Motion estimation techniques for digital TV: a review and a new contribution

Abstract

The key to high performance in image sequence coding lies in an efficient reduction of the temporal redundancies. For this purpose, motion estimation and compensation techniques have been suc cessfully applied. This paper studies motion estimation algorithms in the context of fi rst generation coding techniques commonly used in digital TV. In this framework, estimating the motion in the scene is not an intrinsic goal. Motion estimation should indeed provide good temporal prediction and simultaneously require low overhead information. More specifically, the aim is to minimize globally the bandwidth corresponding to both the prediction error information and the motion parameters. This paper first clarifies the notion of motion, reviews classical motion estimation tech niques, and outlines new perspectives. Block matching techniques are shown to be the most appropriate in the framework of first generation coding. To overcome the drawbacks characteristic of most block matching techniques, this paper proposes a new locally adaptive multigrid block matching motion estimation technique.This algorithm has been designed taking into account the above aims. It leads to a robust motion field estimation, precise prediction along moving edges and a decreased amount of side information in uniform areas. Furthermore, the algorithm controls the accuracy of the motion estimation procedure in order to optimally balance the amount of information corresponding to the prediction error and to the motion parameters. Experimental results show that the technique results in greatly enhanced visual quality and significant saving in terms of bit rate when compared to classical block matching techniques.

Filtering of Block Motion Vectors for Use in Motion-Based Video Indexing and Retrieval

“…Although it is an effective method, it is computationally intensive and very complex. The OFE method also does not cope well with high motion video sequences [7].…”

Hierarchical Motion-Compensated Frame Rate Up-Conversion Using Gaussian Pyramid and Guidance Motion Vector

“…ME is the process that finds motion vector (MV). There are many ME algorithms but block matching algorithm (BMA) is mainly used because it is easy to implement both in software and hardware [2]. BMA finds the MV by finding the block that is most similar to the current block in the search range.…”

Block-based motion estimation algorithms — a survey

“…Due to its simplicity and efficiency [1], block−based ME (BBME) [2] has been adopted in several international video coding standards such as MPEG−x, H.26x, and VC−1 [3,4]. In BBME, the current frame is divided into N×N− −pixel−size macroblocks (MBs) and for each MB a certain area of the reference frame is searched to minimize a block difference measure (BDM), which is usually a sum of abso− lute differences (SAD) between the current and the refer− ence MB.…”