Adaptive filtering method and apparatus for descreening...

Details Adaptive filtering method and apparatus for descreening... Adaptive filtering method and apparatus for descreening...

2005-01-04

2005-01-04

Grant, II, Jerome (Department: 2626)

Facsimile and static presentation processing

Static presentation processing

Attribute control

C382S260000, C382S264000, C382S274000

Reexamination Certificate

active

06839152

ABSTRACT:
An adaptive filtering method and apparatus for descreening a scanned halftoned image representation is disclosed. The apparatus includes an image input subsystem; a processing subsystem for processing halftoned image data provided by the image input subsystem; and software/firmware means operative on the processing subsystem for a) low-pass filtering a halftoned input pixel value provided by the image input subsystem to produce a low-pass filtered pixel value; b) notch-filtering the halftoned input pixel value to produce a notch-filtered pixel value; c) determining a local contrast value for the halftoned input pixel value; and d) producing a descreened output pixel value based on the low-pass filtered pixel value, the notch-filtered pixel value, or a combination of the low-pass filtered pixel value and the notch-filtered pixel value depending on the local contrast value.

REFERENCES:
patent: 4877310 (1989-10-01), Seachman et al.
patent: 5027078 (1991-06-01), Fan
patent: 5166810 (1992-11-01), Sorimachi et al.
patent: 5239390 (1993-08-01), Tai
patent: 5243444 (1993-09-01), Fan
patent: 5339170 (1994-08-01), Fan
patent: 5457754 (1995-10-01), Han et al.
patent: 5799112 (1998-08-01), de Queiroz et al.
patent: 6101285 (2000-08-01), Fan
patent: 6233060 (2001-05-01), Shu et al.
patent: 6603877 (2003-08-01), Bishop
patent: 0 622 949 (1994-11-01), None
patent: 0 827 333 (1998-03-01), None
patent: 2000-101845 (2000-04-01), None
M. Analoui et al.,New Results on Reconstruction of Continuous-Tone from Halftone,1992 IEEE, pp. III-313 through III-316.
Z. Fan,Retrieval of Gray Images from Digital Halftones,1992 IEEE, pp. 2477 through 2480.
R. Stevenson,Inverse Halftoning via MAP Estimation,IEEE Transactions on Image Processing, vol. 6, No. 4, Apr., 1997, pp. 574 through 583.
Y. Kim et al.,Inverse Halftoning Using Binary Permutation Filters,IEEE Transactions on Image Processing, vol. 4, No. 9, Sep., 1995, pp. 1296 through 1311.
J. Lai et al.,Inverse Error-Diffusion Using Classified Vector Quantization,IEEE Transactions on Image Processing, vol. 7, No. 12, Dec., 1998, pp. 1753 through 1758.
P. Wong,Inverse Halftoning and Kernel Estimation for Error Diffusion,IEEE Transaction on Image Processing, vol. 4, No. 4, Apr., 1995, pp. 486 through 498.
S. Hein et al.,Halftone to Continuous-Tone Conversion of Error-Diffusion Coded Images,IEEE Transactions on Image Processing, vol. 4, No. 2, Feb., 1995, pp. 208 through 216.
Reinhard Klette and Piero Zamperoni, “handbook of image processing operators” 1996, John Wiley & Sons, Chichester, England XP002253053, pp. 208-210.

Affiliated with

Also associated with

Rating

Adaptive filtering method and apparatus for descreening... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Adaptive filtering method and apparatus for descreening..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adaptive filtering method and apparatus for descreening... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3386277