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Publications

Publications by CTM

2014

DALM-SVD: ACCELERATED SPARSE CODING THROUGH SINGULAR VALUE DECOMPOSITION OF THE DICTIONARY

Authors
Goncalves, H; Correia, M; Li, X; Sankaranarayanan, A; Tavares, V;

Publication
2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP)

Abstract
Sparse coding techniques have seen an increasing range of applications in recent years, especially in the area of image processing. In particular, sparse coding using l(1)-regularization has been efficiently solved with the Augmented Lagrangian (AL) applied to its dual formulation (DALM). This paper proposes the decomposition of the dictionary matrix in its Singular Value/Vector form in order to simplify and speed-up the implementation of the DALM algorithm. Furthermore, we propose an update rule for the penalty parameter used in AL methods that improves the convergence rate. The SVD of the dictionary matrix is done as a pre-processing step prior to the sparse coding, and thus the method is better suited for applications where the same dictionary is reused for several sparse recovery steps, such as block image processing.

2014

Assessing Cosmetic Results After Breast Conserving Surgery

Authors
Cardoso, MJ; Oliveira, H; Cardoso, J;

Publication
JOURNAL OF SURGICAL ONCOLOGY

Abstract
"Taking less treating better" has been one of the major improvements of breast cancer surgery in the last four decades. The application of this principle translates into equivalent survival of breast cancer conserving treatment (BCT) when compared to mastectomy, with a better cosmetic outcome. While it is relatively easy to evaluate the oncological results of BCT, the cosmetic outcome is more difficult to measure due to the lack of an effective and consensual procedure. The assessment of cosmetic outcome has been mainly subjective, undertaken by a panel of expert observers or/and by patient self-assessment. Unfortunately, the reproducibility of these methods is low. Objective methods have higher values of reproducibility but still lack the inclusion of several features considered by specialists in BCT to be fundamental for cosmetic outcome. The recent addition of volume information obtained with 3D images seems promising. Until now, unfortunately, no method is considered to be the standard of care. This paper revises the history of cosmetic evaluation and guides us into the future aiming at a method that can easily be used and accepted by all, caregivers and caretakers, allowing not only the comparison of results but the improvement of performance. (C) 2014 Wiley Periodicals, Inc.

2014

Classification of Optical Music Symbols based on Combined Neural Network

Authors
Wen, CH; Rebelo, A; Zhang, J; Cardoso, J;

Publication
2014 INTERNATIONAL CONFERENCE ON MECHATRONICS AND CONTROL (ICMC)

Abstract
In this paper, a new method for music symbol classification named Combined Neural Network (CNN) is proposed. Tests are conducted on more than 9000 music symbols from both real and scanned music sheets, which show that the proposed technique offers superior classification capability. At the same time, the performance of the new network is compared with the single Neural Network (NN) classifier using the same music scores. The average classification accuracy increased more than ten percent, reaching 98.82%.

2014

A DEPTH-MAP APPROACH FOR AUTOMATIC MICE BEHAVIOR RECOGNITION

Authors
Monteiro, JP; Oliveira, HP; Aguiar, P; Cardoso, JS;

Publication
2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP)

Abstract
Animal behavior assessment plays an important role in basic and clinical neuroscience. Although assessing the higher functional level of the nervous system is already possible, behavioral tests are extremely complex to design and analyze. Animal's responses are often evaluated manually, making it subjective, extremely time consuming, poorly reproducible and potentially fallible. The main goal of the present work is to evaluate the use of consumer depth cameras, such as the Microsoft's Kinect, for detection of behavioral patterns of mice. The hypothesis is that the depth information, should enable a more feasible and robust method for automatic behavior recognition. Thus, we introduce our depth-map based approach comprising mouse segmentation, body-like per-frame feature extraction and per-frame classification given temporal context, to prove the usability of this methodology.

2014

Context-based Trajectory Descriptor for Human Activity Profiling

Authors
Pereira, EM; Ciobanu, L; Cardoso, JS;

Publication
2014 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN AND CYBERNETICS (SMC)

Abstract
The increasing demand for human activity analysis on surveillance scenarios has been provoking the emerging of new features and concepts that could help to identify the activities of interest. In this paper, we present a context-based descriptor to identify individual profiles. It accounts with a multi-scale histogram representation of position-based and attention-based features that follow a key-point trajectory sampling. The notion of profile is expressed by a new semantic concept introduced as an adjective for action recognition. We also identify a very rich dataset, in terms of intensity and variability of human activity, and extended it by manual annotation to validate the introduced concept of profile and test the descriptor's discriminative power. High rates of recognition were achieved.

2014

3D Reconstruction of Body Parts Using RGB-D Sensors: Challenges from a Biomedical Perspective

Authors
Costa, P; Zolfagharnasab, H; Monteiro, JP; Cardoso, JS; Oliveira, HP;

Publication
Proceedings of the 5th International Conference on 3D Body Scanning Technologies, Lugano, Switzerland, 21-22 October 2014

Abstract

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