A Structural Approach to Adaptive Inverse Halftoning for Document Images
This paper describes an efficient algorithm for inverse halftoning of scanned color document images to resolve problems with interference patterns such as moiré and graininess when the images are displayed or printed out. The algorithm is suitable for software implementation and useful for high quality printing or display of scanned document images delivered via networks from unknown scanners. A multi-resolution approach is used to achieve practical processing speed under software implementation. Through data-driven, adaptive, multi-scale processing, the algorithm can cope with a variety of input devices and requires no information on the halftoning method or properties (such as coefficients in dither matrices, filter coefficients of error diffusion kernels, screen angles, or dot frequencies). Effectiveness of the new algorithm is demonstrated through real examples of scanned color document images.
KeywordsOriginal Image Software Implementation Document Image Input Device Continuous Tone
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