An architecture for video compression based on the SCAN algorithm

The SCAN methodology is a class of formal languages which can be applied to compression, encryption, and data hiding or in combinations thereof. The SCAN algorithm for video compression belongs to the category of interframe techniques. Each frame is compared to its preceding one and through frame differencing redundant information is removed. As in all algorithms of this category key frames are placed as beginning points for finding the differences with subsequent frames. Frames between key frames are named difference frames and they only contain the information that has changed from the previous frame. The differences between frames are determined using a user-defined threshold value, and therefore in general this type of compression can be lossy. The consequent degradation of picture is controlled by the user via the choice of threshold value. When this threshold is 0 the compression becomes lossless. The final goal is to develop a seamless architecture for compression, encryption and information hiding.