Granted Patent B2

US 7,050,651 · App. 11/037,556 · Granted May 23, 2006

Abstract

Claims (49)

1. A computer program product storing computer-executable instructions defining a computer process that reduces image defects in a digital image, the computer process comprising:

providing a digital image data set in the form of a matrix of pixels;

selecting a sub-matrix comprising at least a 5×5 matrix of pixels;

identifying a pixel within the sub-matrix to be treated as a central pixel;

determining a value for at least one optical property in the central pixel;

selecting at least four pixels around the central pixel as averaging pixels, at least two of the averaging pixels being in a position in the sub-matrix that is not adjacent the position in the matrix of the central pixel;

determining a value for the at least one optical property for the at least four averaging pixels;

averaging the values for the at least one optical property for more than one of the at least four averaging pixels to provide an average treatment value for the central pixel;

assigning the average treatment value for the central pixel to the central pixel; and

storing the average treatment value assigned to the central pixel.

2. A method of filtering a digital image to produce a modified digital image, the method comprising:

specifying a filter window that includes a matrix of elements containing a reference element and a plurality of other elements, the plurality of other elements including a set of non-contiguous sampling elements;

superposing the filter window over a region of the digital image so that each element corresponds to one or more pixels in the digital image;

determining a pixel property value for each of more than one of the pixels corresponding with the non-contiguous sampling elements; and

modifying the pixel property values of the pixels corresponding with the reference element based on the pixel property values of the pixels corresponding with the non-contiguous sampling elements to produce the modified digital image averaging the pixel property values corresponding with the non-contiguous sampling elements to determine an average treatment value; and assigning the average treatment value to the pixel property values of the pixels corresponding with the reference element to produce the modified digital image.

3. The method of claim 2 wherein the plurality of other elements further includes a set of non-sampling elements, one or more of the non-sampling elements being positioned between individual non-contiguous sampling elements.

4. The method of claim 2 wherein the averaging operation comprises a weighted averaging operation.

5. The method of claim 2 wherein modifying operation comprises:

selecting one or more of the non-contiguous sampling elements; and

modifying the pixel property values of the pixels corresponding with the reference element based on the pixel property values of the pixels corresponding with the selected non-contiguous sampling elements to produce the modified digital image.

6. The method of claim 5 wherein the selecting operation comprises selecting the non-continuous sampling elements having pixel property values within a predefined range of pixel property values.

7. The method of claim 5 wherein selecting operation comprises:

ranking the non-contiguous sampling elements based on the pixel property values of each element to produce a rank order of the non-contiguous sampling elements; and

selecting non-contiguous sampling elements according to the rank order.

8. The method of claim 5 wherein selecting operation comprises:

ranking the non-contiguous sampling elements according to similarity between the pixel property values of the pixels corresponding to each non-contiguous sampling element to the pixel property values of pixels corresponding to the reference element; and

selecting non-contiguous sampling elements according to the rank order.

9. The method of claim 5 wherein selecting operation comprises:

selecting the non-continuous sampling elements having pixel property values within a predefined distance from a median of the pixel property values of the pixels corresponding to the non-continuous sampling elements.

10. A computer program product storing computer-executable instructions defining a computer process that filters a digital image to produce a modified digital image, the computer process comprising:

specifying a filter window that includes a matrix of elements containing a reference element and a plurality of other elements, the plurality of other elements including a set of non-contiguous sampling elements;

superposing the filter window over a region of the digital image so that each element corresponds to one or more pixels in the digital image;

determining a pixel property value for each of more than one of the pixels corresponding with the non-contiguous sampling elements; and

modifying the pixel property values of the pixels corresponding with the reference element based on the pixel property values of the pixels corresponding with the non-contiguous sampling elements to produce the modified digital image averaging the pixel property values corresponding with the non-contiguous sampling elements to determine an average treatment value; and assigning the average treatment value to the pixel property values of the pixels corresponding with the reference element to produce the modified digital image.

11. The computer program product of claim 10 wherein the plurality of other elements further includes a set of non-sampling elements, one or more of the non-sampling elements being positioned between individual non-contiguous sampling elements.

12. The computer program product of claim 10 wherein the averaging operation comprises a weighted averaging operation.

13. The computer program product of claim 10 wherein modifying operation comprises:

selecting one or more of the non-contiguous sampling elements; and

modifying the pixel property values of the pixels corresponding with the reference element based on the pixel property values of the pixels corresponding with the selected non-contiguous sampling elements to produce the modified digital image.

14. The computer program product of claim 13 wherein the selecting operation comprises selecting the non-continuous sampling elements having pixel property values within a predefined range of pixel property values.

15. The computer program product of claim 13 wherein selecting operation comprises:

ranking the non-contiguous sampling elements based on the pixel property values of each element to produce a rank order of the non-contiguous sampling elements; and

selecting non-contiguous sampling elements according to the rank order.

16. The computer program product of claim 13 wherein selecting operation comprises:

ranking the non-contiguous sampling elements according to similarity between the pixel property values of the pixels corresponding to each non-contiguous sampling element to the pixel property values of pixels corresponding to the reference element; and

selecting non-contiguous sampling elements according to the rank order.

17. The computer program product of claim 13 wherein selecting operation comprises:

selecting the non-continuous sampling elements having pixel property values within a predefined distance from a median of the pixel property values of the pixels corresponding to the non-continuous sampling elements.

18. The computer program product of claim 13 wherein the reference element is the center element in the filter window.

Assignments (17)