Re: Color Table Animation
Re: Color Table Animation
- Subject: Re: Color Table Animation
- From: Stefan Werner <email@hidden>
- Date: Fri, 26 Jan 2007 10:21:34 +0100
On Jan 26, 2007, at 8:34 AM, Steve Sheets wrote:
Remember in the days when graphics cards had limited amount of
pixels, and the graphic bitmaps had graphic lookup tables?
For those of us who do, we also remember Color Table Animation, a
cute trick where we created animation not by modifying the bits in
the bitmap, but by modifying the content of the color lookup
table. If you rotated the values, you would create a cool Rainbow
pattern rotation.
Faint memories of Deluxe Paint on a 50Hz interlaced screen...
Has anyone create this same effect using NSImages (or possibly Core
Images)? Has anyone posted any source code examples? Most image
manipulation is with 24 bits per pixel data, where there is no
color lookup table. If anyone would have some suggestions or
examples, I would appreciate it.
I think CoreImage should allow you create lookup tables. You would
create your indexed bitmap as a grayscale image (= 256 colors in your
palette), then have another image that represents your lookup table:
256 pixels wide, <your number of frames> high. Then your CoreImage
filter takes the gray value of the pixel in the source image as x
coordinate, the current animation frame as y coordinate and the
output value would be the pixel it sees at that position in the
lookup table.
I hope this was not too confusing.
Stefan
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