How to create a color composite

A color composite is created by combining three raster images (bands/maps). One map is displayed in shades of red, one in shades of green and one in shades of blue. Putting the three bands together in one color composite can give a better visual impression of the reality on the ground, than displaying one band at a time.

There are three types of color composites: natural color composites, pseudo natural color composites and false color composites. Natural color composites are made of the green, blue and red part of the spectrum. This results in an image with realistic colors. A pseudo color composite is created with other parts of the spectrum, but the result has natural looking colors. In false color composites the colors in the image are not the same as in reality: for instance, healthy vegetation is red and urban areas are blue.

In ILWIS, there are two ways in which you can display or create a color composite:

Interactive color composites:

An interactive color composite can be created when your graphics board is configured to use more than 256 colors, for instance High Color 16-bit, or True Color 24-bit (see Display Settings in Windows' Control Panel).

To obtain an interactive color composite:

When you use one of these methods, first the Show Map List as Color Composite dialog box will appear: you have to select a map list. After you selected a map list, the Display Options Map List as Color Composite dialog box will appear, see below.

To obtain an interactive color composite, you can also:

The Display Options - Map List as Color Composite dialog box will appear:

The interactive color composite will be displayed in a map window.

You can easily change intervals, select other bands, etc. by changing the display options of the map list:

To save an interactive color composite, save the contents of the map window as a map view. Open the File menu in the map window and choose the Save View command.

Permanent color composites:

The output of the Color composite operation is stored as a raster map on disk.

To create a permanent color composite:

The Color Composite dialog box appears:

See also: