bluesphere
Sat Dec 30 16:50:04 CST 2006
The lib itself was @
http://www.pocketpcdn.com/
Even though the formula is reversible when you
convert from RGB to YUV you discard samples
and when you convert from YUV to RGB the
missing samples are interpolated.
Happy new year, Remi
"Remi de Gravelaine" <gravelaine at aton dash sys dot fr> wrote in message
news:ejA6WRDLHHA.4384@TK2MSFTNGP03.phx.gbl...
> > Try JpegLib by the Independent JPEG Group. Chances are
> > the Lib accepts the YUV format.
>
> It actually works after minor adaptation to Windows CE, and takes as input
> "video lines" in the YUV format.
> I agree with you for the potential loss of quality caused by the "YUV
4:2:2
> to RGB back to YUV" conversion, although it can theoretically be harmless:
I
> am not a mathematician but the formulaes used to convert to and from the
two
> formats look rather reversible. The main picture degradation (half the
> colors going to nirvana) comes from the initial "samples to 4:2:2"
> conversion. IMO, the effects of extra conversions should be the loss of a
> few other colors close to the white and black areas.
> Thus, if quality is not an issue, maybe is it simpler for the OP to make
the
> first conversion and to let MS code perform the second one.
> Also consider that if some on-screen display of the captured data is also
> needed, maybe RGB format will be needed too, e.g. if a
DirectDraw-compliant
> video driver is not available.
>
> Remi
>
>