optimal image transform

An optimal image transform for threshold-based cloud detection using heteroscedastic discriminant analysis
IVZ Marais, JA Du Preez… – International Journal of …, 2011 – Taylor
We present a simple image transform that optimally combines four image channels into a
greyscale image for threshold-based cloud detection. These image channels, namely blue,
green, red and near infrared, are present on many low Earth-orbit resource satellites.