Method and apparatus for deinterlacing interleaved video

1. A method of de-interlacing interlaced fields of video for display on a progressive display device comprising:

(a) providing at least one candidate motion vector per scan line; and

(b) determining at least one final motion vector per scan line of interlaced video for use in de-interlacing the interlaced fields, by iteratively changing the at least one candidate motion vector per scan line based on pixel intensities from each of a plurality of same polarity fields at locations along a single dimension.

2. The method of claim 1 wherein determining, at least one final motion vector per scan line of interlaced video for use in de-interlacing the interlaced fields, includes:

(c) storing data representing a previous field and data representing a next field of the same polarity as the previous field;

(d) applying the at least one per scan line candidate motion vector to spatially corresponding pixels in one dimension in a first field, to produce motion vector compensated pixels associated with a second field and same polarity field;

(e) determining at least one per scan line value based on the comparison of the produced motion compensated pixels to pixel intensities associated with spatially corresponding pixels in the second same polarity field; and

(f) providing a new candidate motion vector in response to the at least one per scan line value.

3. The method of claim 2 including confirming that the new candidate is the final per scan line motion vector by providing another candidate motion vector and repeating steps (d)-(f) such that if the per scan line value becomes more undesirable the new candidate motion vector is selected as the at least one final per scan line motion vector.

4. The method of claim 2 including generating a motion history map on a per pixel basis and de-interlacing pixels from at least the first and second fields using the at least one final motion vector per scan line for at least a plurality of pixels determined to have motion in the scan line based on the motion history map.

5. The method of claim 2 wherein determining at least one per scan line value based on the comparison of the produced motion compensated pixels to pixel intensities associated with spatially corresponding pixels in the second same polarity field includes:

generating a first per scan line value representing a number of pairs of spatially corresponding pixels that have an unacceptable pixel intensity difference;

generating a second per scan line value representing a number of pairs of spatially corresponding pixels that have an acceptable pixel intensity similarity; and

generating a sum of absolute differences based on the first and second cumulative difference count values.

6. The method of claim 5 including storing the first and second per scan line values and the sum of absolute differences for each scan line of interest.

7. The method of claim 1 including applying the at least one final per scan line motion vector to either a next field or a new incoming field.

8. The method of claim 1 including, after the final motion vectors are selected for all scan lines, the method includes assigning a common scan line motion vector to any scan lines in the band of neighboring scan lines that have different per scan line motion vectors from the common scan line motion vector.

9. An apparatus for de-interlacing interlaced fields of video for display on a progressive display device comprising:

a frame buffer containing at least a plurality of same polarity fields;

control logic, operatively coupled to the frame buffer, and operative to provide at least one candidate motion vector per scan line, and to determine at least one final motion vector per scan line of interlaced video for use in de-interlacing the interlaced fields, by iteratively changing the at least one candidate motion vector per scan line based on pixel intensities from each of a plurality of same polarity fields at locations along a single dimension.

10. The apparatus of claim 9 wherein the plurality of same field in the frame buffer includes data representing a previous field of the same polarity and data representing a next field of the same polarity, and wherein the control logic is operative to:

(a) apply the at least one per scan line candidate motion vector to spatially corresponding pixels in one dimension in a first field, to produce motion vector compensated pixels associated with a second same polarity field;

(b) determine at least one per scan line value based on the comparison of the produced motion compensated pixels to pixel intensities associated with spatially corresponding pixels in the second same polarity field; and

(c) provide a new candidate motion vector in response to the at least one per scan line value.

11. The apparatus of claim 10 where the control logic is operative to confirm that the new candidate is the at least one final per scan line motion vector by providing another candidate motion vector and is operative to repeat operations (a)-(c) such that if the at least one per scan line value becomes more undesirable the new candidate motion vector is selected as the final per scan line motion vector.

12. The apparatus of claim 10 wherein the control logic generates a motion history map on a per pixel basis and wherein the apparatus includes a de-interlacer that de-interlaces pixels from at least the first and second fields using the at least one final motion vector per scan line for at least a plurality of pixels determined to have motion in the scan line.

13. The apparatus of claim 10 wherein the control logic is operative to:

generate a first per scan line value representing a number of pairs of spatially corresponding pixels that have an unacceptable pixel intensity difference;

generate a second per scan line value representing a number of pairs of spatially corresponding pixels that have an acceptable pixel intensity difference; and

generate a sum of absolute differences, per scan line, based on the first and second per scan line values.

14. The apparatus of claim 13 including, for each scan line:

a first counter that contains the first per scan line value;

a second counter that contains the second per scan line value; and

an accumulator that contains the sum of absolute differences based on the first and second per scan line values.

15. The apparatus of claim 10 wherein the scan line is a scan line associated with either a vertical direction or a horizontal direction.

16. The apparatus of claim 9 wherein the control logic is operative to apply the at least one final per scan line motion vector to either a next field or a new incoming field.

17. The apparatus of claim 9 wherein the control logic is operative to, after the final motion vectors are selected for all scan lines, assigning a common scan line motion vector to any scan lines in the band of neighboring scan lines that have different per scan line motion vectors from the common scan line motion vector.