| 摘要 |
<p>PURPOSE:To effectively prevent the generation of a frame missing by surely detecting a scene change and suppressing the amount of encoded data in a moment. CONSTITUTION:In a subtractor 32, the image signal corresponding to the n-th one frame inputted from a buffer memory 2 is subtracted every pixel element corresponding to the image signal of the (n-1)th frame read out of a frame memory 34 and the value of the difference is taken out. In a numerical converter 36, the value of this difference is threshold processed by defining a preliminarily set threshold as a boundary and the number of '1' of the binary value is counted one frame by one frame in a counter 38. A CPU 12 reads out the count value from the counter 38 and the change ratio of an image is calculated. In an encoding controller 10, the image signal is converted into the control signal corresponding to the change ratio in accordance with a preliminarily set function and the quantization level Q of a video encoder is controlled by this control signal. Thus, the scene change at the time of an image transmission is surely detected and the amount of encoded data is suppressed by roughing a quantization step momentarily.</p> |
