year | 2012 | Publication | 11th International Conference on Advanced Concepts for Intelligent Vision Systems | Abbreviated Journal | |
Volume | 7517 | Issue | Pages | 178-189 | |
Keywords | Segmentation; Pedestrian Detection | ||||
Abstract | In this paper we improve the histogram of oriented gradients (HOG), a core descriptor of state-of-the-art object detection, by the use of higher-level information coming from image segmentation. The idea is to re-weight the descriptor while computing it without increasing its size. The benefits of the proposal are two-fold: (i) to improve the performance of the detector by enriching the descriptor information and (ii) take advantage of the information of image segmentation, which in fact is likely to be used in other stages of the detection system such as candidate generation or refinement.
We test our technique in the INRIA person dataset, which was originally developed to test HOG, embedding it in a human detection system. The well-known segmentation method, mean-shift (from smaller to larger super-pixels), and different methods to re-weight the original descriptor (constant, region-luminance, color or texture-dependent) has been evaluated. We achieve performance improvements of 4:47% in detection rate through the use of differences of color between contour pixel neighborhoods as re-weighting function. |
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Address | Brno, Czech Republic | ||||
Corporate Author | Thesis | ||||
Publisher | Springer Berlin Heidelberg | Place of Publication | Editor | J. Blanc-Talon et al. | |
Language | English | Summary Language | Original Title | ||
Series Editor | Series Title | Abbreviated Series Title | LNCS | ||
Series Volume | Series Issue | Edition | |||
ISSN | 0302-9743 | ISBN | 978-3-642-33139-8 | Medium | |
Area | Expedition | Conference | ACIVS | ||
Notes | ADAS;ISE | Approved | no | ||
Call Number | ADAS @ adas @ SLV2012 | Serial | 1980 | ||
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Author | David Vazquez; Jiaolong Xu; Sebastian Ramos; Antonio Lopez; Daniel Ponsa | ||||
Title | Weakly Supervised Automatic Annotation of Pedestrian Bounding Boxes | Type | Conference Article | ||
Year | 2013 | Publication | CVPR Workshop on Ground Truth – What is a good dataset? | Abbreviated Journal | |
Volume | Issue | Pages | 706 - 711 | ||
Keywords | Pedestrian Detection; Domain Adaptation | ||||
Abstract | Among the components of a pedestrian detector, its trained pedestrian classifier is crucial for achieving the desired performance. The initial task of the training process consists in collecting samples of pedestrians and background, which involves tiresome manual annotation of pedestrian bounding boxes (BBs). Thus, recent works have assessed the use of automatically collected samples from photo-realistic virtual worlds. However, learning from virtual-world samples and testing in real-world images may suffer the dataset shift problem. Accordingly, in this paper we assess an strategy to collect samples from the real world and retrain with them, thus avoiding the dataset shift, but in such a way that no BBs of real-world pedestrians have to be provided. In particular, we train a pedestrian classifier based on virtual-world samples (no human annotation required). Then, using such a classifier we collect pedestrian samples from real-world images by detection. After, a human oracle rejects the false detections efficiently (weak annotation). Finally, a new classifier is trained with the accepted detections. We show that this classifier is competitive with respect to the counterpart trained with samples collected by manually annotating hundreds of pedestrian BBs. | ||||
Address | Portland; Oregon; June 2013 | ||||
Corporate Author | Thesis | ||||
Publisher | IEEE | Place of Publication | Editor | ||
Language | English | Summary Language | English | Original Title | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Medium | |||
Area | Expedition | Conference | CVPRW | ||
Notes | ADAS; 600.054; 600.057; 601.217 | Approved | no | ||
Call Number | ADAS @ adas @ VXR2013a | Serial | 2219 | ||
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Author | Jiaolong Xu; David Vazquez; Sebastian Ramos; Antonio Lopez; Daniel Ponsa | ||||
Title | Adapting a Pedestrian Detector by Boosting LDA Exemplar Classifiers | Type | Conference Article | ||
Year | 2013 | Publication | CVPR Workshop on Ground Truth – What is a good dataset? | Abbreviated Journal | |
Volume | Issue | Pages | 688 - 693 | ||
Keywords | Pedestrian Detection; Domain Adaptation | ||||
Abstract | Training vision-based pedestrian detectors using synthetic datasets (virtual world) is a useful technique to collect automatically the training examples with their pixel-wise ground truth. However, as it is often the case, these detectors must operate in real-world images, experiencing a significant drop of their performance. In fact, this effect also occurs among different real-world datasets, i.e. detectors' accuracy drops when the training data (source domain) and the application scenario (target domain) have inherent differences. Therefore, in order to avoid this problem, it is required to adapt the detector trained with synthetic data to operate in the real-world scenario. In this paper, we propose a domain adaptation approach based on boosting LDA exemplar classifiers from both virtual and real worlds. We evaluate our proposal on multiple real-world pedestrian detection datasets. The results show that our method can efficiently adapt the exemplar classifiers from virtual to real world, avoiding drops in average precision over the 15%. | ||||
