Selective Reduction Method of the Mosquito Noise in JPEG Decoded Image
Tsutomu Shohdohji, Yohsuke Sasaki, Yasushi Hoshino · 2002
Abstract The JPEG (Joint Photographic Experts Group) compression algorithm is possible to decode an image effectively, by considering the visual characteristic of human beings. However, the mosquito noise generates in the block, when a compression rate is high. It is lost to not only the mosquito noise but also important image information which constitutes an image, when the usual noise reduction filter was applied for an image including the mosquito noise. As the result, image quality falls off. Then, our proposed method is possible to restrain degradation of image quality, while reducing noise, by changing weight of filtering every block. We confirmed that our proposed method was effective by the computer experiment. Introduction JPEG 2) is one of the most famous coding methods that are used widely to compress a digital image. The lossless coding method and lossy coding method are included to the JPEG compression system. Lossy coding method, one of the JPEG base line algorithms that used DCT (discrete cosine transform), is able to materialize high compressibility is used generally. As for the image by an impassable reverse method high compression is obtained dramatically. On the other hand, the deterioration and various noise of the image quality sometimes occur. There is block noise (false contour is included) and mosquito noise (it is able to consider as kind of block noise), in the main noise that occurs with JPEG coded method. There exists