Patent ID: 8237858

Claim:
A scanning line interpolating device comprising: an interpolation processing unit for determining a pixel value of an interpolation-target pixel based on pixel values of at least two pixels located in a diagonal direction from the interpolation-target pixel; an interpolation value limiting unit for compensating the pixel value determined by the interpolation processing unit such that the pixel value of the interpolation-target pixel becomes a value between pixel values of two adjacent pixels above and below the interpolation-target pixel, when the pixel value determined by the interpolation processing unit is outside an interval between the pixel values of the two adjacent pixels above and below the interpolation-target pixel; and a false operation preventing unit for preventing false operations of the interpolation value limiting unit by selectively outputting, as an interpolated video signal, the pixel value determined by the interpolation processing unit or the pixel value compensated by the interpolation value limiting unit, based on a pixel value of a pixel on a scanning line above the interpolation-target pixel and a pixel value of a pixel on a scanning line below the interpolation-target pixel, wherein the false operation preventing unit includes: an intersection area detecting unit for judging whether or not the interpolation-target pixel is located in an intersection area which is, when the horizontal axis represents a horizontal position and the vertical axis represents a pixel value, an area in proximity of a horizontal position where a curve line, representing pixel values of pixels on the scanning line above the interpolation-target pixel, and a curve line, representing pixel values of pixels on the scanning line below the interpolation-target pixel, intersects; and a selecting unit for, depending on the judgment result of the intersection area detecting unit, outputting, as the interpolated video signal, the pixel value compensated by the interpolation value limiting unit when the interpolation-target pixel is judged not to be located in the intersection area, and for outputting, as the interpolated video signal, the pixel value determined by the interpolation processing unit when the interpolation-target pixel is judged to be located in the intersection area.