Address | Portland; oregon; June 2013 | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Summary Language | English | Original Title | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Medium | |||
Area | Expedition | Conference | CVPRW | ||
Notes | ADAS; 600.054; 600.057; 601.217 | Approved | yes | ||
Call Number | XVR2013; ADAS @ adas @ xvr2013a | Serial | 2220 | ||
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Author | Sergio Vera; Debora Gil; Antonio Lopez; Miguel Angel Gonzalez Ballester | ||||
Title | Multilocal Creaseness Measure | Type | Journal | ||
Year | 2012 | Publication | The Insight Journal | Abbreviated Journal | IJ |
Volume | Issue | Pages | |||
Keywords | Ridges, Valley, Creaseness, Structure Tensor, Skeleton, | ||||
Abstract | This document describes the implementation using the Insight Toolkit of an algorithm for detecting creases (ridges and valleys) in N-dimensional images, based on the Local Structure Tensor of the image. In addition to the filter used to calculate the creaseness image, a filter for the computation of the structure tensor is also included in this submission. | ||||
Address | |||||
Corporate Author | Alma IT Systems | Thesis | |||
Publisher | Place of Publication | Editor | |||
Language | english | Summary Language | english | Original Title | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Medium | |||
Area | Expedition | Conference | |||
Notes | IAM;ADAS; | Approved | no | ||
Call Number | IAM @ iam @ VGL2012 | Serial | 1840 | ||
Permanent link to this record | |||||
Author | Albert Andaluz | ||||
Title | Harmonic Phase Flow: User's guide | Type | Manual | ||
Year | 2012 | Publication | CVC | Abbreviated Journal | |
Volume | Issue | Pages | |||
Keywords | |||||
Abstract | HPF is a plugin for the computation of clinical scores under Osirix.
This manual provides a basic guide for experienced clinical staff. Chapter 1 provides the theoretical background in which this plugin is based. Next, in chapter 2 we provide basic instructions for installing and uninstalling this plugin. chapter 3we shows a step-by-step scenario to compute clinical scores from tagged-MRI images with HPF. Finally, in chapter 4 we provide a quick guide for plugin developers |
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Address | Bellaterra, Barcelona (Spain) | ||||
Corporate Author | Computer Vision Center | Thesis | |||
Publisher | CVC | Place of Publication | Barcelona | Editor | |
Language | english | Summary Language | english | Original Title | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Medium | |||
Area | Expedition | Conference | |||
Notes | IAM | Approved | no | ||
Call Number | IAM @ iam @ And2012 | Serial | 1863 | ||
Permanent link to this record | |||||
Author | Carles Sanchez | ||||
Title | Tracheal ring detection in bronchoscopy | Type | Report | ||
Year | 2011 | Publication | CVC Technical Report | Abbreviated Journal | |
Volume | 168 | Issue | Pages | ||
Keywords | Bronchoscopy, tracheal ring, segmentation | ||||
Abstract | Endoscopy is the process in which a camera is introduced inside a human.
Given that endoscopy provides realistic images (in contrast to other modalities) and allows non-invase minimal intervention procedures (which can aid in diagnosis and surgical interventions), its use has spreaded during last decades. In this project we will focus on bronchoscopic procedures, during which the camera is introduced through the trachea in order to have a diagnostic of the patient. The diagnostic interventions are focused on: degree of stenosis (reduction in tracheal area), prosthesis or early diagnosis of tumors. In the first case, assessment of the luminal area and the calculation of the diameters of the tracheal rings are required. A main limitation is that all the process is done by hand, which means that the doctor takes all the measurements and decisions just by looking at the screen. As far as we know there is no computational framework for helping the doctors in the diagnosis. This project will consist of analysing bronchoscopic videos in order to extract useful information for the diagnostic of the degree of stenosis. In particular we will focus on segmentation of the tracheal rings. As a result of this project several strategies (for detecting tracheal rings) had been implemented in order to compare their performance. |
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Address | |||||
Corporate Author | Thesis | Master's thesis | |||
Publisher | Place of Publication | Editor | Debora Gil, F.Javier Sanchez | ||
Language | english | Summary Language | english | Original Title | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Medium | |||
Area | Expedition | Conference | |||
Notes | IAM;MV | Approved | no | ||
Call Number | IAM @ iam @ San2011 | Serial | 1841 | ||
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