tailieunhanh - Báo cáo hóa học: " Research Article Image Segmentation Method Using Thresholds Automatically Determined from Picture Contents"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Image Segmentation Method Using Thresholds Automatically Determined from Picture Contents | Hindawi Publishing Corporation EURASIP Journal on Image and Video Processing Volume 2009 Article ID 140492 15 pages doi 2009 140492 Research Article Image Segmentation Method Using Thresholds Automatically Determined from Picture Contents Yuan Been Chen1 2 and Oscal . Chen1 1 Department of Electrical Engineering National Chung Cheng University Chia-Yi 62102 Taiwan 2 Department of Electronic Engineering Chienkuo Technology University Changhua City 500 Taiwan Correspondence should be addressed to Yuan Been Chen ybchen@ Received 1 June 2008 Revised 5 November 2008 Accepted 28 January 2009 Recommended by Jean-Philippe Thiran Image segmentation has become an indispensable task in many image and video applications. This work develops an image segmentation method based on the modified edge-following scheme where different thresholds are automatically determined according to areas with varied contents in a picture thus yielding suitable segmentation results in different areas. First the iterative threshold selection technique is modified to calculate the initial-point threshold of the whole image or a particular block. Second the quad-tree decomposition that starts from the whole image employs gray-level gradient characteristics of the currently-processed block to decide further decomposition or not. After the quad-tree decomposition the initial-point threshold in each decomposed block is adopted to determine initial points. Additionally the contour threshold is determined based on the histogram of gradients in each decomposed block. Particularly contour thresholds could eliminate inappropriate contours to increase the accuracy of the search and minimize the required searching time. Finally the edge-following method is modified and then conducted based on initial points and contour thresholds to find contours precisely and rapidly. By using the Berkeley segmentation data set with realistic images the proposed method is demonstrated to take the least .