cp950 differences between various resolutions

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Note really specific to the cp950 (but that is what i have AND LOVE) anyhow it has 3 resolution modes 1600x1200 1024x768 640x480

what i want to know is what exactly is going on when i switch between the resolutions. in reduced resolution, is it ?:

a) sampling a subset of the 2.1 million pixels (ignoring the unsampled pixels?)

b) averaging on the fly ALL 2.1 million pixels to get to the target resolution is this "averaging" (or whatever kind of math) ? -digital (ie calculated by the processor)

-physical (ie analog combination of the charges in each the silicon wells for each "pixel" in the CDD think of it as enlarging the area of each pixel, while reducing the number of pixels in the CDD array)

c) something else

I believe i understand about jpg compress and all of that jazz (i assume that it is totally a processor function). What i am trying to figure out is what does the jpeg algorithm start with.

if i could get at the .TIF for reduced resolution modes (or had a lossless jpeg) then i guess i could figure it out, but i cant

-- richard rader (richard.rader@vlsi.com), October 05, 1999


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