| 摘要 |
PURPOSE:To set a substantial average speed to a setting speed and to improve the quality of a picture by controlling the quantity of generated information not in a frame unit but controlling that the cumulative value of the information quantity for a prescribed period becomes constant. CONSTITUTION:A cumulative count circuit 12 counts the quantity of generated information for a prescribed period, and inputs the value to a comparison circuit 13. On the other hand, a speed which is set in a setting circuit 8, and the quantity of information cumulated in a holding and turning circuit 14 are inputted to the circuit 13. If the input value of the circuit 12 is bigger than that of the circuit 14, a threshold is controlled in a direction to be enlarged, and if it is opposite, in the direction to be minimized. The period of updating the threshold is set to be that of cumulating the quantity of information in the circuit 12. If the compared difference of the circuit 13 becomes below a prescribed value, updating is stopped. A motion detection circuit 2 holds the threshold and executes the coding of the picture. Thus, the quality of the picture is improved with setting the substantial average speed to the setting speed. |
