308 Image Analysis and Modeling in Ophthalmology
Analyzing the texture in the Lab color space entails transforming the input image from
RGB to Lab. Next, texture features are extracted from each component separately, generat-
ing three descriptors per image that correspond to the L, a, and b components. The nal
feature vector is created by their concatenation.
16.5.3.2 RGB Color Space: Opponent Colors
The RGB color space [32] (RGB) is an additive color space dened by three chromacities:
red, blue, and green. It is one of the most commonly used color spaces for image process-
ing. However, it is not perceptually uniform and, for this reason, the opponent process
theory of human color vision, proposed by Hering [33] in the 1800s, is used in Ra ...