[PD] Capturing images from a DVcam / webcam

[julien.breval at tremplin-utc.net]

Selon chris clepper <cgc at humboldtblvd.com>:
> Again - what platform are you trying this under?  Video capture is 
> platform dependent.

Windows, Linux

> Also, things like scaling will most likely not be done in hardware so 
> decreasing the size of the incoming image will almost always also 
> decrease performance!  Take DV for example, it should always be 
> 720x480/576 in every situation since the various capture APIs will do 
> software resizing of the DV stream, and I can assure you that most of 
> them don't do this in the most efficient way.  If you want a smaller 
> matrix from a DV image you should capture at DV resolution and use 
> your own sampling algo code.  You might want to just use a few 
> pix_info objects ins series to sample various intervals of pixel 
> values.  I also seem to recall writing some sort of pixel averaging 
> object for testing purposes - perhaps this might be useful for 
> analysis like you want to do?

yes, I thought of this averaging solution too ... I think I will do that.

> Another thing to remember is that nearly every video input/capture 
> device natively uses YUV and _NOT_ RGB color-space.  The only version 
> of GEM that doesn't do slow, painful, frame-rate killing conversion 
> is the one for OSX.

... PC-based, sorry :-)

It is worth trying though


THanks for these informations