Replacing/Extracting Regions
ECM can be used to address individual blocks in the compressed stream.
In combination with the DC Map, portions of the image can be readily identified.
Stitching can be resolved using simple non-linear (sigma) filters.
Average background luminance can be used to replace regions.
Methods to process compressed data can also be found in “Processing JPEG-Compressed Images” Proc. of ICIP 97.