| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent deterioration in image quality, an increase in data quantity to be embedded in image data and scale-up of a file in embedding optional data into the image data. <P>SOLUTION: A quantization representative value R1 (X) of a division result value D(X)/Q1(X) of a DCT coefficient D(X) of an original EOB is changed to a value R2(X) most approximate to the division result value D(X)/Q1(X) out of -1 and 1, as a data finish marker. Since the data finish marker is at a low-frequency side by one coefficient position of a new EOB, a decoder side can discriminate an insertion bit "0" from a zero quantization representative value sequence under EOB (end of block) by detecting the data finish marker in sequentially decoding DCT coefficients from the low-frequency side. The new EOB advances by one coefficient position to the high-frequency side from the original EOB, however, the EOB itself never disappears. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
