Colour texture analysis using colour histogram

The authors describe a new and systematic way of analysing colour texture. They propose to extract both spatial (i.e. texture) and spectral (i.e. colour) attributes separately from a colour image. This involves a parallel system of representation comprising two channels, one for texture representation and the other for colour description. The spatial attributes are gathered by the `local linear transform´ for texture representation as it is very suitable for statistical texture representation. The use of the three-dimensional colour histogram as the model for colour representation is proposed. As the storage and feature computation from the colour histogram are both very intensive, the authors advocate and justify the approximation of this histogram by the product of the three first-order histograms computed for the principal axis components of the colour image pixel data. Illumination invariant colour features are then defined as statistical descriptors of these lower dimensional histograms