Methods and apparatus for transmitting picture data, processing pictures and recording media therefor

摘要

A data processing system wherein picture data in which there is allocated a value representing transparency as a pixel value is transmitted after being compressed in terms of picture data corresponding to a pre-set pre-determined size of a picture area as a unit. Ancillary data specifying whether each pixel of the original picture data of the picture data unit is transparent or opaque is transmitted in correlation with the compressed picture data as the unit. On expansion of the compressed picture data, a pixel set as a transparent pixel by the ancillary data is compulsorily set as a transparent pixel without regard to the expanded picture data.