What is motion estimation (ME) in MPEG?

What is motion estimation (ME) in MPEG?

Motion estimation is the process of determining changes in video object positions from one video frame to the next. Object position determination is used extensively in high compression applications. For instance, if the background of a scene does not change but the position of an object in the foreground does, it is advantageous to just transmit the new position of the object rather then the background or foreground. This technology is used in MPEG, H.261, and H.263 compression