| 摘要 |
PURPOSE:To improve picture quality by measuring the fineness of the input television signal of a block to be intraframe-coded, and making quantization step size small for the block whose average value is larger than a definite value, and in addition, which is fine in a continuous block group to be quantized by the same quantization step size. CONSTITUTION:The fineness of every block the luminance signal of the input television signal has is measured. Then, as for the block which is the contiuous block to be quantized by first quantization step size 24 to be the same standard, and has a fine picture, the average value of whose picture element value is larger than the definite value, an orthogonal transformation factor 18 is quantized by second quantization step size 20 which is the first quantization step size 24 made small according to the average and the variance of the picture element value of the corresponding block and a threshold corrected by the first quantization step size 24. Thus, the improvement of the picture quality of the block with the fine picture can be attained while limiting the quantity of generated codes. |
