Date of Award
Master of Science (MS)
Prof-Technical & Technology Education
The purpose of this study was to determine the validity of the energy measure developed by Geist, Reynolds, and Suggs, when used as an evaluator of digitally half-toned images. The energy measure was found to be a valid, useful tool for the evaluation of binary digital halftone quality. Data resulting from the analysis and visual comparison of fifteen different halftones supports this conclusion. Using linear regression, the coefficient of correlation between the energy measure and visual quality ratings was -0.606 using all images, and -0.936 using average results for each halftone method. These figures indicate the strong relationship between image energy and image quality. Although the energy measure was found to be accurate for different halftones of the same continuous-tone image, there is an inherent difficulty when comparing the quality of halftones of different image content. Geist, Reynold, and Suggs' algorithm does not produce values within a fixed range. A simple approximation for normalizing the energy values is proposed and used for the study, but further development is needed to obtain absolute quality rankings using this technique.
Weible, John, "Energy-Based Evaluation of Digital Halftones" (1994). Electronic Thesis Collection. Paper 39.