CODING DECODING METHOD FOR PICTURE INFORMATION

• Main Author: MAEZAWA YOSHIMASA
• Format: Patent
• Language: English
• Published: 25.11.1994
• Edition: 5
• 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 efficient coding processing even for a picture with a large average level by implementing coding while an averaged level in a block is used for a difference from an average level of input picture information in the case of conversion coding in the unit of blocks. CONSTITUTION:Picture information subject to block processing by a block processing unit 1 is subject to 2-dimensional orthogonal transformation by an orthogonal transformation device 2 and an orthogonal transformation coefficient is provided as an output. The orthogonal transformation coefficient is inputted to a subtractor and a data selector of a quantization device/code allocation device 3. Average level information obtained by an average level counter 5 is inputted to other input of the subtractor. The average level information is subtracted from the inputted orthogonal transformation coefficient in the subtractor to obtain a difference from an average level, An output from the data selector selecting a DC component and an AC component in the orthogonal transformation coefficient is received by the quantizer, in which the output is quantized and the information quantity is controlled by a code allocation device and the result is provided as an output as compressed information.