IMAGE CHANGE DETECTOR, ITS DETECTING METHOD AND STORAGE MEDIUM THEREOF

摘要

PROBLEM TO BE SOLVED: To detect the presence of a change in an image without using frame memory. SOLUTION: A selection circuit 20 selects an either output video signal from camera units 12A, 12B and the selected signal is fed to a coding circuit 24 via an A/D converter 22. An output image of the A/D converter 22 is compressed by the JPEG method. A counter 30 counts quantity of codes in an output bit stream from the circuit 24 and gives the counted result to a distribution circuit 32. The circuit 32 gives the counted results, with respect to the output images from the camera units 12A, 12B respectively to registers 34, 38 and comparator circuits 36, 40. The registers 34, 38 hold the code quantities and the counted values of the last time and give them to the circuit 36, 40. The circuits 36, 40 compare the code quantities from the registers 34, 38 and the circuit 32 and detection circuits 42, 44 output an image distribution request to a control circuit 46, when the results of comparison by the circuits 36, 40 are higher than a prescribed value.