18 June 1993 Image quality improvement by pre- and post-processing in DCT coding
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Coding for full-color still-image is standardized internationally by JPEG (Joint Photographic Experts Group). The coding method is used in wide area applications. In many cases, continuous-tone images are accompanied by characters. So improvements of JPEG coding by pre and post processing are investigated in mixed images. In this process, we use sharpening before JPEG coding as a pre-processing, and we use smoothing after JPEG coding as a post- processing. In both pre and post processing, the degree of emphasis is controlled by a weighting factor and the quality is compared between processed and unprocessed images. As a result of this process, it is confirmed that the processed image is better than an unprocessed image in quality.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hiroshi Akitsu, Hiroshi Akitsu, Noboru Kutsuwada, Noboru Kutsuwada, Makoto Omodani, Makoto Omodani, Yasushi Hoshino, Yasushi Hoshino, } "Image quality improvement by pre- and post-processing in DCT coding", Proc. SPIE 1912, Color Hard Copy and Graphic Arts II, (18 June 1993); doi: 10.1117/12.146287; https://doi.org/10.1117/12.146287


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