Method and apparatus identifying halftone regions within a digital image
AssigneeAdobe Systems Incorporated
InventorRam Agrawal
Life of this patent
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Abstract
One embodiment of the present invention provides a system that identifies halftone regions within a digital image. During operation, the system receives a region from the digital image, wherein the digital image is a bi-level image, wherein each pixel has two possible color values. Next, the system computes a variation index for a region of the digital image, wherein the variation index indicates how frequently adjacent pixel values in the region differ. If the variation index for the region is greater than an upper threshold, the system determines that the region is a halftone region.
Claims20
A method for identifying halftone regions within a digital image, comprising:
- receiving a region from the digital image, wherein the digital image is a bi-level image, wherein each pixel has two possible color values;
- computing a variation index for a region of the digital image, wherein the variation index indicates how frequently adjacent pixel values in the region differ;
- and
- if the variation index for the region is greater than an upper threshold, determining that the region is a halftone region.
A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for identifying halftone regions within a digital image, the method comprising:
- receiving a region from the digital image, wherein the digital image is a bi-level image, wherein each pixel has two possible color values;
- computing a variation index for a region of the digital image, wherein the variation index indicates how frequently adjacent pixel values in the region differ;
- and
- if the variation index for the region is greater than an upper threshold, determining that the region is a halftone region.
An apparatus that identifies halftone regions within a digital image, comprising:
- a receiving mechanism configured to receive a region from the digital image, wherein the digital image is a bi-level image, wherein each pixel has two possible color values;
- an index-computing mechanism configured to compute a variation index for a region of the digital image, wherein the variation index indicates how frequently adjacent pixel values in the region differ;
- and
- an identification mechanism, wherein if the variation index for the region is greater than an upper threshold, the identification mechanism is configured to determining that the region is a halftone region
Dependencies are inferred from the claim text.