| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To segment an image only for a part required for data output without passing through processing for decompressing the whole of a compressed recorded image. <P>SOLUTION: A block for one unit is identified by counting DCT (Discrete Cosine Transform) coefficients for 64 pieces from a low-frequency side to a high-frequency side in a zigzag order (S10). Whether or not the DCT coefficients for 64 pieces (from a DCT coefficient of the lowest frequency to an EOB when the DCT coefficients are closed at the EOB) identified as the block for one unit is included in a coating block group Zcov is determined (S11). In the case of Yes, frequency components of DCT coefficients to which IDCT (Inverse Discrete Cosine Transform) should be applied based on target resolution are determined for the DCT coefficients for 64 pieces (or the DCT coefficients from the DCT coefficient of the lowest frequency to the EOB) determined to be included in the coating block group Zcov, and inverse quantization and the IDCT are applied only to the DCT coefficients of the determined frequency components to obtain thinned image data (S12). <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
