BandMath

BandMath compares the bands at each pixel of a multiband image. The “output” can be a single band or a multiband image.

Single-band output

This is suited to multispectral images, with tens of bands. Choose the “operation”:

Operation	Output at each pixel
min	the smallest band value
max	the largest band value
mod	the modulation, (max − min) ÷ (max + min)
median	the median of the band values

The output is the same type as the input.

This is designed for hyperspectral or XRF images, with thousands of bands. Choose how to “merge” the bands over a “width”, a number of bands:

reduce averages each group of “width” bands into one band, so the output has (input bands ÷ width) bands.
blend keeps the same number of bands, but each output band is the average of the “width” neighboring bands around it.

The width must be positive, and no larger than the number of bands. The output is floating point.