An Extension of a Microcomputer Based System for Analysis of Line Drawing Quantization Schemes.

This thesis describes the extension of a microcomputer based system to analyze the performance of various grid based line drawing quantization schemes. The system is developed on a Heathkit H-89 microcomputer with a Hewlett-Packard 9874A digitizer and a Hiplot digital plotter. The capabilities of the existing system were expanded to allow real time digitizingplotting operations and to provide for encoding and analysis using variable ring quantization schemes. Comparisons of specific drawings were then made for various quantization schemes based on a distortion metric area between original and quantized image, a rate metric number of bits in the quantization, and a subjective evaluation of the smoothness of the quantized image. Results indicate that multi-ring codes usually produce less distortion in the quantized image than single ring codes require less bits for storage. Also. neither metric is a good indicator of the smoothness of the quantized image. Originator supplied keywords Line Drawing, Chain Codes, Computer Graphics.