1. A method for identifying possible tampering of a camera view, said method comprising: receiving an image for analysis from an image sequence, converting the received image into an edge image, generating a similarity value indicating a level of similarity between said edge image and a reference edge image, indicating possible tampering of the camera view if the similarity value is within a specified tampering range, updating the reference edge image by combining a recently analyzed edge image with the reference edge image in case of each one of a predetermined number of consecutively analyzed images does not result in an indication of possible tampering, counting the number of consecutively analyzed images resulting in an indication of possible tampering, and generating an alarm signal in case of each one of a predetermined number of consecutively analyzed images does result in an indication of possible tampering, wherein said predetermined number is larger than one.