Image data encoding method and device, image data reconstructing method and device, scene change detecting method and device, scene change recording device, and image data scene change record/regenerating device

• US 5,614,960 A
• Filed: 06/19/1996
• Issued: 03/25/1997
• Est. Priority Date: 09/07/1992
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Noda, Tsugio, Chiba, Hirotaka
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US08/663,866
• Time in Patent Office: 279 Days
• Field of Search: 348/700, 348/415, 348/416
• US Class Current: 348/700
• 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 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• 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
• CPC Class Codes: H04N 7/54 the signals being synchronous H04N21/23602, H04N21/23614, H04N21/2365, H04N21/2368, H04N21/4341, H04N21/4342, H04N21/4347, H04N21/4348 take precedence
• CPC Class Codes: H04N 9/8047 using transform coding

Abstract

An encoding unit encodes the received image data in frame units. A code buffer stores the amount of codes per 1 frame. The detection condition setting unit sets a detection condition (a standard value of a code amount difference) specified according to the detection designation data entered externally. A scene determining unit calculates the difference between the amount of codes in the present frame entered from the code buffer and the amount of codes in the previous frame. If the difference is larger than the detection condition (the standard value of the code amount difference), the scene determining unit issues a COS code indicating a scene-changed frame and sets a selection signal in an active state. A switch adds the COS code to the encoded data in the present frame and externally outputs it when the selection signal indicates an active state.

Claims

1. An image data encoding method for encoding image data comprising:

a detection condition storing step of storing a detection condition set for detecting a scene-changed frame;

an encoding step of encoding image data of an input frame;

a code amount storing step of storing the amount of codes in the data, encoded in said encoding step, of previous and present frames;

a determining step of determining whether or not the present frame is a scene-changed frame according to the amount of codes of the previous and present frames stored in said code amount storing step 3 and to the condition set for detecting a scene-changed frame stored in said detection condition storing step;

and an output step for outputting, as a determination result of said determining step, said encoded data generated in the code amount storing step and a code indicating a scene-changed frame if the present frame is a scene-changed frame, and only the encoded data if the present frame is not a scene-changed frame, wherein

said encoding step, said code amount storing step, said determining step, and said output step are performed on image data in a plurality of frames whose data are to be encoded.

2. The image data reconstructing method of reconstructing image data from encoded data obtained by the image data encoding method according to claim 1, comprising:

an identifying step of identifying a scene-changed frame among the encoded data; and

a reconstructing step of reconstructing only the codes of the scene-changed frames identified by said identifying step.

3. An image data encoding device for encoding image data comprising:

frame encoding means for sequentially encoding image data in an input frame;

frame encoded data storing means for storing encoded data of frames whose data are encoded by said frame encoding step 8;

detection condition storing means for storing the condition set for detecting that a frame encoded by said frame encoding means is a scene-changed frame;

scene-changed frame detecting means for detecting a scene-changed frame according to the difference in the amount of codes between the encoded data in the previous frame stored in said frame code storing means and the data, encoded by said frame encoding means, in the present frame, and to the detection condition stored in said detection condition storing means; and

output means for outputting encoded data stored in said frame code storing means and encoded data indicating a scene-changed frame for a scene-changed frame detected by said scene-changed frame detecting means, and outputting only the encoded data for a normal frame (scene-unchanged frame).

4. The image data encoding device according to claim 3, wherein

said detection condition storing means stores as the detection condition of a scene-changed frame a standard value of the difference in the amount of codes between adjacent frames.

5. The image data encoding device according to claim 3, wherein

said detection condition storing means stores as the detection condition of a scene-changed frame the standard value of the rate of difference in the amount of codes between adjacent frames.

6. The image data reconstructing device according to claim 3 for reconstructing image data from the data encoded by said image data encoding device according to claim 3, comprising:

scene-changed frame detecting means for extracting encoded data of a scene-changed frame from all encoded data;

encoded data reconstructing means for reconstructing image data from the encoded data of a scene-changed frame extracted by said scene-changed frame detecting means;

scene-changed frame image storing means for storing image data of a scene-changed frame reconstructed by said encoded data reconstructing means; and

display instructing means for instructing a method of displaying image data in a scene-changed frame stored by said scene-changed frame image storing means.

