CAMERA BLOCK DETECTION SYSTEM

PROBLEM TO BE SOLVED: To easily recognize various blocking actions to a surveillance camera. SOLUTION: An image of the surveillance camera 1 is compared with a reference image to calculate a difference of luminance in each pixel. If a luminance difference value is equal to or greater than a first threshold, the pixel is defined as a changed pixel. When changed pixels are generated equally to or more greatly than a second threshold in a full screen, it is checked whether to be a sudden image change. In the case of being a sudden image change, it is checked whether to be such a single color blocking action to cover the camera and create only one black or such a mixed change blocking action to change the direction of the camera and change the entire image, and the type of a camera blocking action is attached to make a warning. In the case of not being the sudden image change, it is checked whether to be a foreign matter intrusion, and in the case of being a foreign matter intrusion, a warning is made. In the case of being neither the single color blocking action nor the mixed change blocking action, it is determined to be an illumination change or the like. Thus, a camera blocking action such as to cover the surveillance camera can be determined only by image processing while distinguishing it from the other causes. COPYRIGHT: (C)2008,JPO&INPIT