Structure-sensitive adaptive contrast enhancement methods and their evaluation

摘要

Contrast enhancement is a fundamental step in the display of digital images whose goal is to improve human performance of visual tasks. The end result of display is the perceived brightness occurring in the human observer. Methods which incorporate local image structure in a way similar to human vision would therefore seem to have an advantage. A range of locally adaptive contrast enhancement methods are described, including a number of recently developed structure-sensitie techniques. Countering the difficulty that such methods are typically evaluated only subjectively, objective approaches for comparing the effectiveness of contrast enhancement methods are discussed.