7. The image data reconstructing means according to claim 6, wherein

said display instructing means instructs such that scene-changed frames are displayed in sequence.

8. The image data reconstructing device according to claim 6, wherein

said display instructing means instructs such that images of a plurality of scene-changed frames are reduced to be displayed on one screen.

9. An image data reconstructing device for reconstructing image data from moving picture data encoded by an image data encoding device, comprising:

frame encoded data storing means for storing encoded data of frames;

detection condition storing means for storing the condition set for detecting that the present frame is a scene-changed frame;

scene-changed frame detecting means for extracting encoded data of scene-changed frames from the encoded data according to the detection condition stored in said detection condition storing means and to the difference in the amount of codes, between adjacent frames, inputted from said frame encoded data storing means;

encoded data reconstructing means for reconstructing image data from encoded data of scene-changed frames extracted by said scene-changed frame detecting means;

scene-changed frame image storing means for storing image data of the scene-changed frames reconstructed by said encoded data reconstructing means; and

display instructing means for instructing a method of displaying image data in a scene-changed frame stored by said scene-changed frame image storing means.

10. A scene change detecting method comprising:

a detection condition storing step of storing a detection condition set for detecting changes of scenes in moving picture data;

an encoding step of encoding image data in a frame;

a code amount storing step of storing the amount of codes, in a frame, encoded by the encoding step 24;

a scene change determining step of determining a change of scenes according to the amount of codes of the previous and present frames stored in said code amount storing step and to the detection condition stored in said detection condition storing step; and

a change signal outputting step of outputting a scene change detection signal according to the determination result of said scene change determining step.

11. The scene change detecting method according to claim 10, wherein

said encoding step reduces an original image and performs an encoding process on image data having the reduced amount of data.

12. A scene change detecting device comprising:

detection condition storing means for storing the condition set for detecting changes of scenes in moving picture data;

previous frame code amount storing means for storing the amount of codes in image data in the previous frame;

present frame code amount storing means for storing the amount of codes in image data in the present frame;

code difference storing means for obtaining a difference between the amount of codes in the previous frame stored in said previous frame code amount storing means and the amount of codes in the present frame stored in said present frame code amount storing means, and storing the difference; and

scene change detecting means for detecting changes of scenes according to the difference in the amount of codes stored in said code difference storing means and to the detection condition stored in said detection condition storing means, and outputting a scene change detection signal when changes of scenes are detected.

13. A scene change recording device, comprising:

signal converting means for outputting a record instruction signal based on a scene change detection signal externally applied to indicate a scene-changed frame; and

image signal storing means for recording image data according to the recording instruction signal applied from said signal converting means.

14. The scene change recording device according to claim 13, wherein

said signal converting means consecutively outputs the record instruction signals within a predetermined period each time the scene change detection signal is inputted.

15. The scene change recording device according to claim 13, wherein

the record instruction signal said signal converting means consecutively outputs during a predetermined period if the scene change signals are consecutively inputted for a predetermined number of times.

16. An image data encoding method comprising:

a scene change detection condition storing step of storing the condition set for detecting a change of scenes;

an area dividing step of dividing image data in an input frame to a plurality of small areas;

an encoding step of encoding the image data separately for each small area of the input frame obtained in said area dividing step;

a code amount storing step of calculating and storing the amount of codes of encoded data in each small area obtained in said encoding step;

a code amount difference calculating step for obtaining a predetermined difference in the amount of codes between the present frame and the previous frame in each small area according to the amount of codes of the present and previous frames in each small area stored in said code amount storing step;

a determining step for determining whether or not the present frame is a scene-changed frame according to the difference calculated in said code amount difference calculating step in the amount of codes in each small area between the present frame and the previous frame, and to the detection condition stored in said scene change detection condition storing step; and

an outputting step of outputting data, encoded in said encoding step, of image data together with a code indicating that the present frame is a scene-changed frame if the present frame is determined to be a scene-changed frame in said determining step, and outputting only the data, encoded in said encoding step, of the image data if the present frame is determined not to be a scene-changed frame.

17. The image data encoding method according to claim 16, wherein

a detection condition stored in said scene change detection condition storing step refers to a standard value of the sum of absolute values of the differences between the present and previous frames for all small areas;

said code amount difference calculating step obtains the difference in the amount of codes between the present and previous frames for each small area; and

said determining step obtains the sum of absolute values of the differences in the amount of codes between the present and previous frames, and the sum can be compared with the standard value to detect a scene-changed frame.

