Fixed length cell handling type image communication method as well as transmission apparatus for fixed length cell handling type image communication and reception apparatus for fixed length cell handling type image communication

A fixed length cell handling type image communication method wherein image data are communicated in fixed length cells each including a header part and a data part, comprising the steps of:

• receiving, from a network, fixed length cells each including fixed length data obtained by dividing each piece of variable length data representing moving picture data in transmission end, which moving picture data defines information of a plurality of screens individually divided into a plurality of fields and compressed for every field serving as a transmission unit using an intra-field compression, and residual information, between transmission rate information based on a basic sampling clock representative of a compression of the each field and network clock information of the network, for transmission using header parts of particular fixed length cells;
• regenerating the individual fixed length data by removing the header part of the received individual cells and the basic sampling clock based on the network clock information and the received residual information;
• converting, based on the regenerated basic sampling clock, the plural pieces of regenerated fixed length data-into variable length data in each field is independent of that in each other field;
• decompressing the variable length data based on the regenerated basic sampling clock, using an intra-field decompression method for still picture decompression, to regenerate the original moving picture data;
• wherein
• each time the still picture compression processing for any field is performed in the transmission end, a compression ratio for the still picture compression processing is adjusted so that a compressed image data amount per each unit field of the variable length data obtained is within a predetermined range.

A reception apparatus for fixed length cell handling type image communication wherein image data are transmitted as fixed length cells each including a header part and a data part, comprising:

• a fixed length cell reception section for receiving fixed length cells from a network each including fixed length data obtained by dividing each piece of variable length data representing moving picture data in transmission end, which moving picture data define information of a plurality of screens individually divided into a plurality of screens individually divided into a plurality of fields and compressed for every field serving as a transmission unit using an intra-field compression method for still picture compression, and residual information, between transmission rate information based on a basic sampling clock representative of a compression of the each field and network clock information of the network, for transmission using header parts of particular fixed length cells and regenerating the individual fixed length data by removing the header part of the received individual cells and the basic sampling clock based on the network clock information and the received residual information;
• a reception buffer section for converting, on the basis of sampling clock regenerated by said fixed length cell reception section, the plural pieces of regenerated fixed length data into variable length data which in each field is independent of that in each other field;
• an image data decompression section for decompressing the variable length data from said reception buffer section based on the regenerated basic sampling clock, using an intra-field decompression method for still picture decompression to regenerate the original moving picture data;
• wherein
• each time the still picture compression processing for any field is performed in the transmission end, a compression ratio for the still picture compression processing is adjusted so that a compressed image data amount per each unit field of the variable length data obtained is within a predetermined range.

A fixed length cell handling type image communication method wherein image data are communicated in fixed length cells each including a header part and a data part, comprising the steps of:

• compressing moving picture data, which define information of a plurality of screens individually divided into a plurality of fields to be transmitted per unit time, for every field serving as a transmission unit using an intra-field compression method for still picture compression to convert the moving picture data into variable length data, which in each field is independent of that in each other field;
• dividing each piece of the variable length data into a plurality of pieces of fixed length data;
• generating fixed length cells, each having a respective piece of said fixed length data as the data part, for transmission to a network;
• sending the plurality of said fixed length cells and residual information, between transmission rate information based on a basic sampling clock representative of a compression of the individual field and network clock information of the network, using header parts of particular fixed length cells to perform transmission to the network of the moving picture data;
• wherein
• each time the still picture compression processing for any field is performed, a compression ratio for the still picture compression processing is adjusted so that a compressed image data amount per each unit field of the variable length data obtained is within a predetermined range.