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Set Multiple RGB Values as Background Value for Raster

January 07 2010 | 0 comments
Categories: Map Data

I have a series of orthophotos (100+) that I would like to overlay with other layers in ArcMap. I need to remove the background value from the images, but the values are not all pure white or black (due to compression).

The Display Background Value option in Symbology tab only allows a single RGB value but not a range of values. (attached image shows background value set to 255,255,255).

Is it possible to set multiple RGB values as background or mask those background area? I would like to remove the background values without reprocessing the orthophotos and retain the overlays underneath.

Mapping Center Answer:

You will have to use image processing software to do this unless you have a mask of the areas that you want to clip out. For image display, you can set the background to one color or no color -- but for this to work, all the background cells have to have the same value, which your data do not. So your options are the pre-process the image to make all the background values the same color or clip the area of interest out of the original image, which will also result in all background values being the same.

You cannot set the background to be multiple colors.

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