CONTRAST FOR RGB IMAGES IN A GIS APPLICATION

摘要

Disclosed herein is a method and system for performing normalization of an image using a cumulative histogram and a common color map for the R, G and B channels. On receiving an instruction from a user to normalize an image, the histogram for individual channels of the image is computed. The cumulative histogram from the histogram for individual channels is computed. The linear histogram cut off percentage is tripled. The min and max positions using the histogram stretch after the percentage cutoff is adjusted. The colormap is computed using the cumulative histogram and the linear histogram cut off percentage. The colormap is applied to the image data.

主权项

1. A method for performing normalization of an image in a Geographic Information Systems (GIS) application, the method comprising
computing a histogram for each individual channel of the image; computing a cumulative histogram from the histogram for each individual channel; tripling an intended linear histogram cut off percentage to obtain a new value of linear histogram cut off percentage; computing a colormap using the new value of the linear histogram cut off percentage and the cumulative histogram cut off percentage; and applying the colormap to the image data to obtain the normalized image.