Contour extraction is one of the typical problems in image processing and computer vision. Contour grouping

which is a contour extraction technique based on perceptual organization

shows promising development trend. This paper addresses the research on contour organization. First

it puts forward the relationship between contour extraction and perceptual organization. Second

a comprehensive summary on related research work is given. Then their characteristics and shortcomings are analyzed. At last

further research directions are suggested.