关键词: 梯度自适应预测器, 梯度边缘检测, 多方向梯度边缘检测预测器, 大津算法, 并行技术, 细化

Abstract: By using Gradient Adjusted Predictor (GAP) and Gradient Edge Detection (GED) predictors of lossless image encoding for reference, with an improved one, a new image edge detection algorithm of the dynamic threshold control based on Multidirectional Gradient Edge Detection Predictor (MGEDP) template was proposed. The image was cut into four equal parts, and these parts would be executed simultaneously by MGEDP template in different direction of four opposite ways to calculate the error values by the parallel technology. From these feedback values, the algorithm created error image, calculated the threshold values by Otsu algorithm, classified the edges of error image, thinned the edges, and composed the last edge image. The experimental results show that the algorithm using parallel technology not only decreases the time complexity, but also gets the clearer edges, more details, and better visual image.

Key words: Gradient Adjusted Predictor (GAP), Gradient Edge Detection (GED), Multidirectional Gradient Edge Detection Predictor (MGEDP), Otsu algorithm, parallel technology, thinning