brokev03

Build attribute table *from* colormap?

Discussion created by brokev03 on Jan 15, 2013
Hi.

I have a lot of rasters (.img) that contain colormaps.  Each raster has 70+ classes, but they are all represented as one of only 4 colors in the colormap.  I need to reclassify all areas which appear as green to 1, and all other areas to 0.  The problem is that each raster has it's own colormap, so I can't simply create one reclassification table and apply it to all rasters. None of the other attributes for the rasters have any correlation with the on-screen colormap-generated color. When I use the "identify" tool on a pixel, I can see an attribute called "color(a,r,g,b)". This attribute does not show up in the attribute table.  Is there any way I can transfer this attribute into something that could be used in a raster analysis operation? 

Thanks!

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