Modified one-bit transform method with dynamic search range

Abstract

Abstract. Here, a new low-complexity block motion estimation method is presented. The proposed method significantly reduces the computational complexity by checking only one of two search areas in the conventional hybrid method when the two search centers are close to each other. It also improves the performance by efficiently making use of the motion vector information of the co-located macroblock. The proposed techniques can be easily applied to many hybrid motion estimation methods. IntroductionMotion estimation is an essential part of most video coding standards. Although the full search (FS) method gives the best performance, it incurs enormous computational complexity. Thus, many low-complexity motion estimation algorithms have been proposed, including the one-bit transform (1BT), two-bit transform (2BT), and constrained 1BT (C1BT) methods.1-3 These low-complexity methods greatly reduce the complexity, but they lead to very low peak signalto-noise ratio (PSNR) values. In order to solve this problem, many hybrid methods have been proposed that combine the low-complexity methods with the FS method. For example, the modified 1BT (M1BT) method combines the 1BT method with the FS method. 4 The modified 2BT (M2BT) and modified C1BT (MC1BT) methods also combine lowcomplexity methods with the FS method. 5,6 This paper proposes an efficient search scheme that not only reduces the complexity, but also improves the performance of these conventional hybrid methods.