A deinterlacing method based on an edge-directional interpolation in a conversion of video signals of an interlaced scanning format into those of a progressive scanning format, in which the unit of interpolation is extended from the unit of one pixel to the unit of one pixel group. An intermediate frame video is formed from an original interlaced field video. Mismatch values associated Keith edge directions are compared, thereby determining four edge directions exhibiting mismatch values less than those of other edge directions. An interpolation pixel value is calculated, using the intermediate video frame, indices of the four edge directions, and indices of the edge directions. A determination is made based on similarities of the four edge directions, differences among the less mismatch values associated with the four edge directions, and differences of the less mismatch values from mismatch values associated with the remaining edge directions.

A method for edge direction detection at a selected pixel on a center-line between two lines of an image includes defining two vectors using certain pixels on the two lines. A vector norm is defined which gives an indication of the correlation of between pixels of one vector and pixels of the other vector. If a vertical vector norm value indicates a low correlation in the vertical direction, then it can be assumed that the selected pixel is in a non-vertical edge area. Vector norm values associated with small angles from the vertical direction are used to determine candidate directions for the non-vertical edge. If a candidate direction is verified as being a preferred direction, then a direction-fine tuning process is performed in which vector norm values associated with big angles from the vertical direction are calculated in order to find a more accurate direction for the non-vertical edge.

A delay register section 31 holds SD pixels of a luminance signal and a classification section 33 decides a class, reads a coefficient corresponding to the decision result from a coefficient RAM section 40, and outputs the coefficient to a product-sum section 38. The product-sum section 38 captures the pixel data for 17 taps from the delay register section 31, converts the pixel data into seven taps, and outputs them to the product-sum section 38. The product-sum section 38 performs the product-sum operation of pixel data and coefficients and outputs the operation result as HD pixels. An interpolation pixel operation section 42 applies a simple interpolation processing different from the case of a luminance signal to the pixel data of a color signal component to generate HD pixels of a color signal. Thus, downsizing and cost reducing can be realized.

A scanning conversion circuit which interpolates an image signal of an interpolation scanning line from an input image signal Vi of a scanning line adjacent to the upside or downside of an interpolation scanning line to output an image signal Vp doubled in scanning line, and which comprises a directivity detection unit (50) for detecting, in order to prevent an unnatural view of a slant line when a moving image is displayed with an image signal Vp, a direction having the strongest correlation out of a plurality of directions, including a vertical direction and a slant direction, centering on an interpolation point of an interpolation scanning line based on the signal Vi, and an average value computing unit (56) for computing an average value of image signals at two sampling points corresponding to the detected direction out of a plurality of sampling points in an upside scanning line and downside scanning line. When the directivity detection unit (50) judges that a slant-direction correlation is the strongest, the average value computing unit (56) computes an average value of image signals at corresponding and slant-direction two sampling points in an upside scanning line and downside scanning line to process the value as an image signal of an interpolation scanning line, thereby permitting a proper interpolation processing an a slant line in a moving image.

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, includes generating a motion value representative of the motion between successive frames about the pixel, detecting an edge direction about the pixel, performing an edge adaptive interpolation at the pixel, using the detected edge direction, and performing a motion adaptive interpolation at the pixel, using the generated motion value. Apparatus 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, includes a motion value generator configured to generate a motion value representative of the motion between successive frames about the pixel, an edge direction detector configured to detect an edge direction about the pixel, an edge adaptive interpolator configured to perform an edge adaptive interpolation at the pixel, using the detected edge direction, and a motion adaptive interpolator configured to perform a motion adaptive interpolation at the pixel, using the generated motion value.