发明名称 ENHANCING COMPRESSION WHILE TRANSCODING JPEG IMAGES
摘要 Further compression of data allowing economical storage of data for extended periods of time in high-speed access memory is performed in reduced time by performing further compression during transcoding in the transform domain and without restoring image data to its original image data form. The reduction in processing time is achieved by exploiting the large number of zero-valued quantization transform coefficients and not changing quantized transform coefficients at zig-zag scan positions where non-zero coefficients are rare during range reduction of the entropy decoded quantized transformed data. The range can be restored by computation or estimation of an altered quantization table which is stored with the further compressed quantization values. Further advantages accrue from use of JPEG packed format for the data during transcoding.
申请公布号 WO2004032022(A2) 申请公布日期 2004.04.15
申请号 WO2003GB03947 申请日期 2003.09.12
申请人 IBM;IBM UK 发明人 MITCHELL JOAN;PRAKASH RAVI
分类号 G06T9/00 主分类号 G06T9/00
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