This thesis describes and compares several methods for producing bilevel patterns to simulate grey level values for use in polygon regions as generated for computer graphics. Random distribution, ordered dither, and error diffusion methods are shown to be visually inferior for many grey levels to the proposed maxmin algorithm for producing patterns for polygon area filling procedures. Through even spatial arrangement of the pixels and taking into consideration the edges of the pattern, the number of artifacts is decreased and the accuracy in small subregions of the pattern is improved, especially at low grey levels where most pattern generators degrade. At these lower levels, the maxmin algorithm can produce pleasing patterns if given sufficient flexibility through enlarged grid sizes. At higher grey levels, the proximity of pixels does not leave sufficient room to eliminate all artifacts, but by varying the criteria of the algorithm, the patterns still appear more pleasing than other methods. / Science, Faculty of / Computer Science, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/27974 |
| Date | January 1988 |
| Creators | Kreykenbohm, Michael Walter |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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