OPTIMAL INTER-FRAME ALIGNMENT FOR VIDEO COMPRESSION

Abstract

Quite often a camera that is shooting a video sequence swings or rocks (for example the camera is hand held). For compression of digitized video it can be important to compensate for the motion of the camera by realigning the frames, shifting them one respect to the other, absorbing the movement of the camera. We show that for the general version of optimal frame alignment, the Vector Alignment problem is NP-complete. Moreover we prove that the Run Length Coding Alignment problem, a restricted subcase of the Vector Alignment problem that has direct application in video compression, can be solved in linear time by a dynamic programming algorithm.