Title :
Digital halftoning as 2-D delta-sigma modulation
Author :
Kite, Thomas D. ; Evans, Brian L. ; Bovik, Alan C. ; Sculley, Terry L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX, USA
Abstract :
The error diffusion algorithm for digital halftoning is equivalent in form to a noise-shaping feedback coder, a class of delta-sigma modulator. The white noise assumption of the quantizer error is known to be false; in fact, the quantizer error is seen to be highly correlated with the input image. To account for this correlation, we use a gain model for the quantizer. This model accurately predicts the edge sharpening and noise shaping caused by all error diffusion schemes. It also permits an extension of error diffusion to oversampled imagery
Keywords :
correlation methods; error analysis; feedback; filtering theory; image coding; image sampling; quantisation (signal); sigma-delta modulation; white noise; 2D delta-sigma modulation; correlation; delta-sigma modulator; digital halftoning; edge sharpening; error diffusion algorithm; error filters; gain model; input image; noise shaping; noise-shaping feedback coder; oversampled imagery; quantizer error; white noise; Delta modulation; Delta-sigma modulation; Digital modulation; Equivalent circuits; Feedback; Filters; Modulation coding; Noise shaping; Predictive models; White noise;
Conference_Titel :
Image Processing, 1997. Proceedings., International Conference on
Conference_Location :
Santa Barbara, CA
Print_ISBN :
0-8186-8183-7
DOI :
10.1109/ICIP.1997.648084
