Input image e.g. palm imprint image, density converting method for e.g. image processing improving system, involves converting minimum local and maximum local values into minimum and maximum common values, and reconstructing input image

摘要

The method involves extracting maximum and minimum density values from pixels, where the values are common to a pixel zone`s pixels. The values are stored in pixel planes to generate maximum and minimum density planes. A set of maximum and minimum density values is sequentially extracted in another pixel zone. The highest minimum density and lowest maximum density values are adjusted as minimum local and maximum local values respectively. The local values are converted into minimum and maximum common values. An input image e.g. palm imprint, is reconstructed based on the converted values. An independent claim is also included for a device for conversion of image densities.