LibGrid

## Channel Combination

The most common use case for processing imagery is to combine the red, green and blue channels of satellite imagery to yield an rgb image.

Landsat 7 example:

Red 0.63–0.69$\mu m$ 30m

Green 0.525–0.605$\mu m$ 30m

Blue 0.450–0.515$\mu m$ 30m

RGB combined, 30m

Problem: The spectral bands of the Landsat satellite do not match the natural spectrum exactly. For example, the red channel from 0.63–0.69$\mu m$ does not equal the natural red spectrum from 0.65â€“0.75$\mu m$.

As a result, the combined rgb images exhibit an unnatural pinkish tint.
To produce more natural looking images we need to apply advanced techniques.