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Re: color_quan - how for exactly 256 colors? [message #36798 is a reply to message #36682]

Fri, 24 October 2003 09:17

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

JD Smith writes:

> Sorry, this is a Perl comment character slipping in... too much Perl'ing
> for IDLWAVE lately (hidden IDLWAVE rumor of the week: an IDL6 version with
> full doc support should be out early next week). It should read:
>
> wh=where(h gt 0,cnt) ; Should be fewer than 256
>
> That is, you'd better have fewer than 256 colors in your rgb image if
> you'd like to create an exact indexed image from it. Also note that the
> original r,g, & b were intended to be *images*, one for each color plane
> of your 24bit image, i.e. I should have written:
>
> rgb_image=r_image+256L*(g_image+256L*b_image)
>
> Got Charm?

Oh, right. Well, yes, that does work nicely. :-)

But, of course, we still have the Color_Quan-like
color table and image. How about extra credit for getting us
back to the original color table vectors and 2D image?

What I wanted to use this for was getting a 2D image
from a pixmap. This would be *so* much more convenient
than having to draw the darn picture in the Z buffer. :-(

Cheers,

David
--
David W. Fanning, Ph.D.
Fanning Software Consulting, Inc.
Phone: 970-221-0438, E-mail: david@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155

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[Message index]

		color_quan - how for exactly 256 colors? By: justspam03 on Thu, 16 October 2003 08:39
		Re: color_quan - how for exactly 256 colors? By: justspam03 on Sun, 19 October 2003 06:29
		Re: color_quan - how for exactly 256 colors? By: JD Smith on Fri, 17 October 2003 14:35
		Re: color_quan - how for exactly 256 colors? By: David Fanning on Fri, 17 October 2003 12:57
		Re: color_quan - how for exactly 256 colors? By: JD Smith on Fri, 17 October 2003 11:57
		Re: color_quan - how for exactly 256 colors? By: David Fanning on Fri, 24 October 2003 08:34
		Re: color_quan - how for exactly 256 colors? By: David Fanning on Fri, 24 October 2003 09:17
		Re: color_quan - how for exactly 256 colors? By: JD Smith on Fri, 24 October 2003 08:55

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