| 摘要 |
PURPOSE: An adaptive-quantizing apparatus and method for an image encoder are proposed to minimize a change in an adaptive quantization value according to the adaptive quantization value of a current image block with respect to an adaptive quantization value of a previous image block. CONSTITUTION: An adaptive-quantizing apparatus for an image encoder comprises an image analyzer(21) for analysing an activity of an input image, a multiplier(22) for multiplying the image activity obtained from the image analyzer by a quantization value of an output buffer and outputting a result as an adaptive quantization value, and a quantization value output selector(23) for selectively outputting the quantization value. in the apparatus, the adaptive quantization value from the multiplier is compared with the adaptive quantization value of a previous image block to obtain a changing rate of the adaptive quantization value of a current image block, and then comparing the changing rate with a predetermined critical value to selectively output the previous quantization value or the quantization value from the multiplier. |
