Reply by destiny_nz June 28, 20072007-06-28
Hi guys,

For the JPEG encoding processes, after the DCT and quantization of each
8*8 blocks, two Zig-Zag encoding modes can be used. One is sequential
encoding and another one is progressive encoding. While sequential
encoding encodes coefficients of a single block at a time (in a zig-zag
manner), progressive encoding encodes similar-positioned coefficients of
all blocks in one go, followed by the next positioned coefficients of all
blocks, and so on. 

My question is, would those two different encoding modes produce the same
coefficient matrix? The point that I am not quite sure about is that, for
example a 256*256 image. When I doing the progressive encoding, I encode
the DC coefficients from each 8*8 block first, then do I concatenate these
1024 DC coefficients together or just keep them in their original blocks
and move onto the next positioned AC coefficient? 

Thank you very much