18. The image data encoding method according to claim 16, wherein

detection information stored in said scene change detection condition storing step refers to the standard value of the average rate of the amount of codes between the present and previous frames for each small area;

said code amount difference calculating step obtains the rate of the amount of codes between the present and previous frames for each small area; and

said determining step can obtain the average change rate of difference in the amount of codes between the present and previous frames for each small area to detect a scene-changed frame by comparing the average rate of difference with the above described standard value.

19. The image data encoding method according to claim 16, wherein

said area dividing step can divide an input frame to two small areas, that is, odd fields and even fields.

20. The image data encoding method according to claim 16, wherein

said area dividing step can divide an input frame to small areas each indicating a color component when the input frame refers to colored image data.

21. The image data encoding method according to claim 16, wherein

said area dividing step can equally divide an input frame to a plurality of blocks as small areas.

22. The image data encoding method according to claim 16, wherein

said encoding step encodes image data in a small areas in parallel.

23. The image data reconstructing method according to claim 16 for reconstructing an original image from data encoded in the image data encoding method stated in claim 16, comprising:

a reconstructing step of reconstructing image data from said encoded data;

an identifying step of identifying said encoded data of scene-changed frames from said encoded data;

a displaying step of displaying only image data of scene-changed frames identified in said identifying step among image data in each frame reconstructed by said reconstructing step.

24. A scene change detecting device comprising:

detection condition setting means for storing the condition set for detecting a scene-changed frame;

small area dividing means for dividing image data in an input frame to a plurality of small areas;

encoding means for individually encoding image data in the plurality of small areas obtained by said small area dividing means;

previous frame small area code amount storing means for calculating and storing the amount of codes of data, encoded by said encoding means, in all small areas in the previous frame;

code amount difference calculating means for calculating the amount of codes of data, encoded by said encoding means, in all small areas in the present frame, and obtaining the difference in the amount of codes between the present and previous frames in each small area according to the obtained amount of codes in each of the small areas in the present frame and to the amount of codes in each of the small areas stored in said previous frame small area code amount storing means; and

scene-changed frame detecting means for detecting a scene-changed frame according to the difference, calculated by said code amount difference calculating means, in the amount of codes between the present frame and the previous frame for all small areas, and to the detection condition stored by said detection condition setting means, and outputting a scene change detection signal indicating a scene-changed frame if a scene-changed frame has been detected.

25. The scene change detecting device according to claim 24, wherein

said detection condition setting means stores as a detection condition a standard value of the sum of the absolute values of the differences in the amount of codes between the present frame and the previous frame for all small areas;

said code amount difference calculating means obtains the difference in the amount of codes between the present frame and the previous frame for each of the small areas; and

said scene-changed frame detecting means obtains the sum of the absolute values of differences in the amount of codes between the present frame and the previous frame for all small areas, and detects a scene-changed frame by comparing the sum with the above described standard value.

26. The scene change detecting device according to claim 24, wherein

said detection condition setting means stores as a detection condition a standard value of the average rate of difference in the amount of codes between the present frame and the previous frame;

said code amount difference calculating means obtains the rate of the difference in the amount of codes between the present frame and the previous frame for each of the small areas; and

said scene-changed frame detecting means obtains the average rate of difference in the amount of codes between the present frame and the previous frame for small areas, and compares the average rate of difference with said standard value.

27. A scene change recording device receiving a scene change detection signal indicating a change between two frames obtained by calculating a code amount difference in encoded corresponding small areas of the two frames, comprising:

signal converting means for outputting a record instruction signal based on the scene change detection signal; and

image signal storing means for recording image data according to the recording instruction signal applied from said signal converting means.

28. The scene change recording device according to claim 27, wherein

said signal converting means consecutively outputs the record instruction signals within a predetermined period each time the scene change detection signal is inputted.

29. The scene change recording device according to claim 27, wherein

said signal converting means consecutively outputs the record instruction signal during a period from a predetermined scene change detection signal to the next scene change detection signal.

30. The scene change recording device according to claim 27, wherein

said signal converting means consecutively outputs the record instruction signal during a predetermined period if the scene change signals are consecutively inputted for a predetermined number of times.

