This paper presents a novel hierarchical shape description scheme based on propagating the gradient of the image. The propagated gradient eld collides at centers of con-vex/concave shape components, which can be detected as points of high directional disparity. A novel vectorial disparity measure called Cancelation Energy is used to measure this collision of the gradient eld, and local maxima o...

This paper presents a novel hierarchical shape description scheme based on propagating the image gradient radially This radial propagation is equivalent to a vectorial convolution with sector elements The propagated gradient eld collides at centers of convex concave shape components which can be detected as points of high directional disparity A novel vectorial disparity measure called Cancella...

One important feature of Bayesian Ying–Yang (BYY) harmony learning is that model selection can be made automatically during parametric learning. In this paper, BYY harmony learning with a bi-directional architecture is studied for Gaussian mixture modelling via a gradient learning rule. It has been demonstrated by simulation experiments that the number of Gaussians can be determined automatical...

Despite their shortcomings, gradient and second derivative operators remain popular as edge detectors because human beings usually do not show strong directional preferences when detecting edges or boundaries. However, in a colour image an edge can be given not only if the respective brightness values of two neighbouring pixels are significantly different, but also if their chromatic components...

A new method for feature extraction and recognition, namely the fuzzy bidirectional weighted sum criterion (FBWSC) is proposed in this paper. FBWSC defines the row directional fuzzy image optimal image projection matrix. Subsequently, each sample in the original training sample set is transformed using the row directional optimal image projection matrix, and the row directional feature training...

In this thesis, the limitations of the conventional morphological gradient (MG) as an edge detector are theoretically analyzed, and three new methods with improved performance are developed. The new methods are analyzed theoretically and demonstrated with both synthetic and real image data. The basic issues regarding edge detection, linear and nonlinear filtering, especially in morphological fi...

Active contours or snakes are an effective edge-based method in segmenting an object of interest. However, the segmented boundary of a moving object in one video frame may lie far from the same moving object in the next frame due to its rapid motion, causing the snake to converge on the wrong edges. To guide the snake toward the appropriate edges, we have added gradient-directional information ...