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US 2007/0182995 A1Published application
Methods and systems for descreening a digital image
AssigneeSharp Laboratories of America, Inc.
InventorJohn Dolan
Life of this patent
Estimating the term…
Abstract
Embodiments of the present invention comprise methods and systems for descreening a digital image.
Claims20
A method for modifying an image, said method comprising:
- a) determining a first image gradient magnitude of said image in a first direction;
- b) determining a second image gradient magnitude of said image in a second direction;
- c) determining a second derivative of said image in said first direction;
- d) determining a second derivative of said image in said second direction;
- e) adjusting said first image gradient magnitude by a first multiplicative scaling factor and a first additive factor to create a first adjusted gradient factor;
- f) adjusting said second image gradient magnitude by a second multiplicative scaling factor and a second additive factor to create a second adjusted gradient factor;
- g) dividing said second derivative in a first direction by said first adjusted gradient factor to create a first correction;
- h) dividing said second derivative in a second direction by said second adjusted gradient factor to create a second correction;
- and
- i) generating said modified image by modifying said image using said first correction and said second correction.
7 more elements
A method for generating a modified version of an image while preserving sharp image features, said method comprising iterations wherein each iteration comprises performing the following on a current version of an image:
- a) determining a first image gradient magnitude of said current version of said image in a first direction;
- b) determining a second image gradient magnitude of said current version of said image in a second direction;
- c) determining a second derivative of said current version of said image in said first direction;
- d) determining a second derivative of said current version of said image in said second direction;
- e) adjusting said first image gradient magnitude by a first multiplicative scaling factor and a first additive factor to create a first adjusted gradient factor;
- f) adjusting said second image gradient magnitude by a second multiplicative scaling factor and a second additive factor to create a second adjusted gradient factor;
- g) dividing said second derivative in a first direction by said first adjusted gradient factor to create a first correction;
- h) dividing said second derivative in a second direction by said second adjusted gradient factor to create a second correction;
- and
- i) generating said modified version image by modifying said current version of said image using said first correction and said second correction.
7 more elements
A system for correcting an image, said system comprising:
- a) a correction calculator producing a correction signal said correction calculator further comprising
- i) an image-gradient-magnitude calculator;
- ii) a second-derivative calculator;
- and
- iii) an image-gradient-magnitude adjustor;
- and
- b) a correction circuit further comprising a corrector for correcting said image based on said correction signal.
4 more elements
Dependencies are inferred from the claim text.