Abstract: A pattern data processing apparatus processes pattern data based on which a predetermined pattern is displayed in a display area. The pattern data has data corresponding to both said display area and a data calculating area outside of said display area, the display area being divided into a plurality of pixels.

Abstract: In a color photographic video data conversion system digital data representing each of three primary color components of a pixel is converted (i.e. encoded) to digital data comprising luminance data for the pixel and smoothed (i.e. averaged) chrominance data for a group of contiguous pixels, thereby reducing for transmission the amount of data required to represent picture information. Chrominance data for a group of four pixels in a two-by-two array is selected for smoothing, the human eye being about one quarter as sensitive to color as brightness. When the digital video data is received, the luminance and chrominance data is converted (i.e. decoded) to primary color data comprising data representing satisfactorily each of three primary color components for a pixel. The method of, and apparatus for, both encoding and decoding data in the data conversion system is provided.