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Re: Colored image [message #41060 is a reply to message #41059]

Thu, 23 September 2004 08:45

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

Julio writes:

> I'm using the following code to generate a JPEG of an image. The
> figure is generated in black and white format. Does anybody know how
> can I generate a colored image?? (e.g. using a color table).
>
> Thanks!
>
> image=[(ndvi)]
> ndvi_jpg='ndvi.jpg'
> ndvi = HIST_EQUAL(ndvi, percent=2)
> WRITE_JPEG, ndvi_jpg, ndvi, QUALITY=100, order=1

If you are talking about talking a 2D 8-bit image,
and saving it as a 24-bit color JPEG image, you might
do something like this:

Loadct, 5 ; Load a color table
TVLCT, r, g, b, /Get ; Get the color table vectors
s = Size(image2d, /Dimensions) ; Size of 2D image
image24 = BytArr(3, s[0], s[1]) ; Create 24-bit image.
image24[0,*,*] = r[image2d] ; Create color lookup planes.
image24[1,*,*] = g[image2d]
image24[2,*,*] = b[image2d]
Write_JPEG, 'myimage.jpg, image24, True=1, Quality=100

If you want the order to be reversed, I wouldn't use the ORDER
keyword, which I find completely unreliable, rather, I would
reverse the Y data:

Write_JPEG, 'myimage.jpg, Reverse(image24,3), True=1, Quality=100

Cheers,

David

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

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[Message index]

		Re: Colored image By: David Fanning on Thu, 23 September 2004 08:52
		Re: Colored image By: David Fanning on Thu, 23 September 2004 08:45
		Re: Colored image By: julio on Fri, 24 September 2004 13:19

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