Patent ID: 8072540

Claim:
An apparatus of low angle interpolation for generating an interpolated scan line between a first scan line and a second line of a field, the apparatus comprising: a low angle calculation circuit for receiving all luminance values of the first scan line and of the second scan line, calculating and comparing sums of absolute differences (SADs) of all angles of each pixel in the interpolated scan line and generating a plurality of operating parameters of each pixel in the interpolated scan line based on a counterclockwise operating matrix and a clockwise operating matrix; a line buffer for storing final interpolation directions of all pixels of the preceding interpolated scan line; a direction decision circuit coupled to the line buffer and the low angle calculation circuit for determining a temporary interpolation angle of each pixel in the interpolated scan line based on the operating parameters of each pixel in the interpolated scan line and the final interpolation directions of all the pixels of the preceding interpolated scan line; a post-processing circuit coupled to the line buffer and the direction decision circuit for performing calibration on the interpolation direction and determining a final interpolation angle and the final interpolation direction of each pixel in the interpolated scan line based on the temporary interpolation angles of all the pixels in the interpolated scan line and the final interpolation directions of all the pixels of the preceding interpolated scan line; and an interpolator coupled to the post-processing circuit for receiving the final interpolation angle of each pixel of the interpolated scan line, both the luminance values and chrominance values of all pixels in the first scan line, and both the luminance values and the chrominance values of all pixels in the second scan line, and performing interpolation corresponding to either the final interpolation angle or 90 degrees depending on an absolute chrominance error of each pixel in the interpolated scan line so as to obtain the luminance value and the chrominance value of each pixel in the interpolated scan line; wherein each of the final interpolation angle and the temporary final interpolation angle comprises the interpolation direction information.