METHOD AND DEVICE FOR HIGH EFFICIENCY ENCODING

摘要

PURPOSE:To improve encoding efficiency irrespective of the comression rate in variable length encoding with high efficiency where data obtained by converting picture data into a frequency area is quantized. CONSTITUTION:Weighings with an object to improve encoding efficiency at respective low comression rates in a weighing circuits 5a and 5b and with the object to improve encoding efficiency at high comression rate are conducted to conversion data obtained by converting inputted picture data into the frequency area by a converting circuit consisting of a block converting circuit 2 and a DCT circuit 3. Then, a bit number at the time of quantizing and variable length encoding in an encoding quantity estimating circuits 12a and 12b is calculated and a quantization characteristic deciding circuit 8 decides a quantization characteristic which is predicted to obtain encoding quantity being close to the target bit number. Quantization is conducted by a quantizing circuit 9 through the use of the quantization characteristic and variable length encoding is conducted in an encoding circuit 10.