SURVEILLANCE SYSTEM AND METHOD

A surveillance system and method are disclosed. Two images that occur at a certain time apart are captured. The luminance of each pixel for each image is determined. The change in luminance for each pixel is determined. The number of pixels whose change in luminance exceeds a first threshold is calculated. If this number of pixels exceeding a first threshold exceeds a second threshold, the image is stored as the image has sufficiently changed. Since the present image is stored when there is a movement in the present image compared with the previous image, the cost for storing image data is low. Further, when there is a movement, since the time intervals for capturing images are adjusted according to the extent of the movement, the surveillance operation can be carried out effectively.