Method for Reducing Pulsation in MPEG Video Coding
Original Publication Date: 2002-Jan-29
Included in the Prior Art Database: 2003-Jun-20
Method For Reducing Pulsation In MPEG Video Coding Larry Lu, Jack Kouloheris, Cesar Gonzales What is disclosed is a rate control scheme that can be used to prevent the pulsation artifact in MPEG still scene video coding. Pulsation in MPEG video coding of still scenes is an annoying artifacts. In a still scene, each picture has the same signal characteristics. (There may be some noise, however it is often negligible in most cases.) Ideally, such still scene should be encoded consistently. However, if any portion of the picture is not coded consistently throughout the sequence, it may produce pulsing artifacts. Furthermore, MPEG video encoders typically code the incoming pictures with different coding types according to a pre-selected pattern, for example, the size of group of pictures (GOP) N=15 and the reference picture distance M=3. Therefore, when the video source changes from motion scene to still scene, whether there will be pulsation artifacts will largely depend on the encoder's rate control scheme. Since the pulsing artifact means that the picture qualities over the scene are not consistent, it implies that the bit allocation algorithm is not functioning appropriately. Therefore to eliminate the pulsation artifacts, we must consistently distribute the bits over same type of pictures and manage the VBV buffer at appropriate level to prevent any inconsistent bit allocation.