Scene-change detection method that distinguishes between gradual and sudden scene changes

• US 5,801,765 A
• Filed: 10/30/1996
• Issued: 09/01/1998
• Est. Priority Date: 11/01/1995
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Gotoh, Yukie, Akahori, Hiroshi, Tatsumi, Toshikazu
• Primary Examiner(s): LIN, BRYAN T
• Application Number:
  US08/739,995
• Time in Patent Office: 671 Days
• Field of Search: 348/700, 348/701, 348/155, 348/154, 348/558, 348/576
• US Class Current: 348/155
• CPC Class Codes: G11B 27/11 by using information not detectable on the record carrier
• CPC Class Codes: G11B 27/28 by using information signals recorded by the same method as the main recording G11B27/22 takes precedence
• 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 19/87 involving scene cut or scene change detection in combination with video compression
• CPC Class Codes: H04N 5/147 Scene change detection

Abstract

A video for one frame is captured and two adjacent frames are compared, the result of which is detected as a change degree of the video. Then, based on the magnitude of the change degree, it is determined whether a scene change (SC) exists. If an SC exists, it is examined whether its change degree alters rapidly or gradually, to determine the SC as a momentum or gradual SC. For the momentum SC, its determination point is detected as the momentum SC. For the gradual SC, its determination points is detected as the start of the gradual SC, thereafter, its end is detected. According, for one gradual SC, plural SC'"'"'s are not detected and a midway illegible video is not indicated as an index picture.

Claims

1. A scene-change detecting method including:

a first step in which a comparison result between a frame picture of input video signals and another frame picture of input video signals, the frames being adjacent to each other, is detected as a video change degree and, if the video change degree is great, it is determined a scene-change exists, wherein the first step determines that there is a scene-chance when a time differential of the video change degree exceeds a prescribed threshold value;

a second step that distinguishes the scene-change determined in the first step between a momentum scene-change and a gradual scene-change, based on a continuity of the video change degree; and

a third step in which for the momentum scene-change determined in the second step, its determined point is detected as the momentum scene-change, and for the gradual scene-change determined in the second step, a period from its determined point to a point at which the video change degree is stable, is detected as a gradual scene-change period.

2. A scene-change detecting method according to claim 1, wherein the first step determines the presence of a scene-change if the video change degree exceeds a prescribed threshold value.

3. A scene-change detecting method according to claim 1, wherein when the second step distinguishes the determined scene-change between a momentum scene-change and a gradual scene-change, provided that a video change degree at a point where the scene-change exists is defined as a first change degree, and a video change degree for at least one frame picture being captured after the first change degree is defined as a second change degree and, if the second change degree is greatly smaller than the first change degree, the above scene-change is determined to be the momentum scene-change, if the difference between the first and second change degrees is small, the above scene-change is determined to be the gradual scene-change.

4. A scene-change detecting apparatus including:

a picture capture means for capturing an input video signal into a frame memory;

a change degree detection means that compares a frame picture captured by the picture capture means with another frame picture captured previously, to detect its comparison result as a video change degree;

a video change degree storage means for storing the video change degree;

a scene-change determination means that determines a scene-change exists if the change degree of the input video exceeds a prescribed threshold value;

a momentum and gradual scene-change determination means that distinguishes the scene-change determined in the scene-change determination means between a momentum scene-change and a gradual scene-change, utilizing the video change degree and a continuity thereof;

the momentum and gradual scene-change determination means detecting a momentum scene-change determination point as the momentum scene-change, and detecting a gradual scene-change determination point as a start point of the gradual scene-change;

a gradual scene-change end detection means in which if the momentum and gradual scene-change determination means determines the above scene-change as the gradual scene-change, a video change degree in a subsequent frame picture captured by the picture capture means is successively input and, a point at which the video change degree holds constant is detected as an end of the gradual scene-change duration;

an index information storage means for storing an index picture of a moving picture and information thereof; and

an index information recording means in which if the momentum and gradual scene-change determination means detects the above momentum scene-change and the gradual scene-change end detection means detects the end of the above gradual scene-change duration, a video signal is input as an index picture, which is then stored in the index information storage means, at the same time, a time counter corresponding the above video signal is recorded as associated information of the index picture, in the index information recording means.