Scene-change-point detecting method and moving-picture editing/displaying method

• US 6,025,886 A
• Filed: 08/20/1997
• Issued: 02/15/2000
• Est. Priority Date: 08/20/1996
• Status: Expired due to Term

• Current Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Koda, Eriko
• Primary Examiner(s): BRITTON, HOWARD W
• Application Number:
  US08/914,810
• Time in Patent Office: 909 Days
• Field of Search: 348/700, 348/701, 386/4, 386/52
• US Class Current: 348/700
• 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 19/50 using predictive coding H04N19/61 takes precedence
• CPC Class Codes: H04N 19/507 using conditional replenishment
• 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 method, apparatus and computer program for detecting a scene change point in a moving picture which has been coded according to a moving-picture coding process. The moving picture coding process divides the processing picture into a plurality of pictures. Each picture is divided into a plurality of blocks each being compressed by an encoder. The encoder operates according to a selected one of three compression techniques, namely an intra-picture compression technique, a differential-picture compression technique or a skipped-block compression technique. The invention counts the number of blocks of each picture subjected to the compression techniques, records the counts as user data, and analyzes the counts stored in the user data in a decoding operation in order to detect a scene change point of the moving picture.

Claims

1. A scene-change-point detecting method for detecting a scene change point in a moving picture which has been coded according to a moving-picture coding process of dividing said moving picture into groups of pictures each having a first picture to undergo intra-picture compression, a plurality of second pictures each to undergo forward differential-picture compression, wherein differences between each second picture and a timewise preceding encoded picture are compressed and a plurality of third pictures each to undergo forward/backward differential-picture compression wherein differences between each third picture and a timewise preceding encoded picture and a timewise succeeding encoded picture are compressed, dividing each of said pictures into blocks each having a predetermined size, and encoding each of said blocks by one of said intra-picture compression, said forward differential picture compression arid said forward/backward differential picture compression, said scene-change-point detecting method comprising the steps of:

counting the number of blocks in a picture completing said differential-picture compression, counting the number of blocks in said picture completing said intra-picture compression and counting the number of blocks in said picture completing no compression; and

detecting whether a scene change point exists in said picture based on the counts.

2. A scene-change-point detecting method according to claim 1, wherein said detecting step comprises the step of:

determining a scene-change-point by comparing the count of the number of blocks in said picture completing said intra-picture compression to a threshold value.

3. A scene-change-point detecting method according to claim 1, wherein information required for detection of a scene change point including the counts are recorded as user data.

4. A moving-picture editing/displaying method for editing and displaying a moving picture by decoding, editing and displaying a stored, compressed and coded moving picture, said moving picture being coded according to a moving-picture coding process of dividing said moving picture into groups of pictures each having a first picture to undergo intra-picture compression, a plurality of second pictures each to undergo four differential-picture compression, wherein differences between each second picture and a timewise preceding encoded picture are compressed, and a plurality of third pictures each to undergo forward/backward differential-picture compression, wherein differences between each third picture and timewise proceeding encoded picture and a timewise succeeding encoded picture are compressed, dividing each of said pictures into blocks each having a predetermined size, and encoding each of said blocks by one of said intra-picture compression, said forward differential picture compression and forward/backward differential picture compression, said moving-picture editing/displaying method comprising the steps of:

specifying a picture position in said moving picture;

searching said moving picture for said specified picture position in a process of decoding said stored, compressed and coded moving picture;

detecting a scene change point preceding said picture position and a scene change point succeeding said picture position, said detecting step comprises the steps of;

counting the number of blocks in a picture completing said differential-picture compression, counting the number of blocks in said picture completing said intra-picture compression, and counting the number of blocks in said picture completing no compression, and

detecting whether a scene-change-point exists in said picture based on the counts; and

displaying pictures starting with a picture at said scene change point preceding said picture position and ending with a picture at said scene change point succeeding said picture position.

5. A moving-picture editing/displaying method according to claim 4, wherein information required for detection of a scene change point including the counts are recorded as user data.

