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Proceedings Paper

Enhancement of video imagery by modified intensity-dependent spatial summation
Author(s): Phillip G. Harnden; Franklin F. Holly; Dale R. Shires
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Paper Abstract

A contrast-enhancement algorithm has been developed that avoids the often `flat,' noisy appearance produced by techniques that rely solely on the quantization properties of the input image. The algorithm is based on the theory of intensity-dependent spatial summation (IDS) which was first reported by Cornsweet and Yellot (1985). The initial intent of their paper was to demonstrate the theory's ability to replicate certain well-known effects in human vision, such as Mach bands, Ricco's Law, and Weber's Law. The model's implementation as an image enhancement routine has predominantly emphasized its ability to enhance edges. We have modified the IDS model to produce enhancement not only at the edges but throughout the entire image profile. Enhancement is achieved by minimizing the size of the point-spread functions generated over the input. Dramatic contrast gain is realized while limiting the amount of blur introduced to the output. As a comparison to histogram equalization, which possibly collapses quantization levels while balancing their distribution, and to IDS, which resolves the quantization levels of the image towards a uniform level (except at the edges), our algorithm preserves the original brightness gradations as it expands them. Thus, the shape- from-shading cues so important to the perception of form and contour are both preserved and enhanced.

Paper Details

Date Published: 8 April 1993
PDF: 12 pages
Proc. SPIE 1903, Image and Video Processing, (8 April 1993); doi: 10.1117/12.143138
Show Author Affiliations
Phillip G. Harnden, U.S. Army Research Lab. (United States)
Franklin F. Holly, U.S. Army Research Lab. (United States)
Dale R. Shires, U.S. Army Research Lab. (United States)

Published in SPIE Proceedings Vol. 1903:
Image and Video Processing
Majid Rabbani; M. Ibrahim Sezan; A. Murat Tekalp, Editor(s)

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