Using the Colormap process

Legacy:

ArcGIS 10 is the last release of the stand-alone ArcGIS Image Server product. The image service definition (.ISDef) has been replaced by an improved geodatabase data model—the mosaic dataset—which can be published as an image service using the ArcGIS Server Image extension.

The Colormap process is a type of raster data renderer. It transforms the pixel values to display the raster data as either a grayscale or a red, green, blue (RGB) image, based on a color map. You can use a color map to represent analyzed data, such as a classified image, or when displaying a topographic map (or index color scanned image).

Classified image

Topographic map

The input raster dataset for the Colormap process is a one-band, unsigned 8-bit dataset, with a grayscale color space. The output is a three-band, unsigned 8-bit dataset, with an RGB color space.

Color maps contain a set of values that are associated with colors and are used to display a single-band raster consistently with the same colors. Each pixel value is associated with a color, defined as a set of RGB values.

The color map source can be an *.act file from Adobe Photoshop or a .clr file. The .clr format is an ASCII file containing information for 256 RGB colors. The entries in the ASCII color map file are listed as "pixel_value red green blue". Below is an example of the contents of a .clr file:

1 255 0 0

2 100 0 100

3 50 200 10

4 45 60 100

The .act format from Adobe Photoshop is a non-ASCII file containing information for 256 RGB colors. The first color in the table has a zero index, and the color is ordered as red, green, and blue. Each color is represented by three bytes.