[GEM-dev] [pix_video]: issue with swapped colors

[Mathieu Bouchard]

On Wed, 9 May 2007, IOhannes m zmoelnig wrote:

> another way (less efficient, and wrong if matju is right):
> videoV4L.cpp:173: add "m_image.image.swapRedBlue();"

In my last mail, I didn't claim that the problem was surely (U,V) 
swapping, I said that it was a possibility, but now I think I should have 
said that it's almost certainly that.

It's because, in the encoder of the camera, U and V are necessarily 
encoded as properly scaled B-Y and R-Y anyway, because else it would be a 
blatant bug, and I can't imagine a camera setting that would allow for 
violating the definitions of U and V to make them confuse R and B. 
(although... now that I think of it, I'd really enjoy a camera that allows 
me to set the contrast separately on Y, U and V.)

Therefore, U and V come as correct through the cable and the driver and/or 
the GEM object confuses them.

makes sense?

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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal QC Canada