This thesis explores component trees, hierarchical structures from Mathematical Mor-phology, and their application to image retrieval and related tasks. The distinct com-ponent trees are analyzed and a novel classification into two superclasses is proposed,as well as a contribution to indexing and representation of the hierarchies using den-drograms. The first contribution t...

Face recognition is important in human identification. The biological recognition technique acts as a good method and broad applications in security areas. This work presents a method to improve the face recognition accuracy using a combination of Principal Component Analysis (PCA), and Wavelet Transform. Wavelet Transform is used to decompose the input image with different levels and rearrange...

Speed Up Robust Feature (SURF) and Local Contour Sequence(LCS) are methods used for feature extraction techniques for dynamic gesture recognition. A problem presented by these techniques is the large amount of data in the output vector which difficult the classification task. This paper presents a novel method for dimensionality reduction of the features extracted by SURF and LCS, called Convex...

In this paper, we present a novel image mosaicking method that is based on Speeded-Up Robust Features (SURF) of line segments, aiming to achieve robustness to incident scaling, rotation, change in illumination, and significant affine distortion between images in a panoramic series. Our method involves 1) using a SURF detection operator to locate feature points; 2) rough matching using SURF feat...

In this paper, we compare the performance of matching algorithms in terms of efficiency, robustness, and computation time. Our evaluation uses as criterion, for efficiency and robustness, number of inliers and is carried out for different video sequences with abrupt motions (translation, rotation, combined). We compare SIFT, SURF, cross-correlation with Harris detector, and cross-correlation wi...

The use of indicators for evaluating the microbiological quality of the marine surf-zone water is a worldwide practice. It is important that the indicator used, is the most relevant in relation to bathers’ health. It must be easy to detect and it must be cost effective. This paper reports the comparison between the occurrence of faecal coliforms and Escherichia coli in the marine surf-zone. Bot...

This paper presents the application of the open source non-hydrostatic wave-flow model SWASH to propagation of irregular waves in a barred surf zone, and the model results are discussed by comparing against an extensive laboratory data set. This study focus not only on wave transformation in the surf zone, but also on the numerical prediction of undertow and vertical distribution of turbulence ...

Practical use of SURF feature points in large-scale indexing and retrieval engines requires an efficient means for storing and decoding these features. This paper investigates several methods for compression and storage of SURF feature points, considering both storage consumption and disk-read efficiency. We compare each scheme with a baseline plaintext encoding scheme as used by many existing ...