[Mapserver-users] tiffs and 256 colors

[Dylan Keon]

I'm trying to display a colored tiff (single DRG 1:24K quad) on top of a 
grayscale shaded relief tiff.  When using 8-bit PNG output, the DRG 
appears as grayscale if both layers are displayed at the same time.  If 
I turn off the shaded relief layer, the DRG is colored correctly.

I've reduced the color depth of the grayscale shaded relief image to 64 
colors using Imagemagick, but still have the same problem.  Shouldn't 
that make enough colors available between the shaded relief (64 colors) 
and the DRG (12 colors)?

I've experimented with both 3.6.4 and today's 3.7 CVS version.  I'm 
doing this through a PHP MapScript application, but I get the same 
result with each version's shp2img.  It does work ok if I use 24-bit 
output in 3.7, but I'd like to stick with 8-bit if I can.

Thanks for any tips.

--Dylan