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Hi,
I really appreciate all the responses to my problem. I want to provide a 
bit more information in case it will save other Idrisi32 users some time. 
Many of the responses suggested I edit the composit.smp palette file to 
change the "0" color from black to white. This was my first idea, but it 
didn't solve my problem for a couple of reasons. The main one is that 
24-bit composites apparently don't use a *.smp palette file. They are a 
"true color" image. This solution might have worked with an 8-bit 
composite, but the 24-bit composites are much more appealing visually. 
Another problem with changing the palette (moot because of the first 
reason) is that my image contains some "0" values that I want to appear 
black. Other users suggested I could save time by just masking the 24-bit 
composite. Again this solution fails because of the unique nature of the 
24-bit image, which doesn't seem to be available to use as a input to other 
Idrisi32 modules. I want to thank all those who took the time to give my 
problem some thought and responded. I am including my current, rather 
cumbersome solution below. If anyone can improve on it I will update the list.

Previous posts:
Hi,
>Does anyone have a tip on how to change the black background color on 
>24-bit composites from within Idrisi32? It uses up alot of ink 
>unnecessarily. Will sum. Thanks.

Thanks to those who offered suggestions. None of them worked directly, but 
they got me to think along the right line. The specific problem was as 
follows. I have a window from a Landsat 7 scene which I have further masked 
to show only the irregularly-shaped region of interest (background = 0). 
When I create a 24-bit composite in Idrisi32 (e.g. bands 4,3,2), the 
background is given a "true color" RGB value of 0,0,0 or black. To change 
the black background to white, I started by reclassing the original boolean 
mask background value (0) to 255. I used the overlay module with each band 
to change the background value to 255. Finally, I created the composite. 
The background had an RGB value of 255,255,255 or white. This isn't the 
most efficient process, but it works.


Richard A. Rupp
Agricultural Research Technologist
Remote Sensing & GIS
Dept. of Crop & Soil Sciences
Washington State University
Pullman WA 99164-6420
Ph. 509.335.2381
FAX 509.335.8674 

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