In
video compression, motion compensation is a technique for describing a picture in terms of translated copies of portions of a reference picture, often 8x8 or 16x16-pixel blocks. This increases compression ratios by making better use of redundant information between successive frames. A simple block replacement scheme would successfully compress only those portions of the screen that do not move. However when the block in a new frame and a previous frame are not similar, it is often the case that the information contained in the new frame's block is, in fact, available in the previous frame - but it has moved. Consider a car moving across the screen. Even though it has moved from one frame to the next, much of the data required for the latest frame is still in the previous frame, just not in the same place. Motion compensation attempts to achieve greater compression by reusing portions from the previous frame to construct the new frame, even if they have moved.
See more at Wikipedia.org...
Interframe
coding that (a) is used to compress motion of
video images and (b) uses an algorithm to examine a
sequence of image frames to measure the difference from
frame to frame in order to send motion vector
information. (
188 )
Free Download Now!
