Adaptive windowing in motion detector for deinterlacer

1. A method of determining a motion value for a missing pixel in an interlaced video field using an adaptive window, the method comprising:

computing a first mean absolute difference (MAD) value for the pixel based on a 1×5 window;

computing a second MAD value for the pixel using a 3×5 window; and

selectively blending the first and second MAD values to form a resultant motion value.

2. The method of claim 1 , wherein computing the first MAD value based on the 1×5 window includes:

selecting a first 1×5 window of pixels in a first field;

selecting a corresponding second 1×5 window of pixels in a second field, the second field having a same parity as the first field;

computing absolute values of differences between values of corresponding pixels in the first 1×5 window of pixels and the second 1×5 window of pixels; and

averaging the absolute values of differences computed based on the first and second 1×5 windows.

3. The method of claim 2 , wherein computing the second MAD value further includes:

selecting a first 3×5 window of pixels in the first field;

selecting a corresponding second 3×5 window of pixels in the second field;

computing absolute values of differences between values of corresponding pixels in the first 3×5 window of pixels and the second 3×5 window of pixels; and

averaging the absolute values of differences computed based on the first and second 3×5 windows.

4. The method of claim 3 , wherein the first field is next in time relative to the field of the missing pixel, and the second field is previous in time relative to the field of the missing pixel.

5. The method of claim 3 , wherein the first field is the interlaced video field of the missing pixel.

6. The method of claim 1 , further comprising:

quantizing each of the first MAD value and the second MAD value.

7. The method of claim 1 , wherein selectively blending the first and second MAD values includes:

computing a blending factor based on values of pixels in the interlaced video; and

forming the resultant motion value using the blending factor.

8. The method of claim 7 , wherein forming the resultant motion value includes: computing a weighted average of the first and second MAD values by using the blending factor.

9. The method of claim 7 , wherein computing the blending factor includes: determining whether the pixel is at a horizontal edge of an object.

10. The method of claim 9 , wherein the resultant motion value is the first MAD value when the pixel is at a horizontal edge of an object.

11. The method of claim 1 , further comprising:

generating a value of the pixel based on the resultant motion value.

12. A method of determining a motion value for a missing pixel in an interlaced video, the method comprising:

selecting a plurality of windows, each window of the plurality of windows having dimensions distinct from dimensions of each other window of the plurality of windows;

computing a plurality of motion values for the missing pixel, each motion value being based on a respective window of the plurality of windows; and

selectively blending the plurality of motion values to form a resultant motion value.

13. The method of claim 12 , further comprising:

selecting, for each respective window of the plurality of windows, a first set of pixels from a first field, and a second set of corresponding pixels from a second field, the first field having a same parity as the second field, each of the first and second sets of pixels being a block of pixels within the respective window and having dimensions of the respective window;

wherein computing the plurality of motion values includes computing a motion value based on the respective window using values of pixels in the first set of pixels and the second set of pixels selected for the respective window.

14. The method of claim 12 , wherein selectively blending the plurality of motion values includes:

computing a blending factor based on values of pixels in the interlaced video; and

forming the resultant motion value using the blending factor.

15. The method of claim 12 , wherein selecting the plurality of windows includes selecting a first plurality of windows and a second plurality of windows, each of the first plurality of windows and the second plurality of windows being associated with pixels selected from a respective pair of fields having a same parity;

wherein computing the plurality of motion values includes computing a first plurality of motion values and a second plurality of motion values, each of the first plurality of motion values being based on a respective one of the first plurality of windows, and each of the second plurality of motion values being based on a respective one of the second plurality of windows;

wherein selectively blending the plurality of motion values includes forming a first resultant motion value by selectively blending the first plurality of motion values and forming a second resultant motion value by selectively blending the second plurality of motion values, each of the first resultant motion value and the second resultant motion value corresponding to a respective pair of fields having the same parity; and

wherein the method further comprises generating a frame motion value based on the first resultant motion value and the second resultant motion value.

16. An apparatus for detecting motion in an interlaced video signal comprising:

a frame motion detector having a first input, a second input, and an output, the first input being configured to receive a first field of the interlaced video signal and the second input being configured to receive a second field of the interlaced video signal, the second field having a same parity as the first field, and the output being configured to produce a resultant frame motion value corresponding to a missing pixel of a current field;

wherein the frame motion detector is configured to:

determine a first motion value based on the first field and the second field by using a first window having a first size,

determine a second motion value based on the first field and the second field by using a second window having a second size, and

selectively blend the first motion value and the second motion value to generate the resultant frame motion value.

17. The apparatus of claim 16 , wherein the frame motion detector is a first frame motion detector and the resultant frame motion value is a first resultant frame motion value, the apparatus further comprising:

a second frame motion detector having a first input, a second input, and an output, the first input and the second input of the second frame motion detector being configured to receive respective fields having a same parity, and the output of the second frame motion detector being configured to produce a second resultant frame motion value;

wherein the apparatus is configured to determine a frame motion value based on the first resultant frame motion value and the second resultant frame motion value.