Image Quality Assessment for Color Halftone Images Based on Color Structural Similarity
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
Multi-Level Confined Error Diffusion Algorithm for Flat Panel Display
IEICE - Transactions on Information and Systems
Halftone visual cryptography via error diffusion
IEEE Transactions on Information Forensics and Security
IEEE Transactions on Image Processing
Green noise digital halftoning with multiscale error diffusion
IEEE Transactions on Image Processing
A gradient-based adaptive error diffusion method with edge enhancement
Expert Systems with Applications: An International Journal
Multipurpose color image watermarking algorithm based on IWT and halftoning
ACS'10 Proceedings of the 10th WSEAS international conference on Applied computer science
Journal of Visual Communication and Image Representation
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Grayscale digital image halftoning quantizes each pixel to one bit. In error diffusion halftoning, the quantization error at each pixel is filtered and fed back to the input in order to diffuse the quantization error among the neighboring grayscale pixels. Error diffusion introduces nonlinear distortion (directional artifacts), linear distortion (sharpening), and additive noise. Threshold modulation, which alters the quantizer input, has been previously used to reduce either directional artifacts or linear distortion. This paper presents an adaptive threshold modulation framework to improve halftone quality by optimizing error diffusion parameters in the least squares sense. The framework models the quantizer implicitly, so a wide variety of quantizers may be used. Based on the framework, we derive adaptive algorithms to optimize 1) edge enhancement halftoning and 2) green noise halftoning. In edge enhancement halftoning, we minimize linear distortion by controlling the sharpening control parameter. We may also break up directional artifacts by replacing the thresholding quantizer with a deterministic bit flipping (DBF) quantizer. For green noise halftoning, we optimize the hysteresis coefficients