31. A scene change recording/regenerating device, comprising:

mark signal converting means for converting a scene change detection signal externally applied to indicate a scene-changed frame to a mark signal indicating a change of scenes and for outputting the mark signal;

image recording means for, when recording image data, adding the mark signal outputted by said mark signal converting means to corresponding image data;

image regenerating means for regenerating the image data recorded by said image recording means;

image extracting means for extracting only the image data provided with a mark signal from the image data regenerated by said image data regenerating means; and

image display means for displaying image data extracted by said image extracting means.

32. An image data encoding device comprising:

detection condition setting means for storing the condition set for detecting a scene-changed frame;

small area dividing means for dividing image data in an input frame to a plurality of small areas;

encoding means for individually encoding image data in the plurality of small areas obtained by said small area dividing means;

previous frame small area code amount storing means for calculating and storing an amount of codes of data, encoded by said encoding means, in all small areas in the previous frame;

code amount difference calculating means for calculating the amount of codes of data, encoded by said encoding means, in all the small areas in the present frame, and obtaining a difference in the amount of codes between the present and previous frames in each of the small areas according to the amount of codes in each of the small areas in the present frame and to the amount of codes in each of the small areas stored in said previous frame small area code amount storing means;

scene-changed frame detecting means for detecting a scene-changed frame according to the difference, calculated by said code amount difference calculating means, in the amount of codes between the present frame and the previous frame for all of the small areas, and according to the detection condition stored by said detection condition setting means, and for outputting a scene-changed detection signal when the scene-changed frame has been detected;

frame encoding means for encoding image data applied to said scene-changed frame detecting means; and

data outputting means for outputting a code indicating the scene-changed frame together with the image data encoded by said encoding means, when the scene-changed frame is detected by said scene-changed frame detecting means, and for outputting only the data, encoded by said encoding means, of the image data if the scene-changed frame is not detected by said scene-changed frame detecting means.

33. The image data reconstructing device for reconstructing image data from the data encoded by said image data encoding device according to claim 32, comprising:

reconstructing means for reconstructing image data in each frame from said encoded data;

scene-changed frame detecting means for detecting encoded data in a scene-changed frame in said encoded data;

selecting means for selecting and outputting only image data of a scene-changed frame detected by said scene-changed frame detecting means in image data of each frame reconstructed by said reconstructing means;

image data storing means for storing image data of a scene-changed frame outputted by said selecting means;

display instructing means for instructing a method of displaying image data of a scene-changed frame stored in said image data storing means; and

frame display control means for controlling according to the displaying method instructed by said display instructing means the display of image data of a scene-changed frame stored in said image data storing means.

34. An image data encoding device comprising:

detection condition setting means for storing the condition set for detecting a scene-changed frame;

small area dividing means for dividing image data in an input frame to a plurality of small areas;

encoding means for individually encoding image data in the plurality of small areas obtained by said small area dividing means;

previous frame small area code amount storing means for calculating and storing an amount of codes of data, encoded by said encoding means, in all small areas in the previous frame;

code amount difference calculating means for calculating the amount of codes of data, encoded by said encoding means, in all the small areas in the present frame, and obtaining a difference in the amount of codes between the present and previous frames in each of the small areas according to the amount of codes in each of the small areas in the present frame and to the amount of codes in each of the small areas stored in said previous frame small area code amount storing means;

scene-changed frame detecting means for detecting a scene-changed frame according to the difference, calculated by said code amount difference calculating means, in the amount of codes between the present frame and the previous frame for all of the small areas, and according to the detection condition stored by said detection condition setting means, and for outputting a scene-changed detection signal when the scene-changed frame has been detected;

frame encoding means for encoding image data applied to said scene-changed frame detecting means;

scene-changed frame storing means for storing identification information on a frame detected as the scene-changed frame by said scene-changed frame detecting means; and

data outputting means for sequentially outputting image data encoded by said frame encoding means, and for outputting identification information on all scene-changed frames stored by said scene-changed frame storing means after all encoded data have been outputted.

