关键词: 压缩域边缘检测, DCT, JPEG

Abstract:

Compressed-domain image analysis and process have been an active area in the fields of multimedia research. A fast JPEG image edge detection method based on DCT compressed domain was presented, which computes the edge points directly from none-zero DCT coefficients without full decompression, so that a lot of computational cost was saved. In addition, edge image with different accuracy to meet different demands could be obtained progressively by this method. Compared with the traditional pixel domain based edge detection algorithms such as Laplacian Operator, Canny Operator, Sobel Operator and so on, the proposed method calculated the pixel gradient directly from some important DCT coefficients other than original pixel values. Further more, some approaches to reduce the computational cost were used in this paper. The method could be used in the long- range object recognition or Web-based JPEG image retrieval.

Key words: compressed domain edge detection, DCT, JPEG