Patent ID: 7259794

Claim:
An edge-based method for de-interlacing an image, which comprises a target pixel, a first pixel positioned at an upper-left side of the target pixel, a second pixel positioned above the target pixel, a third pixel positioned at an upper-right side of the target pixel, a fourth pixel positioned at a lower-left side of the target pixel, a fifth pixel positioned below the target pixel, and a sixth pixel positioned at a lower-right side of the target pixel, the method being for calculating a brightness value of the target pixel, the method comprising the steps of: calculating a horizontal coefficient and a vertical coefficient according to brightness values of the first to sixth pixels; determining an edge type of the target pixel, wherein the edge type of the target pixel is a smooth region if the horizontal and vertical coefficients are smaller than a horizontal threshold value and a vertical threshold value respectively, the edge type of the target pixel is a vertical edge if the horizontal coefficient is smaller than the horizontal threshold value and the vertical coefficient is greater than the vertical threshold value, the edge type of the target pixel is a horizontal edge if the horizontal coefficient is greater than the horizontal threshold value and the vertical coefficient is smaller than the vertical threshold value, and the edge type of the target pixel is an inclined edge if the horizontal and vertical coefficients are greater than the horizontal and vertical threshold values respectively; determining a plurality of reference pixels according to the edge type of the target pixel; and calculating the brightness value of the target pixel according to the reference pixels.