JPEG encoding

[Constantin Kaplinsky]

Hello Jonathan,

>>>>> "JM" == Jonathan Morton <chromi "at" cyberspace.org> writes:

>> That would be Tight VNC. Detailed explanation of encoding probably
>> best left to Const Kaplinsky...

JM> Looking at the TightVNC source, it seems that JPEG is implemented
JM> as a subencoding of TightVNC, rather than as something separate. 
JM> Still, it may be usable for what I have in mind.

Yes, it's implemented as a subencoding of Tight encoding. JPEG is used
only for color-rich areas where it does better work than zlib-like
compression. But for indexed colors, lossless Tight encoder does
better work. Thus JPEG complements Tight encoding pretty well.

JM> More detail here... I have a tiny VNC server embedded in a
JM> modified version of the XawTV webcam utility. At the moment it
JM> makes no attempt to compress the data, other than breaking it down
JM> into tiles, sending the most-changed ones first, and throttling
JM> back when changes between frames are insignificant. It works
JM> fairly well over broadband connections, but implementing
JM> compression on each tile would further reduce bandwidth use and
JM> possibly make it tolerable over analogue modems.

If the source of image is webcam, I think JPEG might be a good
choice.

-- 
With Best Wishes,
Constantin
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