Auto-contrast enhancement system

摘要

An auto-contrast enhancement system includes a human visual system (HVS)-based local difference (LD) histogram unit configured to build a LD histogram with respect to intensity values; a histogram classifier configured to categorize histograms of input images based on distribution properties; and a histogram equalization (HE) unit configured to process the input image according to a result of the HVS-based LD histogram unit and the enhancement level determined in the histogram classifier.

主权项

1. An auto-contrast enhancement system, comprising a processor executing the following elements:
a human visual system (HVS)-based local difference (LD) histogram unit coupled to receive an input pixel of an input image in order to build a LD histogram with respect to intensity values; a histogram classifier configured to categorize histograms of input images based on distribution properties, thereby deriving a plurality of classes; and a histogram equalization (HE) unit configured to process the input image according to a result of the HVS-based LD histogram unit and an enhancement level determined in the histogram classifier; wherein all the intensity values are segmented into a plurality of regions according to human visual sensitivity; in the HVS-based LD histogram unit, when an intensity difference between a current pixel and a preceding neighboring pixel of the input image is larger than a predetermined threshold value, the intensity value of the current pixel is accumulated into the LD histogram.