The histogram is a useful graphic representation of the information content of a remotely sensed image. Histograms for each band of imagery are often displayed and analysed in many remote sensing investigations because they provide the analyst with an appreciation of the quality of the original data (e.g. whether it is low in contrast, high in contrast or multimodal in nature. [...] Tabulating the frequency of occurrence of each brightness value within the image provides statistical information that can be displayed graphically in a histogram.