Title :
Color error diffusion with generalized optimum noise shaping
Author :
Damera-Venkata, Niranjan ; Evans, Brian L.
Author_Institution :
Halftoning & Image Process. Group, Hewlett-Packard Labs., Palo Alto, CA, USA
Abstract :
We optimize the noise shaping behavior of color error diffusion by designing an optimized error filter based on a proposed noise shaping model for color error diffusion and a generalized linear spatially-invariant model of the human visual system. Our approach allows the error filter to have matrix-valued coefficients and diffuse quantization error across channels in an opponent color representation. Thus, the noise is shaped into frequency regions of reduced human color sensitivity. To obtain the optimal filter, we derive a matrix version of the Yule-Walker equations which we solve by using a gradient descent algorithm
Keywords :
FIR filters; gradient methods; image colour analysis; image representation; matrix algebra; noise; optimisation; two-dimensional digital filters; Yule-Walker equations; color error diffusion; diffuse quantization error; frequency regions; generalized linear spatially-invariant model; generalized optimum noise shaping; gradient descent algorithm; human color sensitivity; human visual system; images; matrix version; matrix-valued coefficients; opponent color representation; optimal filter; optimized error filter; Colored noise; Design optimization; Equations; Frequency; Humans; Noise reduction; Noise shaping; Nonlinear filters; Quantization; Visual system;
Conference_Titel :
Image Processing, 2001. Proceedings. 2001 International Conference on
Conference_Location :
Thessaloniki
Print_ISBN :
0-7803-6725-1
DOI :
10.1109/ICIP.2001.958683
