| 摘要 |
PURPOSE:To upgrade information for detecting the change of a picture and to reduce the burden of the person monitoring pictures with appropriate discrimination by issuing alarm with comparing a reference screen with a monitoring picture and finding any change in the monitoring picture and by comparing the information of the picture in which changed was found and transmitting it in narrow band mode. CONSTITUTION:The cumulatively added value calculated by projective operator circuit 16 corresponding to the standard screen made of primary extraction reference data D1i and the current picture is compared with the decision reference value, and when the cumulatively added value exceeds the decision reference value, the decision is made that the change between the previous screen and the current screen is not normal, and on the contrary when the cumulatively added value does not exceed the decision reference value, the decision is made that the change between the change between the previous screen and the current screen is normal. Picture data within the region of this change is sent to encoder circuit 21 via data compression circuit 20, and the picture data is compressed, encoded, and is transmitted in the narrow band mode through a telephone line L via a modem 23 and an NCU24 under the control of a transmission controller 22. Since the volume of the change exceeds the decision reference value, the alarm is issued, thereby being able to securely identify and discriminate the normal change such as an illumination change due to insolation from an abnormal change and to upgrade change detection accuracy. |
