IMAGE CODER

• Main Authors: YAMASHITA NOBUITSU, TAKAHASHI KOJI, ROTSUPONGI NOBUKUNI
• Format: Patent
• Language: English
• Published: 02.06.1995
• Edition: 6
• Subjects: BASIC ELECTRONIC CIRCUITRY; CALCULATING; CODE CONVERSION IN GENERAL; CODING; COMPUTING; COUNTING; DECODING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION

PURPOSE:To attain highly efficient coding without using a complicated circuit by sampling a received digital image signal and selecting a 1st compression coding mode on a difference signal obtained by subtracting a predicted value from the obtained image signal or selecting a 2nd compression coding mode without using the difference signal. CONSTITUTION:A difference outputted from a subtractor circuit 8 is inputted to a discrete cosine transformation circuit 11 via a data quantity comparator circuit 9 and a changeover switch 10, and quantized block data are converted into linear data strings and they are given to a variable length coding circuit 13. Coded data subject to variable length coding are inputted to a buffer memory 14, in which image data are converted at a prescribed rate, the data are give to a multiplexed circuit 15, where quantized information data are multiplexed onto the image data by using an output from a system control circuit 16, and the multiplexed data are provided as an output from an output terminal 17. Namely, when quantization of block data of a 1st field is finished, block data of a 2nd field are processed and coding for one frame is processed while repeating the above-mentioned processing.