A receiving processing unit receives identical SD pictures transmitted a plurality of number of times, and performs addition for weighting an SD picture stored in a storage and the received SD pictures. The receiving processing unit stores the obtained values as a new SD picture in the storage. A picture-quality determining unit determines the picture quality of the new SD picture stored in the storage, and based on the determined picture quality, a request-signal transmitting unit requests class codes representing classes obtained by classifying the pixels of an HD picture in which the quality of an SD picture is increased. A receiving-control unit receives class codes which are transmitted in response to the request, and based on the SD picture and the class codes, an adaptive processing unit calculates predicted values of an HD picture corresponding to the SD picture.

A color conversion method for preferred color tones to change original color in a color image into a preferred one. The invention first sets chromaticity of the selecting original color and corresponding preferred color, then takes them as the basic points to establish a tone action space of the two color according to a color tone action distance. The two spaces are then joined to form a color conversion space and to determine a vector from the original color to the preferred color for converting the colors in the color conversion space into the new color. Finally, the color conversions from the original color to the new color are made to generate a new color image with the preferred color tone. The invention only converts the original colors in the color conversion space into new colors to get a new color image with preferred color tones. The selecting original color and corresponding preferred color pair can be plural in the invention.

An image processing circuit capable of carrying out high-speed processing and improving the horizontal and vertical resolutions even with its simple structure. The pixel values a to i of a total of nine pixels, three pixels in the horizontal direction along a scanning line by three pixels in the vertical direction in which the line and adjacent lines are abreast, are extracted by a pixel value extracting section. The pixel values A1 to A4 of four pixels Q1 to Q4 generated additionally around the center pixel P5 are determined by calculation by a pixel value calculation section. These pixel values are outputted in units of one scanning line by correlating them with two scanning lines by a pixel value output section.

An output pixel datum is produced from input pixel data by a method wherein the brightness levels of several input pixels closely associated coordinate-wise with the output pixel, are examined to determine whether a relatively less complex graphics-optimized scaling procedure, or a relatively more sophisticated video-optimized scaling procedure, should be carried out. In the second case, directional interpolation is performed with a plurality of directions, e.g., being considered to determine the direction of minimum brightness level gradient. A plurality of intermediate pixels, e.g., four, are produced, which are aligned perpendicularly to the minimum brightness level gradient direction, their brightness levels being determined from relevant input pixels using linear interpolation. The output pixel brightness level is determined from the intermediate pixels through the use of an appropriate filtering technique, e.g., polyphase FIR filtering. An apparatus for performing the method and a system incorporating the apparatus, are described.

An output pixel datum is produced from input pixel data by a method wherein the brightness levels of several input pixels closely associated coordinate-wise with the output pixel, are examined to determine whether a relatively less complex graphics-optimized scaling procedure, or a relatively more sophisticated video-optimized scaling procedure, should be carried out. In the second case, directional interpolation is performed with a plurality of directions, e.g., being considered to determine the direction of minimum brightness level gradient. A plurality of intermediate pixels, e.g., four, are produced, which are aligned perpendicularly to the minimum brightness level gradient direction, their brightness levels being determined from relevant input pixels using linear interpolation. The output pixel brightness level is determined from the intermediate pixels through the use of an appropriate filtering technique, e.g., polyphase FIR filtering. An apparatus for performing the method and a system incorporating the apparatus, are described.