Back to results
US 8,265,413 B2Granted
Digital image degraining filter and method
AssigneeHewlett-Packard Development Company, L.P.
InventorPeter Majewicz
Life of this patent
Estimating the term…
Abstract
A method of filtering and a degraining filter employ lowest edge activity (LEA) to assign a pixel value in a filtered image. A method of filtering includes selecting a set of pixels that includes a central pixel and pixels surrounding the central pixel from a digital image. The set has a plurality of subsets of pixels where at least one subset includes the central pixel. The method of filtering further includes assigning a value of a corresponding central pixel in a filtered image. The assigned value is a mean value of pixels in an identified subset of the plurality having the LEA. A degraining filter includes a processor, a memory and a computer program having instruction that implement selecting the set, identifying the subset with LEA and assigning the value.
Claims18
A method of filtering a digital image, the method comprising:
- selecting a set of pixels from the digital image, the set comprising a central pixel and pixels surrounding the central pixel, the set having a plurality of subsets of pixels, at least one subset including the central pixel;
- and
- assigning a value of a corresponding central pixel in a filtered image, the assigned value being a mean value of pixels in an identified subset of the plurality, the identified subset having a lowest edge activity;
- wherein the filtered image is one or more of stored in a memory, displayed to a user, passed to another image processing operation and transmitted over a communication channel, and wherein selecting a set of pixels employs a three-by-three window centered on the central pixel that has eight pixels surrounding the central pixel.
1 more element
A method of filtering a digital image, the method comprising:
- selecting a set of pixels from the digital image, the set comprising a central pixel and pixels surrounding the central pixel, the set having a plurality of subsets of pixels;
- and
- assigning a value of a corresponding central pixel in a filtered image, the assigned value being a mean value of pixels in an identified subset of the plurality, the identified subset having a lowest edge activity;
- wherein the filtered image is one or more of stored in a memory, displayed to a user, passed to another image processing operation and transmitted over a communication channel, and wherein the plurality of subsets includes four quadrant subsets, a border subset and a subset that includes all of the pixels in the selected set.
1 more element
A method of filtering a digital image, the method comprising:
- selecting a set of pixels from the digital image, the set comprising a central pixel and pixels surrounding the central pixel, the set having a plurality of subsets of pixels, at least one subset including the central pixel;
- and
- assigning a value of a corresponding central pixel in a filtered image, the assigned value being a mean value of pixels in an identified subset of the plurality, the identified subset having a lowest edge activity;
- wherein the filtered image is one or more of stored in a memory, displayed to a user, passed to another image processing operation and transmitted over a communication channel, and wherein the identified subset having the lowest edge activity is the subset of the plurality having a lowest weighted standard difference.
1 more element
A method of filtering a digital image, the method comprising:
- selecting a set of pixels from the digital image, the set comprising a three-by-three array of pixels including a central pixel, the set having a plurality of subsets of pixels, at least one subset including the central pixel;
- identifying a subset of the plurality that has a lowest edge activity;
- and
- assigning a value of a corresponding central pixel in a filtered image, the assigned value being a mean value of pixels in the identified subset,
- wherein the filtered image is one or more of stored in a memory, displayed to a user, passed to another image processing operation and transmitted over a communication channel.
2 more elements
A degraining image filter, comprising:
- a processor;
- a memory;
- and
- a computer program stored in the memory, the computer program having instructions that when executed by the processor implement:
- selecting a set of pixels from a digital image, the set comprising a central pixel and surrounding pixels contiguous with the central pixel, the set having a plurality of subsets of pixels, at least one subset including the central pixel;
- identifying a subset of the plurality that has a lowest edge activity;
- assigning a value to a central pixel in a filtered image, the assigned value being a mean value of pixels in the identified subset;
- and
- determining a weighted standard difference for each subset in the plurality of subsets, a subset having a lowest weighted standard difference being the identified subset.
6 more elements
A degraining image filter, comprising:
- a processor;
- a memory;
- and
- a computer program stored in the memory, the computer program having instructions that when executed by the processor implement:
- selecting a set of pixels from a digital image, the set comprising a central pixel and surrounding pixels contiguous with the central pixel, the set having a plurality of subsets of pixels;
- identifying a subset of the plurality that has a lowest edge activity;
- and
- assigning a value to a central pixel in a filtered image, the assigned value being a mean value of pixels in the identified subset;
- wherein the plurality of subsets comprises four quadrant subsets, a border subset, and a subset that includes all of the pixels in the set of pixels.
6 more elements
A degraining image filter, comprising:
- a processor;
- a memory;
- and
- a computer program stored in the memory, the computer program having instructions that when executed by the processor implement:
- selecting a set of pixels from a digital image, the set comprising a central pixel and surrounding pixels contiguous with the central pixel, the set having a plurality of subsets of pixels, at least one subset including the central pixel;
- identifying a subset of the plurality that has a lowest edge activity;
- and
- assigning a value to a central pixel in a filtered image, the assigned value being a mean value of pixels in the identified subset;
- wherein the selected set comprises a three-by-three array of pixels.
6 more elements
A degraining image filter, comprising:
- a processor;
- a memory;
- and
- a computer program stored in the memory, the computer program having instructions that when executed by the processor implement:
- selecting a set of pixels from a digital image, the set comprising a central pixel and surrounding pixels contiguous with the central pixel, the set having a plurality of subsets of pixels, at least one subset including the central pixel;
- identifying a subset of the plurality that has a lowest edge activity;
- and
- assigning a value to a central pixel in a filtered image, the assigned value being a mean value of pixels in the identified subset
- wherein the digital image has a plurality of channels, the filtered image having a corresponding plurality of channels, and wherein the instructions that implement selecting a set of pixels, identifying a subset and assigning a value are applied to a first channel of the plurality of channels, and wherein the computer program further comprises instructions that implement:
- selecting a similar subset of pixels from a second channel of the plurality of channels, the similar subset of the second channel corresponding to the identified subset of the first channel;
- and
- assigning a value to a central pixel in the second channel of the filtered image, the assigned value being a mean value of pixels in the selected similar subset of the second channel.
9 more elements
Dependencies are inferred from the claim text.