Apparatus & method for descreening
AssigneeScitex Corporation Ltd.
InventorsDaniel Seidner, Dan Eylon
Life of this patent
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Abstract
Apparatus and method for descreening and for performing resolution changes on a half-tone image in order to produce a continuous tone image. The apparatus includes filter apparatus for removing screen information from the half-tone image including a plurality of different filters each providing interpolation and screen removal functions and a controller for selecting per pixel of the continuous tone image and as a function of desired resolution changes, one of the filters for operation on a neighborhood of the pixel.
Claims61
Apparatus for descreening and for performing resolution changes on a half-tone image in order to produce a continuous tone image comprising:
- filter means for removing screen information from said half-tone image comprising a plurality of different filters each providing interpolation and screen removal functions;
- and
- a controller for selecting per pixel of said continuous tone image and as a function of desired output resolution, one of said filters for operation on a neighborhood of said pixel.
Apparatus for descreening and for performing resolution changes on a half-tone image in order to produce a continuous tone image comprising:
- filter means for removing screen information from said half-tone image comprising a plurality of different filters each providing interpolation and screen removal functions;
- and
- a controller for selecting per pixel of said continuous tone image and as a function of desired resolution changes, one of said filters for operation on a neighborhood of said pixel,
- and wherein said controller comprises:
- means for calculating the location of a next pixel in said continuous tone image;
- means for choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image;
- and
- means for selecting one of said filters in accordance with said location on said predefined grid.
Apparatus for descreening and for performing resolution changes on a color printed image thereby to produce a color continuous tone image, said color printed image being separated into a plurality of input color separations and said continuous tone image being separated into output color separations, said apparatus comprising:
- filter means for removing screen information from each of said input color separations, said filter means comprising a plurality of different filters each providing interpolation and screen removal functions;
- and
- a controller for selecting, per pixel of each of said output color separations and as a function of desired output resolution, one of said filters for operation on a neighborhood of said pixel.
Apparatus for descreening and for performing resolution changes on a color printed image thereby to produce a color continuous tone image, said color printed image being separated into a plurality of input color separations and said continuous tone image being separated into output color separations, said apparatus comprising:
- filter means for removing screen information from each of said input color separations, said filter means comprising a plurality of different filters each providing interpolation and screen removal functions;
- and
- a controller for selecting, per pixel of each of said output color separations and as a function of desired resolution changes, one of said filters for operations on a neighborhood of said pixel,
- and wherein said controller comprises:
- means for calculating the location of a next pixel in said continuous tone image;
- means for choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image;
- and
- means for selecting one of said filters in accordance with said location on said predefined grid.
A method for descreening and for performing resolution changes on a half-tone image in order to produce a continuous tone image including the step of:
- removing screen information from said half-tone image via a plurality of different filters each providing interpolation and screen removal functions;
- said step of removing including the step of selecting, per pixel of said continuous tone image and as a function of desired output resolution, one of said filters for operation on a neighborhood of said pixel.
A method for descreening and for performing resolution changes on a color printed image thereby to produce a color continuous tone image, said color printed image being separated into a plurality of color separations and said continuous tone image being separated into output color separations, said method comprising the step of:
- removing screen information from each of said color separations via a plurality of different filters each providing interpolation and screen removal functions;
- said step of removing including the step of selecting, per pixel of each of said output color separations and as a function of desired output resolution, one of said filters for operation on a neighborhood of said pixel.
A method for descreening and for performing resolution changes on a half-tone image in order to produce a continuous tone image including the step of:
- removing screen information from said half-tone image via a plurality of different filters each providing interpolation and screen removal functions;
- said step of removing including the step of selecting, per pixel of said continuous tone image and as a function of desired resolution changes, one of said filters for operation on a neighborhood of said pixel,
- and wherein said step of selecting includes the steps of:
- calculating the location of a next pixel in said continuous tone image;
- choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image;
- and
- selecting one of said filters in accordance with said location on said predefined grid.
A method for descreening and for performing resolution changes on a color printed image thereby to produce a color continuous tone image, said color printed image being separated into a plurality of color separations and said continuous tone image being separated into output color separations, said method comprising the step of:
- removing screen information from each of said color separations via a plurality of different filters each providing interpolation and screen removal functions;
- said step of removing including the step of selecting, per pixel of each of said output color separations and as a function of desired resolution changes, one of said filters for operation on a neighborhood of said pixel,
- and wherein said step of selecting includes the steps of:
- calculating the location of a next pixel in said continuous tone image;
- choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image;
- and
- selecting one of said filters in accordance with said location on said predefined grid.
Apparatus for descreening comprising:
- filter means for removing screen information from an image comprising anti-aliasing filter means and screen removal filter means, wherein said anti-aliasing filter means comprises means for changing resolution of the image
- and wherein said anti-aliasing filter means comprises means for accommodating misregistration of the image.
Dependencies are inferred from the claim text.