| 摘要 |
<p>PURPOSE:To improve a picture quality by executing the setting of a threshold so as to conserve the frequency components of a low band as possible in consideration for the visual characteristic of a human. CONSTITUTION:The encoder is equipped with a cosine transformation part 1, a threshold processing part 2, a quantization processing part 3, a variable length encoding part 4, and a buffer part 5 for adjusting the speed. The threshold is set higher as the group of the coefficient of a high-order with a comparatively small amplitude (power), and as to the coefficient at the threshold or below, the value is managed as zero. Thus, the generation rate of a zero run is increased, the encoding efficiency is improved, and even in the case of a low bit rate encoding, the image to be visually suitable can be obtained.</p> |
