Digital image filter processing

An image processing apparatus for performing filter processing on an image, in which a filter kernel having multiple coefficients corresponding to positions of pixels is applied at a target pixel position and to sample pixels positioned in the neighborhood of the target pixel position, comprising:

• a computer-readable memory constructed to store computer-executable process steps;
• and
• a processor constructed to execute the computer-executable process steps stored in the memory;
• wherein the process steps stored in the memory cause the processor to:
• assign a bin to each unique coefficient of the filter kernel;
• create a mask having respective positions corresponding to the positions of the filter kernel, wherein each respective position of the mask indexes to the bin for the coefficient corresponding to that position;
• position the mask at the target pixel position;
• accumulate the respective pixel value of each sample pixel in the indexed bin corresponding to the position of the sample pixel in the mask;
• multiply the accumulated pixel values in each respective bin by the coefficient corresponding to the bin to produce a set of resultant products;
• and
• sum the resultant products to determine a filtered pixel value at the target pixel position.

An image processing module for performing filter processing on an image, in which a filter kernel having multiple coefficients corresponding to positions of pixels is applied at a target pixel position and to sample pixels positioned in the neighborhood of the target pixel position, comprising:

• a bin assignment module assigning a bin to each unique coefficient of the filter kernel;
• a mask creation module for creating a mask having respective positions corresponding to the positions of the filter kernel, wherein each respective position of the mask indexes to the bin for the coefficient corresponding to that position;
• a positioning module for positioning the mask at the target pixel position;
• an accumulation module for accumulating the respective pixel value of each sample pixel in the indexed bin corresponding to the position of the sample pixel in the mask;
• a multiplication module for multiplying the accumulated pixel values in each respective bin by the coefficient corresponding to the bin to produce a set of resultant products;
• and
• a summation module for summing the resultant products to determine a filtered pixel value at the target pixel position.

A computer-readable storage medium storing computer-executable process steps for causing a computer to perform a method for performing filter processing on an image, in which a filter kernel having multiple coefficients corresponding to positions of pixels is applied at a target pixel position and to sample pixels positioned in the neighborhood of the target pixel position, the method comprising:

• assigning a bin to each unique coefficient of the filter kernel;
• creating a mask having respective positions corresponding to the positions of the filter kernel, wherein each respective position of the mask indexes to the bin for the coefficient corresponding to that position;
• positioning the mask at the target pixel position;
• accumulating the respective pixel value of each sample pixel in the indexed bin corresponding to the position of the sample pixel in the mask;
• multiplying the accumulated pixel values in each respective bin by the coefficient corresponding to the bin to produce a set of resultant products;
• and
• summing the resultant products to determine a filtered pixel value at the target pixel position.