The next step is to select a band combination that provides the best enhancement of features of interest in the image. This step can range from the very simple (like the three-band color combination shown here) to the very complex (a statistically derived amalgamation of several spectral bands, such as a decorrelation stretch or a Principal Components analysis).

The project’s information needs, and the potential communications use of the image products, are the primary considerations in determining the best band combination.

In this case, ETM bands 7 (reflected near-infrared energy), 4 (another near-infrared band, particularly sensitive to the presence of chlorophyll and therefore an excellent indicator of healthy vegetation), and 2 (visible green light) are displayed in red, green, and blue. This is a “false-color infrared” band composite that shows excellent differentiation of forested areas, agriculture, rock and soil types, and human infrastructure in semiarid regions. Vegetation appears in shades of green, and water is dark blue.