Non-linear quantization and similarity matching methods for retrieving image data

摘要

A method for constructing a database having image information representing a plurality of images including the steps of: a) calculating Lx5 number of normalized edge histogram bins to generate L number of edge histograms of a target image, wherein each edge histogram has five normalized edge histogram bins and represents a spatial distribution of five reference edges in a sub-image and L is a positive integer, wherein the reference edges include four directional edges and a non-directional edge; b) non-linearly quantizing the Lx5 number of normalized edge histogram bins to generate Lx5 number of quantization index values for the target image; c) storing the Lx5 number of quantization index values to the database; and d) repeating the steps a) to c) until all of the stored images are processed to thereby construct the database having the image information.