Archived posting to the Leica Users Group, 2002/02/10
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Jim Brick wrote:
> You must
> have a sampling rate at least four times the data rate.
Nice explanation,
Here are some diagrams I use to explain it to myself:
Twice the data rate is good enough for black & white.
Example:
Pixels: PIXELA--space--PIXELB--space
Sample: 1 2 3 4
So if each pixel can differentiate shades of gray, resolving two bits
requires four samples (twice the number of pixels).
If it takes four pixels (instead of 1) for each color bit, then:
space PIXEL2A space space space PIXEL2B space space
Pixels: PIXEL1A space PIXEL3A space PIXEL1B space Pixel3B space
space PIXEL4A space space space PIXEL4B space space
Sample: 1 2 3 4 5 6 7 8
So for color, resolving two bits requires 8 samples (four times the number
of pixels).
Which, of course, is just what you said.
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