Rotate Image through Color Wheel

MGreenb551 at aol.com MGreenb551 at aol.com
Sun Oct 19 11:13:57 EDT 2003


Sannyasin Sivakatirswami,
     I have done something like this, though not the same.   Instead of 
trying to adjust each pixel on the image, try putting an object behind the image 
and programatically change the color of the object.   By experimenting with the 
ink setting of the image, you may achieve what you are looking for much more 
easily.

          Mark Greenberg

PS   If this message comes out with HTML garbage, I will use the tedious 
method of sending in plain text next time.   AOL doesn't make plain text messaging 
easy.
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On October 5, Sannyasin Sivakatirswami wrote:

Has anyone written the code to rotate an image through the color
wheel--or a subset thereof, since 16  million is probably more than any
one would want to see, by poking the imageData of the image on some
kind of loop?

This seems doable, in theory, but then looking more closely at it,
assuming one could figure out the algorithm to do it (which I don't
have at this time), the CPU power to crunch the numbers for a real time
shift over a range of colors looks daunting and would probably run like
cold molasses...

Goal: color animate, under script control, an otherwise static color
image without having to generate an inordinately large number of frames
were one to do it as an animated GIF (where the artist makes the color
shift manually for each frame) thereby keeping the file size way down
while retaining the kids visual attention with a little on screen
action. This is for on-screen teachers' aids that want to be web
deliverable... i.e. not so giant as to required a CD to be shipped. But
a 400 x 600 pixel animated Gif with 20-30 frames starts to balloon
beyond control -- 8-10 megs for a single image in a presentation that
wants to be able to carry dozens of images... Thus the "hope" for doing
it by the numbers... to a single imported image.

Or perhaps someone knows another way to achieve the same goal?


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