35. A scene change detecting method for detecting a change of scenes in moving picture data, comprising:

a segmentation information storing step of storing segmentation information which indicates all areas to be extracted from image data in input frames;

a detection condition storing step of storing the condition set for detecting a scene-changed frame in which an image indicates the difference from that in the previous frame;

an image segmenting step of segmenting image data in all areas specified by segmentation information from among image data in input frames according to said segmentation information stored in said segmentation information storing step;

an encoding step of encoding image data in said all areas segmented in said image segmenting step;

a code amount storing step of storing the amount of codes of said data, encoded in said encoding step, in all areas segmented in the previous frame;

a code amount difference calculating step of calculating a predetermined difference between the amount of codes in the data encoded by said encoding step in all specified areas in the present frame and the amount of codes in the encoded data, stored in said code amount storing step, in the previous frame; and

a scene change detecting step of determining whether or not there is a change of scenes between the present frame and the previous frame in a specified area according to the difference calculated in said code amount difference calculating step and to the detection condition stored in said detection condition storing step, and outputting a scene change signal if the determination indicates a scene-changed frame.

36. The scene change detecting method according to claim 35, wherein

the detection condition stored in said detection condition storing step refers to a standard value of the sum of the absolute values of the difference in the amount of codes;

said code amount difference calculating step obtains the sum of the differences in the amount of codes between the present frame and the previous frame for all specified areas;

said scene change detecting step determines whether or not there is a change between the specified area of the present frame and that of the previous frame in a specified area by comparing the sum of the absolute values of the differences in the amount of codes calculated in said code amount difference calculating step with said standard value.

37. The scene change detecting method according to claim 35, wherein

said image segmenting step segments image data of the specified area in reduced image data obtained by reducing original image data in a frame by a predetermined reducing method.

38. The scene change detecting method according to claim 35, wherein

the detection condition stored in said detection condition storing step refers to a standard value of an average rate of difference in the amount of codes;

said code amount difference calculating step obtains said average rate of difference in the amount of codes between the present frame and the previous frame for all specified areas;

said scene change detecting step determines whether or not there is a change of scenes between the present frame and the previous frame in the specified area by comparing said average rate of difference in the amount of codes calculated in said code amount difference calculating step with said standard value.

39. The scene change detecting method according to claim 37, further comprising:

data reducing step for reducing image data of input frames by a predetermined method; and

said image segmenting step segments image data of a specified area in the image data, compressed by said data reducing means, in input frames.

40. The scene change recording method according to claim 39, further comprising:

signal converting step for consecutively outputting a record instruction signal during a period from a predetermined scene change detection signal to the next scene change detection signal.

41. A scene change detecting device for detecting a change of scenes in moving picture data, comprising:

segmentation information storing means for storing segmentation information which indicates all areas to be extracted from image data in input frames;

detecting condition storing means for storing a condition set for detecting a scene-changed frame in which an image indicates a difference from a previous frame;

an image segmenting unit for segmenting image data in all areas specified by the segmentation information from among the image data in the input frames according to the segmentation information stored in said segmentation information storing means;

encoding means for encoding the image data in all areas segmented in said image segmenting means to produce encoded data;

code amount storing means for storing an amount of codes of the image data, encoded in said encoding means, in all areas in the previous frame;

code amount difference calculating means for calculating a predetermined difference between the amount of codes in the image data encoded by said encoding means in all specified areas in a present frame and the amount of codes in the encoded data, stored in said code amount storing means, in the previous frame; and

scene change detecting means for determining whether there is a change of scenes between the present frame and the previous frame in one of the specified areas segmented by said image segmenting unit according to the predetermined difference in the amount of codes calculated in said code amount difference calculating means and to the detection condition stored in said detection condition storing means, and for outputting a scene change detection signal if there is a change of scenes.

42. The scene change detecting device according to claim 41, wherein

said detection condition refers to a standard value of the sum of the absolute values of the differences in the amount of codes;

said code amount difference calculating means obtains the sum of the differences in the amount of codes between the present frame and the previous frame for all specified areas; and

said scene change detecting means determines whether or not there is a change of scenes between the present frame and the previous frame in a specified area by comparing the sum of the absolute values of the differences in the amount of codes calculated in said code amount difference calculating means with said standard value.

43. The scene change detecting device according to claim 41, wherein

said detection condition refers to an average rate of difference in the amount of codes;

said code amount difference calculating means obtains the average rate of difference in the amount of codes between the present frame and the previous frame for all specified areas; and

said scene change detecting means determines whether or not there is a change of scenes between the present frame and the previous frame in a specified area by comparing the average rate of difference in the amount of codes calculated in said code amount difference calculating means with said standard value.

