Image analysis – Image enhancement or restoration – Artifact removal or suppression
Patent
1996-05-17
1998-04-07
Coles, Sr., Edward L.
Image analysis
Image enhancement or restoration
Artifact removal or suppression
382252, 358455, 358456, 358298, 358534, G06K 940
Patent
active
057374538
ABSTRACT:
An enhanced error diffusion for color and/or black-and-white halftone reproduction of gray scale, color and/or black-and-white images, features enhancements in obtaining the thresholds that are used in error diffusion halftoning as well as enhancements in how to distribute error. Thresholds according to the invention are derived by applying a standard error-diffusion technique, using a fixed threshold value of 0.5, to a constant gray level image patch which has a gray level value corresponding to an irrational number. Thresholds so-derived are well dispersed in a threshold mask and have only a limited number of threshold values; use of such thresholds in error diffusion has been found to reduce significantly the presence of structural artifacts in halftone images. As for how to distribute error, the invention provides a different error distribution matrix for each gray level value (for example, 256 different error distribution matrices) and selects one such matrix for error distribution based on the gray level value of the target pixel in the original image. Particularly in a case where the error distribution matrix is in the form: ##EQU1## for highlight/shadow regions, distributing error according to the invention has been found to reduce significantly the presence of worm-like chains in such highlight and shadow regions.
REFERENCES:
patent: 4920501 (1990-04-01), Sullivan et al.
patent: 4962542 (1990-10-01), Klees
patent: 5014333 (1991-05-01), Miller et al.
patent: 5045952 (1991-09-01), Eschbach
patent: 5050000 (1991-09-01), Ng
patent: 5060284 (1991-10-01), Klees
patent: 5107346 (1992-04-01), Bowers et al.
patent: 5111310 (1992-05-01), Parker et al.
patent: 5130823 (1992-07-01), Bowers
patent: 5150429 (1992-09-01), Miller et al.
patent: 5153925 (1992-10-01), Tanioka
patent: 5184213 (1993-02-01), Ishida
patent: 5204760 (1993-04-01), Murayama et al.
patent: 5208871 (1993-05-01), Eschbach
patent: 5226094 (1993-07-01), Eschbach
patent: 5226096 (1993-07-01), Fan
patent: 5243443 (1993-09-01), Eschbach
patent: 5245678 (1993-09-01), Eschbach et al.
patent: 5259042 (1993-11-01), Matsuki et al.
patent: 5268774 (1993-12-01), Eschbach
patent: 5276535 (1994-01-01), Levien
patent: 5278670 (1994-01-01), Eschbach
patent: 5289294 (1994-02-01), Fujisawa
patent: 5309254 (1994-05-01), Kuwabara
patent: 5313287 (1994-05-01), Barton
patent: 5317653 (1994-05-01), Eschbach et al.
patent: 5321525 (1994-06-01), Hains
patent: 5325211 (1994-06-01), Eschbach
patent: 5325448 (1994-06-01), Katayama et al.
patent: 5331429 (1994-07-01), Levien
patent: 5337160 (1994-08-01), Jones
patent: 5339171 (1994-08-01), Fujisawa et al.
patent: 5341224 (1994-08-01), Eschbach
patent: 5341228 (1994-08-01), Parker et al.
patent: 5363213 (1994-11-01), Coward et al.
patent: 5383033 (1995-01-01), Takahashi
patent: 5387987 (1995-02-01), Ino
patent: 5418626 (1995-05-01), Semasa
patent: 5422742 (1995-06-01), Ostromoukhov
patent: 5438431 (1995-08-01), Ostromoukhov
patent: 5442461 (1995-08-01), Levien
patent: 5467201 (1995-11-01), Fan
patent: 5469276 (1995-11-01), Shu
patent: 5488673 (1996-01-01), Katayama et al.
patent: 5489991 (1996-02-01), McMurray
patent: 5535019 (1996-07-01), Eschbach
patent: 5553166 (1996-09-01), Kakutani
patent: 5557709 (1996-09-01), Shu
patent: 5565994 (1996-10-01), Eschbach
patent: 5579446 (1996-11-01), Naik et al.
patent: 5621546 (1997-04-01), Klassen et al.
patent: 5625755 (1997-04-01), Shu
patent: 5648801 (1997-07-01), Beardsley et al.
B.E. Bayer, "An Optimum Method For Two-Level Rendition of Continuous-Tone Pictures", IEEE 1973 International Conference On Communications, vol. 1, Jun. 1973, pp. 26.11-26.15.
R. Eschbach, "Reduction of artifacts in error diffusion by means of input-dependent weights", Journal of Electronic Imaging, Oct. 1993, vol. 2(4), pp. 352-358.
R.W. Floyd, et al., "An Adaptive Algorithm For Spatial Grey Scale", Proc. SID, 1976, vol. 17(2), pp. 75-77.
K.T. Knox, "Edge Enhancement In Error Diffusion", SPSE's 42nd Annual Conference, May 1989, pp. 310-313.
R. Eschbach, et al., "Error-diffusion algorithm with edge enhancement", J. Opt. Soc. Am. A, vol. 8, No. 12, Dec. 1991, pp. 1844-1850.
K. Knox, et al., "Analysis of Threshold Modulation in Error Diffusion", Proc. IS&T's Eighth International Congress on Advances in Non-Impact Printing Technologies, 1992, pp. 280-282.
K.T. Knox, "Error Diffusion: A Theoretical View", SPIE 1993, vol. 1913, pp. 326-331.
C. Rosenberg, "Measurement-based evaluation of a printer dot model for halftone algorithm tone correction", Journal of Electronic Imaging, Jul. 1993, vol. 2(3), pp. 205-212.
Z. Fan, "Error diffusion with a more symmetric error distribution", SPIE vol. 2179, Mar. 1994, pp. 150-158.
P. Emmel, et al., "A Grid-Based Method For Predicting The Behaviour of Colour Printers", Proceedings of the Third IS&T/SID Color Imaging Conference 1995, pp. 71-77.
V. Ostromoukhov, et al., "Artistic Screening", Computer Graphics Proceedings, Siggraph '95, pp. 219-228.
I. Amidror, et al., "Spectral Analysis and Minimization of Moire Patterns In Color Separation", Journal of Electronic Imaging, vol. 3, No. 3, Jul. 1994, pp. 295-317.
V. Ostromoukhov, et al., "Two Approaches in Scanner-Printer Calibration: Colorimetric Space-Based Vs. `Closed-Loop`", Proceedings of the SPIE, The International Society of Optical Engineering, vol. 2170, 1994, pp. 133-142.
V. Ostromoukhov, et al., "Rotated Dispersed Dither: A New Technique for Digital Halftoning", Proceedings of the 21st International Siggraph Conference, Jul. 1994. pp. 123-130.
V. Ostromoukhov, "Hermite Approximation For Offset Curve Computation", IFIP Transactions B (Applications in Technology), vol. B-9, 1993, pp. 189-196.
V. Ostromoukhov, "Reproduction Couleur Par Trames Irregulieres Et Semi-Regulieres, 1995.
R. Ulichney, Digital Halftoning, MIT Press, 1987, Chapter 8, pp. 233-331.
P. Fink, PostScript Screening: Adobe Accurate Screens, Adobe Press 1992, Chapter 2, pp. 15-26.
Graham, Concrete Mathematics: A Foundation For Computer Science, 2nd Edition, Addison Wessley, 1994, pp. 102-105, 123-139.
Canon Information & Systems, Inc.
Coles Sr. Edward L.
Nguyen Madeleine A-V
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