6. A moving-picture editing/displaying method according to claim 4, wherein said detecting step comprises the step of:

determining a scene-change-point by comparing the count of the number of blocks in said picture completing said intra-picture compression to a threshold value.

7. A scene-change-point detection apparatus for detecting a scene change point in a moving picture which has been coded by a moving-picture compression system according to a moving-picture coding process of dividing said moving picture into groups of pictures each having a first picture to undergo intra-picture compression, a plurality of second pictures each to undergo forward differential-picture compression, wherein differences between each second picture and a timewise preceding encoded picture are compressed and a plurality of third pictures each to undergo forward/backward differential-picture compression wherein differences between each third picture and a timewise preceding encoded picture and a timewise succeeding encoded picture are compressed, dividing each of said pictures into blocks each having a predetermined size, and encoding each of said blocks by one of said intra-picture compression, said forward differential picture compression and said forward/backward differential picture compression, said scene-change-point detection apparatus comprising:

means for counting the number of blocks in a picture completing said differential-picture compression, counting the number of blocks in said picture completing said intra-picture compression and counting the number of blocks in said picture completing no compression; and

means for detecting whether a scene change point exists in said picture based on the counts.

8. A scene-change-point detection apparatus according to claim 7, wherein information required for detection of a scene change point including the counts are recorded as user data.

9. A scene-change-point detection apparatus according to claim 7 and said scene-change-point detection apparatus is a circuit board having a plurality of integrated circuits interconnected thereon.

10. A scene-change-point detection apparatus according to claim 7, wherein said scene-change-point detection apparatus is a semiconductor integrated circuit chip.

11. A scene-change-point detection apparatus according to claim 7, wherein said detecting means comprises:

means for determining a scene-change-point by comparing the count of the number of blocks in said picture completing said intra-picture compression to a threshold value.

12. A moving-picture editing/displaying system for editing and displaying a moving picture by decoding, editing and displaying a stored, compressed and coded moving picture, said moving picture being coded according to a moving-picture coding process of dividing said moving picture into groups of pictures each having a first picture to undergo intra-picture compression, a plurality of second pictures each to undergo four differential-picture compression, wherein differences between each second picture and a timewise preceding encoded picture are compressed, and a plurality of third pictures each to undergo forward/backward differential-picture compression, wherein differences between each third picture and timewise proceeding encoded picture and a timewise succeeding encoded picture are compressed, dividing each of said pictures into blocks each having a predetermined size, and encoding each of said blocks by one of said intra-picture compression, said forward differential picture compression and forward/backward differential picture compression, said moving-picture editing/displaying system comprising:

means for specifying a picture position in said moving picture;

means for searching said moving picture for said specified picture position in a process of decoding said stored, compressed and coded moving picture;

means for detecting a scene change point preceding said picture position and a scene change point succeeding said picture position,

said detecting means comprises;

means for counting the number of blocks in a picture completing said differential-picture compression, counting the number of blocks in said picture completing said intra-picture compression, and counting the number of blocks in said picture completing no compression, and

means for detecting whether a scene-change-point exists in said picture based on the counts; and

means for displaying pictures starting with a picture at said scene change point preceding said picture position and ending with a picture at said scene change point succeeding said picture position.

13. A moving-picture editing/displaying system according to claim 12, wherein information required for detection of a scene change point including the counts are recorded as user data.

14. A moving-picture editing/displaying system according to claim 12, wherein said detecting means further comprises:

means for determining a scene-change-point by comparing the count of the number of blocks in said picture completing said intra-picture compression to a threshold value.

15. A moving-picture editing/displaying system according to claim 12, wherein said moving-picture editing/displaying system is a video camera.

16. A moving-picture editing/displaying system according to claim 12, wherein said moving-picture editing/displaying system is a video tape recorder.

