Bi-directional motion estimation method and apparatus thereof

• US 5,642,166 A
• Filed: 12/29/1994
• Issued: 06/24/1997
• Est. Priority Date: 08/30/1994
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Shi-hwa, Seo, Yang-seock, Shin, Jae-seob
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): LEE, RICHARD J
• Application Number:
  US08/366,096
• Time in Patent Office: 908 Days
• Field of Search: 348/384, 348/390, 348/400-402, 348/407, 348/409-413, 348/415, 348/416, 348/420, 348/699, 382/232, 382/190, 382/195, 382/203, 382/236, 382/238, 382/242, 382/243
• US Class Current: 375/240.15
• CPC Class Codes: H04N 19/20 using video object coding
• CPC Class Codes: H04N 19/537 Motion estimation other than block-based

Abstract

A bi-directional motion estimation method and apparatus thereof in a low bit-rate moving video codec system, for filtering motion vectors by performing a bi-directional motion estimation in units of objects having the same motion in a constant domain and for compensating the motion using the motion vectors generated as the result of forward or backward motion prediction in accordance with the motion prediction mode of previously set frames, can determine the precise motion vector compared to the existing block matching algorithm and depict the inter-frame motion with a smaller amount of information. Therefore, markedly less data (for compression) is used and reconstructed picture quality is improved.

Claims

1. A bi-directional motion estimation method in a low bit-rate moving image codec system, comprising the steps of:

(a) backward estimating the motion of an object in a series of frames having the same motion for the domain where motion is generated at a predetermined block in a frame, and filtering motion information representing the direction in which the object searched in the current frame has moved from the previous frame and shape information of the object;

(b) forward motion estimating for filtering motion information representing the direction in which the object is to be moved in the next frame and index information of the object, using the shape information of the object searched in the current frame by said step (a); and

(c) selectively transmitting the motion information and shape information output in said step (a) or the motion and index information output in said step (b), in accordance with motion estimation modes of previously set frames.

2. A bi-directional motion estimation method as claimed in claim 1, wherein, in said step (c), among consecutive video sequences, only the first frame is transmitted to a receiver stage as an intra-frame, and thereafter, odd frames estimate the motion via a backward prediction mode and even frames estimate the motion via a forward prediction mode.

3. A bi-directional motion estimation apparatus in a low bit-rate moving image codec system, comprising:

backward motion estimation means for estimating the motion of an object in a series of frames having the same motion for the domain where motion is generated at a predetermined block in a frame and for filtering motion information representing the direction in which said object searched in the current frame has moved from the previous frame and shape information of said object;

forward motion estimation means for filtering motion information representing the direction in which said object is to be moved in the next frame and index information of said object, using said shape information of said object searched in the current frame by means of said backward motion estimation means; and

mode and data selection means for selectively transmitting the motion information and shape information output from said backward motion estimation means or said motion and index information output from said forward motion estimation means, in accordance with motion estimation modes of previously set frames.

4. A bi-directional motion estimation apparatus as claimed in claim 3, wherein, in said mode and data selection means, among consecutive video sequences, only the first frame is transmitted to a receiver stage as an intra-frame, and thereafter, odd frames estimate the motion via a backward prediction mode and even frames estimate the motion via a forward prediction mode.