Raw Mode for Color CCD
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Copyright 2004 Martin Burri
Reasoning for Color RAW mod

The transfer rate of a WebCam requires a lossy compression to achieve the specified 30fps frame rate at full resolution. These losses will degrade the image quality for astro imaging and must be minimized therefore.


Color Image compression issues (YUV format)


Color RAW mode principle

As the CCD has true 640x480 photosites but covered by a bayer filter one does disable the degrading interpolation used for color CCD chips to let pass the raw image to the computer. Taking only the Y plane (luminance channel) one has the least compression applied - rebuilding the color image on the receiving computer will usually lead to a better final image.


Color Image compression applied

Using again a clever program ;-) one can disable the cameras de-bayer algorithm and reduce the compression as best as possible the which leaves all pixels un-interpolated pass through up to the receiving end.