17. A computer program stored on a storage medium for detecting a scene change point in a moving picture which has been coded according to a moving-picture coding process of dividing said moving picture into groups of pictures each having a first picture to undergo intra-picture compression, a plurality of second pictures each to undergo forward differential-picture compression, wherein differences between each second picture and a timewise preceding encoded picture are compressed and a plurality of third pictures each to undergo forward/backward differential-picture compression wherein differences between each third picture and a timewise preceding encoded picture and a timewise succeeding encoded picture are compressed, dividing each of said pictures into blocks each having a predetermined size, and encoding each of said blocks by one of said intra-picture compression, said forward differential picture compression and said forward/backward differential picture compression, said computer program when executed by a computer causes said computer to perform the steps of:

counting the number of blocks in a picture completing said differential-picture compression, counting the number of blocks in said picture completing said intra-picture compression and counting the number of blocks in said picture completing no compression; and

detecting whether a scene change point exists in said picture based on the counts.

18. A computer program according to claim 17, wherein information required for detection of a scene change point including the counts are recorded as user data.

19. A computer program according to claim 17, wherein said detecting step comprises the step of:

determining a scene-change-point by comparing the count of the number of blocks in said picture completing said intra-picture compression to a threshold value.

20. A computer program stored on a storage medium for editing and displaying a moving picture by decoding, editing and displaying a stored, compressed and coded moving picture, said moving picture being coded according to a moving-picture coding process of dividing said moving picture into groups of pictures each having a first picture to undergo intra-picture compression, a plurality of second pictures each to undergo four differential-picture compression, wherein differences between each second picture and a timewise preceding encoded picture are compressed, and a plurality of third pictures each to undergo forward/backward differential-picture compression, wherein differences between each third picture and timewise proceeding encoded picture and a timewise succeeding encoded picture are compressed, dividing each of said pictures into blocks each having a predetermined size, and encoding each of said blocks by one of said intra-picture compression, said forward differential picture compression and forward/backward differential picture compression, said computer program when executed by a computer causes said computer to perform the steps of:

specifying a picture position in said moving picture;

searching said moving picture for said specified picture position in a process of decoding said stored, compressed and coded moving picture;

detecting a scene change point preceding said picture position and a scene change point succeeding said picture position, said detecting step comprises the steps of;

counting the number of blocks in a picture completing said differential-picture compression, counting the number of blocks in said picture completing said intra-picture compression, and counting the number of blocks in said picture completing no compression, and

detecting whether a scene-change-point exists in said picture based on the counts; and

displaying pictures starting with a picture at said scene change point preceding said picture position and ending with a picture at said scene change point succeeding said picture position.

21. A computer program according to claim 20, wherein information required for detection of a scene change point including the counts are recorded as user data.

22. A computer program according to claim 20, wherein said detecting step comprises the step of:

determining a scene-change-point by comparing the count of the number of blocks in said picture completing said intra-picture compression to a threshold value.

23. A computer program according to claim 20, wherein said storage medium is a memory included in a server connected to a network, and

wherein said server transfers said computer program from said memory included in said server to a memory included in a computer connected to said network.

25. A data structure according to claim 23, wherein said scene-change-point detection apparatus determines a scene-change-point by comparing the count of the number of blocks in said section completing said intra-picture compression to a threshold value.

26. A data structure according to claim 23, wherein information required for detection of a scene-change-point including the counts are recorded as user data.

24. data structure, stored on a machine readable storage medium, said data structure when operated on causes a scene-change-point detection apparatus to detect a scene change point in a moving picture which has been coded according to a moving-picture coding process of dividing said moving picture into groups of pictures each having a first picture to undergo intra-picture compression, a plurality of second pictures each undergo forward differential-picture compression, wherein differences between each second picture and a timewise preceding encoded picture are compressed, and a plurality of third pictures each to undergo forward/backward differential-picture compression, wherein differences between each third picture and a timewise preceding encoded picture and a timewise succeeding encoded picture are compressed, dividing each of said pictures into blocks each having a predetermined size, and encoding each of said blocks by one of said intra-picture compression, said forward differential picture compression and said forward/backward differential picture compression, said data structure comprising:

a first count of the number of blocks in a picture completing said differential-picture compression;

a second count of the number of blocks in said picture completing said intra-picture compression,

a third count of the number of blocks in said picture completing no compression,

wherein said scene-change-point detection apparatus detects whether a scene change point exists in said picture based on the counts.