| 摘要 |
A compressed-domain-based algorithm reduces a source image to a given target size using a combination of downscaling, cropping, and region-of-interest identification. The source image is partitioned into a plurality of macroblocks, each macroblock containing a plurality of chrominance and luminance blocks, each chrominance block and each luminance block containing a DC coefficient and AC coefficients. To each macroblock, a first rule is applied based on values of the DC coefficient of the chrominance blocks in that macroblock to identify a particular type of texture in the image. Also to each macroblock, a second rule is applied based on select values of the AC coefficient of luminance blocks in that macroblock to identify edges in the image. The macroblocks within the image are then searched to find an area containing an area of interest based on the results of applying the first and second rules.
|
