Merging filters for a graphic processing unit

1. A computer-implemented method comprising:

receiving, using one or more computing devices, an input to apply a plurality of filters to a source image;

identifying, using the one or more computing devices, a first type of filter from the input;

identifying, using the one or more computing devices, a second type of filter from the input;

identifying, using the one or more computing devices, a supplemental transformation filter from the input, the supplemental transformation filter using a function to determine a color value in the source image;

merging, using the one or more computing devices, the first type of filter, the supplemental transformation filter, and the second type of filter to generate a merged filter, wherein the merged filter executes on the source image a reverse of the first type of filter to generate a first value, the supplemental transformation filter to process the first value using the function to generate a second value, and the second type of filter to process the first value and the second value to generate a third value for the destination image; and

applying, using the one or more computing devices, the merged filter on the source image to generate the destination image.

2. The computer-implemented method of claim 1 , wherein the second type of filter is a color transformation filter that maps a first color of a first pixel from the source image to a second color in the destination image.

3. The computer-implemented method of claim 1 , wherein the first type of filter is a coordinate transformation filter that maps at least one pixel location in the destination image to one or more different pixel locations in the source image.

4. The computer-implemented method of claim 1 further comprising:

determining, using the one or more computing devices, that the supplemental transformation filter is not identified in the received input;

inserting, using the one or more computing devices, a substitute supplemental transformation filter into the received input; and

merging, using the one or more computing devices, the first type of filter, the substitute supplemental transformation filter, and the second type of filter to generate the merged filter.

5. The computer-implemented method of claim 1 , wherein the second type of filter is applied on the source image in forward order of application in the merged filter.

6. The computer-implemented method of claim 1 , wherein the first type of filter is applied on the source image in reverse order of application in the merged filter.

7. The computer-implemented method of claim 1 , wherein the supplemental transformation filter is based on a fragment shader and runs in a single pass.

8. A computer program product comprising a non-transitory computer readable medium storing a computer readable program, wherein the computer readable program when executed on a computer causes the computer to perform operations comprising:

receiving an input to apply a plurality of filters to a source image;

identifying a first type of filter from the input;

identifying a second type of filter from the input;

identifying a supplemental transformation filter from the input, the supplemental transformation filter using a function to determine a color value in the source image;

merging the first type of filter, the supplemental transformation filter, and the second type of filter to generate a merged filter, wherein the merged filter executes on the source image a reverse of the first type of filter to generate a first value, the supplemental transformation filter to process the first value using the function to generate a second value, and the second type of filter to process the first value and the second value to generate a third value for the destination image; and

applying the merged filter on the source image to generate the destination image.

9. The computer program product of claim 8 , wherein the second type of filter is a color transformation filter that maps a first color of a first pixel from the source image to a second color in the destination image.

10. The computer program product of claim 8 , wherein the first type of filter is a coordinate transformation filter that maps at least one pixel location in a destination image to one or more different pixel locations in the source image.

11. The computer program product of claim 8 , wherein the operations further comprise:

determining that the supplemental transformation filter is not identified in the received input;

inserting a substitute supplemental transformation filter into the received input; and

merging the first type of filter, the substitute supplemental transformation filter, and the second type of filter to generate the merged filter.

12. The computer program product of claim 8 , wherein the first type of filter is applied on the source image in forward order of application in the merged filter.

13. The computer program product of claim 8 , wherein the second type of filter is applied on the source image in reverse order of application in the merged filter.

14. The computer program product of claim 8 , wherein the supplemental transformation filter is based on a fragment shader and runs in a single pass.

15. A system comprising:

one or more processors;

a user interface module stored on a memory and executable by the one or more processors, the user interface module configured to receive an input to apply a plurality of filters to a source image; and

a filtering engine stored on the memory and executable by the one or more processors, the filtering engine configured to:

identify a first type of filter from the input;

identify a second type of filter from the input;

identify a supplemental transformation filter from the input, the supplemental transformation filter using a function to determine a color value in the source image;

merge the first type of filter, the supplemental transformation filter, and the second type of filter to generate a merged filter, wherein the merged filter executes on the source image a reverse of the first type of filter to generate a first value, the supplemental transformation filter to process the first value using the function to generate a second value, and the second type of filter to process the first value and the second value to generate a third value for the destination image; and

apply the merged filter on the source image to generate the destination image.

16. The system of claim 15 , wherein the filtering engine comprises a color transformation module as the second type of filter for mapping a first color from the source image to a second color in the destination image.

17. The system of claim 15 , wherein the filtering engine comprises a coordinate transformation module as the first type of filter for mapping a first pixel location from the source image to a second pixel location in the destination image.

18. The system of claim 15 , wherein the filtering engine comprises a supplemental transformation module for determining whether the supplemental transformation filter is identified in the received input, responsive to determining that the supplemental transformation filter is not identified in the received input, inserting a substitute supplemental transformation filter into the received input, and merging the first type of filter, the substitute supplemental transformation filter, and the second type of filter to generate the merged filter.

19. The system of claim 15 , wherein the second type of filter is applied on the source image in forward order of application in the merged filter.

20. The system of claim 15 , wherein the first type of filter is applied on the source image in reverse order of application in the merged filter.

21. The system of claim 15 , wherein the supplemental transformation filter is based on a fragment shader and runs in a single pass.