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

摘要

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 digitizing/plotting 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.