Patent ID: 6421090
Filing Date: 2002-07-16
Classification: H04N

Abstract:
A method for interpolating a pixel during the deinterlacing of a video signal, the video signal including at least two fields of interlaced scan lines, each scan line including a series of pixels having respective intensity values, the method comprising:generating a motion value representative of the motion between successive frames about the pixel, wherein the motion value is generated by, for each of a plurality of pixel segments from successive frames about the pixel, calculating a plurality of differences, determining the greatest of the calculated plurality of differences, and determining the motion value from a look-up table using the greatest of the calculated plurality of differences, where the look-up table is selected from a plurality of look-up tables depending upon whether an edge exists about the pixel; detecting an edge direction about the pixel, by: forming the respective differences for a first plurality of pixel pairs, each pixel pair comprising two pixels from scan lines respectively above and below the pixel, each pixel pair for the first plurality of pixel pairs having a first common direction, calculating a first combined difference for the first plurality of pixel pairs from the respective differences for the first plurality of pixel pairs; forming the respective differences for a second plurality of pixel pairs, each pixel pair comprising two pixels from scan lines respectively above and below the pixel, each pixel pair for the second plurality of pixel pairs having a second common direction, calculating a second combined difference for the second plurality of pixel pairs from the respective differences for the second plurality of pixel pairs, comparing the difference between the second combined difference and the first combined difference with an edge threshold to determine whether an edge exists, forming the respective differences for a third plurality of pixel pairs, each pixel pair comprising two pixels from scan lines respectively above and below the pixel, each pixel pair for the third plurality of pixel pairs having a third common direction, calculating a third combined difference for the third plurality of pixel pairs from the respective differences for the third plurality of pixel pairs, and if an edge exists, comparing the third combined difference with the first and second combined differences to determine the edge direction; performing an edge adaptive interpolation at the pixel, using the detected edge direction, by: if the edge direction is substantially vertical, then forming an intermediate pixel value by averaging at least one pixel substantially directly above and at least one pixel substantially directly below the pixel, if the edge direction is approximately 45 degrees from vertical, then forming the intermediate pixel value by averaging at least one pixel above and at least one pixel below the pixel and substantially along a 45 degree axis through the pixel, and if the edge direction is approximately 135 degrees from vertical, then forming the intermediate pixel value by averaging at least one pixel above and at least one pixel below the pixel and substantially along a 135 degree axis through the pixel; and performing a motion adaptive interpolation at the pixel, using the generated motion value, by multiplying the intermediate pixel value by the motion value and adding the value of the pixel from the next field multiplied by the difference between a maximum motion value and the motion value to form a final interpolated value for the pixel.