Extending RD-OPT with Global Thresholding for JPEG Optimization
نویسندگان
چکیده
In this paper, the RD-OPT algorithm for optimizing Discrete Cosine Transform quantization tables RL95] is extended to incorporate global thresholding. Performance gains are possible by zeroing oo some DCT coeecients in DCT-based image compression. We describe a global thresholding scheme, in which the zeroing thresholds for coeecients can be arbitrarily diierent from those determined by the quantization table. Unlike local thresholding CR95], the zeroing decisions are not made separately for each image block. This simpliies the use of thresholding, is easier to optimize and is almost as eeective as local thresholding.
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