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US 5,315,406 AGranted
Screen generation for halftone screening of images using arbitrary distribution of transformed screen coordinates
OwnerRaphael L. Levieninventor
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OwnerRaphael L. Levieninventor
Estimating the term…
A halftone screen with precisely controlled angles and rulings, including irrational screen angles and rulings, for screening photographic images is generated by representing a desired screen pattern in an irregular or non-grid like array of screen elements. In one embodiment, a random array of screen elements is used. In another embodiment, a Poisson-disk distribution of screen elements is used to improve quality. The error between an ideal screen point and an actual screen point in the transformed UV space is calculated and used as the basis for selecting an actual screen point as having the least error between the ideal and actual screen points in UV space. The number of error calculations may be reduced by storing pointers the nearest points to each screen point in transformed UV space, and by storing a plurality of successive screen values at a given angle and screen ruling corresponding to each point in the transformed UV space.
In a method for generating a halftone screened image from an original image at a desired screen angle, said method including storing a screen pattern as an array of elements representing a desired spot function, transforming a point from said original image to an ideal screen point, selecting an actual screen point in said stored screen pattern array of elements to form a generated screen pattern, and screening said original image with said generated screen pattern to form said halftone screened image, the improvement comprising:
A method for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
A method for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
In a method for generating a halftone screened image from an original image at a desired screen angle, said method including storing a screen pattern as an array of elements representing a desired spot function, transforming a point from said original image to an ideal screen point, selecting an actual screen point in said stored screen pattern array of elements to form a generated screen pattern, and screening said original image with said generated screen pattern to form said halftone screened image, the improvement comprising:
A method for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
In a method for generating a halftone screened image from an original image at a desired screen angle, said method including storing a screen pattern as an array of elements representing a desired spot function, transforming a point from said original image to an ideal screen point, selecting an actual screen point in said stored screen pattern array of elements to form a generated screen pattern, and screening said original image with said generated screen pattern to form said halftone screened image, the improvement comprising:
A method for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
In an apparatus for generating a halftone screened image from an original image at a desired screen angle, said method including storing a screen pattern as an array of elements representing a desired spot function, transform a point from said original image to an ideal screen point, selecting an actual screen point in said stored screen pattern array of elements to form a generated screen pattern, and screening said original image with said generated screen pattern to form said halftone screened means for computing an error function based on the error between said ideal screen point and actual points in said stored screen pattern array, wherein said means for computing an error function comprises means for computing an error vector between an actual screen point and said ideal screen point;
An apparatus for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
An apparatus for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
In an apparatus for generating a halftone screened image from an original image at a desired screen angle, said method including storing a screen pattern as an array of elements representing a desired spot function, transforming a point from said original image to an ideal screen point, selecting an actual screen point in said stored screen pattern array of elements to form a generated screen pattern, and screening said original image with said generated screen pattern to form said halftone screened image, the improvement comprising:
An apparatus for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
In an apparatus for generating a halftone screened image from an original image at a desired screen angle, said method including storing a screen pattern as an array of elements representing a desired spot function, transforming a point from said original image to an ideal screen point, selecting an actual screen point in said stored screen pattern array of elements to form a generated screen pattern, and screening said original image with said generated screen pattern to form said halftone screened image, the improvement comprising:
An apparatus for generating a halftone screened image from an original image at a desired screen angle, said method comprising:
Dependencies are inferred from the claim text.