Reduction of Blocking Artifacts In JPEG Compressed Image

In JPEG (DCT based) compresses image data by representing the original image with a small number of transform coefficients. It exploits the fact that for typical images a large amount of signal energy is concentrated in a small number of coefficients. The goal of DCT transform coding is to minimize the number of retained transform coefficients while keeping distortion at an acceptable level.In JPEG, it is done in 8X8 non overlapping blocks. It divides an image into blocks of equal size and processes each block independently. Block processing allows the coder to adapt to the local image statistics, exploit the correlation present among neighboring image pixels, and to reduce computational and storage requirements. One of the most degradation of the block transform coding is the blocking artifact. These artifacts appear as a regular pattern of visible block boundaries. This degradation is a direct result of the coarse quantization of the coefficients and the independent processing of the blocks which does not take into account the existing correlations among adjacent block pixels. In this paper attempt is being made to reduce the blocking artifact introduced by the Block DCT Transform in JPEG.