Video signal encoding method and system

• US 6,480,670 B1
• Filed: 11/29/1999
• Issued: 11/12/2002
• Est. Priority Date: 03/31/1994
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hasegawa, Hiromu, Shinohara, Takashi, Okazaki, Koji, Mishima, Hidetoshi, Hatano, Yoshiko, Kasezawa, Tadashi
• Primary Examiner(s): BOCCIO, VINCENT F
• Application Number:
  US09/449,494
• Time in Patent Office: 1,079 Days
• Field of Search: H04/N.736, 375/240.12, 375/240.13, 375/240.14, 375/240.15, 375/240.16, 375/240.17, 375/240.21, 375/240.22, 348/677, 348/700, 348/701
• US Class Current: 386/329
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/112 according to a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/142 Detection of scene cut or scene change
• CPC Class Codes: H04N 19/179 the unit being a scene or a shot
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/57 Motion estimation characterised by a search window with variable size or shape
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/87 involving scene cut or scene change detection in combination with video compression
• CPC Class Codes: H04N 5/145 Movement estimation for video coding H04N19/51

Abstract

In an image signal encoding method for encoding an image signal using motion compensation, a motion vector is found by means of a block matching method, a first distortion SEmc of motion compensated prediction associated with the motion vector, and a second distortion SEnomc of prediction without motion compensation are detected, the motion vector is used for for inter-picture prediction encoding when SEnomc>SEmc+K, with K being a constant greater than 0, and a vector having a value zero is used, in place of the motion vector, for inter-picture prediction encoding when SEnomc≦SEmc+K. In another aspect, a speed of motion in a sequence of pictures is detected, and for a part of the sequence of pictures detected to contain a quick motion, the prediction encoding is performed using one-way prediction encoding, and for a part of the sequence of pictures without a quick motion, prediction encoding is performed using bi-directional prediction encoding. In another aspect, the image signal is subsampled for each field, and a motion vector is determined using the field-subsampled image signal.

Claims

1. An image signal encoding method for performing motion compensation inter-picture prediction encoding on an image signal, comprising the steps of:

subsampling the image signal for each field; and

determining a motion vector using the field-subsampled image signal,

wherein the subsampling is conducted such that the picture of said field subsamples maintains a substantially equispaced interlace configuration.

2. The image signal encoding method according to claim 1, wherein a first field and a second field of said subsampled picture maintains a substantially equispaced interlaced configuration between and adjacent to said first field and said second field of said subsampled picture.

3. An image signal encoding method for performing motion compensation inter-picture prediction encoding on an image signal, comprising the steps of:

subsampling the image signal for each field; and

determining a motion vector using the field-subsampled image signal,

wherein the subsampling is conducted such that the picture of the field subsamples has a non-interlace configuration.