In this paper, two circular shape extraction methods based on C A M (Content Addressable M e m o y ) concept are proposed. The first method based on Hough Transform uses only the gradient amplitude infonnation, while the second uses in addition preselected gradient direction to estimate the center coordinates of the circle and then apply the H T circle extraction to extract i t 's mdius. The ad...

Optic nerve head is part of the retina where ganglion cell axons exit the eye to form the optic nerve. Glaucomatous changes related to loss of the nerve fibers decrease the neuroretinal rim and expand the area and volume of the cup. Therefore optic nerve head evaluation is important for early diagnosis of glaucoma. This study implements the detection of the optic nerve head in retinal fundus im...

An algorithm is presented to compute smoothed local symmetries on a MIMD architecture. Based on Brady and Scott's Connection Machine algorithm, it is adapted to reduce the synchronisation and communication overheads involved. Using an evidence accumulation approach similar to the Hough transform for circle detection, this algorithm can compute both local and rotational symmetries simultaneously...

This Paper presents two automatic segmentation methods to locate nuclei in cytological images. The analysis includes the watershed algorithm, active contouring. One can also find here a description of image enhancement, Hough transform for circle detection and automatic nuclei localization mechanism used in this approach. Preliminary experimental results collected present the quality of the met...

This paper presents an alternative for a fast computation of the Hough transform by taking advantage of commodity graphics processors that provide a unique combination of low cost and high performance platforms for this sort of algorithms. Optimizations focus on the features of a GPU rasterizer to evaluate, in hardware, the entire spectrum of votes for circle candidates from a small number of k...

This paper proposes a vision-based pedestrian detection in crowded situations based on a single camera. The main idea behind our work is to fuse multiple cues so that the major challenges, such as occlusion and complex background facing in the topic of crowd detection can be successfully overcome. Based on the assumption that human heads are visible, circle Hough transform (CHT) is applied to d...

The Circle Hough Transform (CHT) has become a common method for circle detection in numerous image processing applications. Various modifications to the basic CHT operation have been suggested which include: the inclusion of edge orientation, simultaneous consideration of a range of circle radii, use of a complex accumulator array with the phase proportional to the log of radius, and the implem...

In this paper, the reassigned local polynomial periodogram along the frequency direction (RfLPP) is shown to be able to perfectly localize the chirp signal. Due to this property, the RfLPP is combined with the Hough transform for chirp signal detection in the parameter domain. Simulations of the RfLPP-Hough transform are given for chirp signal detection in white Gaussian noise and impulsive noi...

The basic principle of photogrammetry is mature and widely used in engineering. For gantry cranes, the base which usually a cylinder, measurement center cylinder cross section difficult, but its coordinates have an important impact on safety evaluation cranes. Aiming at problem measuring circle, optimization method fitting circle based Hough transform proposed. In this algorithm, effect image p...