A no-reference image enhancement quality metric and fusion technique

A no-reference image enhancement quality metric is proposed in this paper that uses three factors to score images: lightness, contrast, and noise. It has been shown in literature that certain ideal ranges for lightness and contrast exist, and image enhancement techniques tend to push an image towards these. The proposed metric gives each pixel in an image a score based on its neighborhood statistics, and these pixel scores are averaged to get an overall image quality score. An image fusion technique is also proposed that fuses multiple enhanced images into one based on the local scores obtained from the no-reference metric. It is shown that fused images score higher using the no-reference metric and also have superior visual quality.