Patent ID: 8571097

Claim:
A picture coding and decoding system comprising a picture coding apparatus and a picture decoding apparatus, wherein said picture coding apparatus comprises: a picture coding unit operable to code a picture signal; a ratio coding unit operable to code a ratio of a number of luminance pixels to a number of chrominance pixels for the picture signal; a selecting unit operable to select one coding method out of at least two coding methods, the one coding method being selected based on the ratio; and a data coding unit operable to code data related to a picture size in accordance with the selected coding method, wherein the data related to the picture size indicates a size of a picture corresponding to the picture signal, wherein, when a ratio of a number of horizontal luminance pixels to a number of horizontal chrominance pixels is M:1, said selecting unit selects a coding method coding 1/M of a number of horizontal pixels, the horizontal luminance pixels and the horizontal chrominance pixels being included in the picture signal, wherein said picture decoding apparatus comprises: a picture decoding unit operable to decode a coded picture signal; a ratio decoding unit operable to decode the ratio of the number of luminance pixels to the number of the chrominance pixels for the decoded picture signal; a selecting unit operable to select one decoding method out of at least two decoding methods, the one decoding method being selected based on the ratio; and a data decoding unit operable to decode data related to the picture size in accordance with the selected decoding method, wherein the data related to the picture size indicates a size of a picture corresponding to the decoded picture signal, and wherein, when the ratio of the number of horizontal luminance pixels to the number of horizontal chrominance pixels is M:1, said selecting unit of said picture decoding apparatus selects a decoding method where a parameter value of a horizontal size included in the decoded data related to the picture size is multiplied by M, the horizontal luminance pixels and the horizontal chrominance pixels being included in the decoded picture signal.