Abstract: An image processing/communication system provided with a processing unit for performing a coding processing on image data, a plurality of line memories for storing image data related to the coding processing and coding data, an external-bus connection control unit for controlling a connection between the external bus and the system, an internal bus for transferring data to the processing unit, the external-bus connection control unit and the plurality of line memories, and an operation control unit for causing the processing unit, the plurality of line memories and the external-bus connection control unit to simultaneously perform an input operation of inputting image data from the external bus to the line memory and an output operation of outputting coding data to the external bus from the processing unit or the line memory in parallel with one another. Thus, in each operation of this system, a coding processing can be effected by using the line memory.

Abstract: An image data encoding/decoding apparatus having an encoder and decoder for processing image data such as facsimile data, in which two different streams of image data can be encoded concurrently by using a single encoding circuit section, and two different streams of encoded data can be decoded concurrently using a single decoding section. The encoded data obtained for each scan line portion of the image data are modified, if necessary, to be converted to an integral number of fixed-size amounts of data such as bytes, for subsequent storage in memory. During decoding processing, the encoded data line portions are restored to their respective original forms prior to decoding processing, by controlled operation of registers in which the encoded data are temporarily written in and then serially read out.

Abstract: A data encoding apparatus, applicable for example to a facsimile apparatus, increases the degree of image data compression that can be achieved by a variable length encoding scheme, by limiting the maximum amount of data outputted from the encoding apparatus for each scan line to the amount of unencoded image data in a scan line. Generation of increased amounts of data in the case of certain types of image content, as a result of the variable length encoding, is thereby eliminated with a consequent increase in encoding efficiency.