44. The scene change detecting device according to claim 41, wherein said image segmenting means masks the image data in the input frames for the areas other than the specified areas, and outputs to said encoding means the image data to be encoded.

45. The scene change recording/regenerating device according to claim 41, comprising:

mark signal converting means for converting a scene change detection signal outputted by said scene change detecting device according to claim 41 to a mark signal indicating a change of scenes and outputting it;

image recording means for, when recording image data, adding a mark signal outputted by said mark signal converting means to a corresponding image data;

image regenerating means for regenerating the image data recorded by said image recording means; and

image extracting means for extracting only the image data provided with a mark signal from the image data regenerated by said image data regenerating means; and

image display means for displaying image data extracted by said image extracting means.

46. The scene change detecting device according to claim 41, wherein

said encoding means encodes image data simultaneously for the specified areas as if they were a single area when there are a plurality of the specified areas.

47. A scene change recording device, comprising:

signal converting means for outputting a record instruction signal based on a scene change detection signal externally applied to indicate a scene-changed frame after determining the scene-changed frame by checking whether there is a change of scenes between a present frame and a previous frame in an area segmented according to a difference in amount of calculated codes and according to a detection condition; and

image signal storing means for recording image data according to the recording instruction signal applied from said signal converting means.

48. The scene change recording device according to claim 47, wherein

said signal converting means consecutively outputs the record instruction signal within a predetermined period each time the scene change detection signal is inputted.

49. The scene change recording device according to claim 47, wherein

said signal converting means consecutively outputs the record instruction signal during a period from a predetermined scene change detection signal to the next scene change detection signal.

50. The scene change recording device according to claim 47, wherein

said signal converting means consecutively outputted during a predetermined period if the scene change signals are consecutively outputs the record instruction signal for a predetermined number of times.

54. The scene change recording device according to claim 50, wherein

said signal converting means consecutively outputs the record instruction signal during a predetermined period if the scene change signals are consecutively inputted for a predetermined number of times.

51. A scene change recording device receiving a scene change detection signal based on a predetermined difference in the amount of codes of corresponding encoded segmented image data for two frames, comprising:

signal converting means for outputting a record instruction signal based on the scene change detection signal; and

image signal storing means for recording the image data according to the recording instruction signal applied from said signal converting means.

52. The scene change recording device according to claim 51, wherein

said signal converting means consecutively outputs the record instruction signal within a predetermined period each time the scene change detection signal is inputted.

53. The scene change recording device according to claim 51, wherein

said signal converting means consecutively outputs the record instruction signal during a period from a predetermined scene change detection signal to the next scene change detection signal.

55. A scene change recording/regenerating device receiving a scene change detection signal indicating a change between two frames obtained by calculating a code amount difference in image data of the two frames, comprising:

mark signal converting means for converting the scene change detection signal to a mark signal indicating a change of scenes and for outputting the mark signal;

image recording means for, when recording image data, adding a mark signal outputted by said mark signal converting means to corresponding image data;

image regenerating means for regenerating the image data recorded by said image recording means;

image extracting means for extracting only the image data provided with the mark signal from the image data regenerated by said image data regenerating means; and

image display means for displaying the image data extracted by said image extracting means.

56. A scene change recording/regenerating device, comprising:

mark signal converting means for converting a scene change detection signal externally applied to indicate a scene-changed frame by checking whether there is a change of scenes between a present frame and a previous frame in an area segmented according to a difference in amount of calculated codes and according to a detection condition, to a mark signal indicating a change of scenes and for outputting the mark signal;

image recording means for, when recording image data, adding the mark signal outputted by said mark signal converting means to corresponding image data;

image regenerating means for regenerating the image data recorded by said image recording means;

image extracting means for extracting only the image data provided with the mark signal from the image data regenerated by said image data regenerating means; and

image display means for displaying the image data extracted by said image extracting means.

57. A scene change recording/regenerating device, comprising:

high-speed image regenerating means for regenerating image data to be regenerated after skipping a few scenes at a predetermined rate;

image display means for displaying image data regenerated by said high-speed image regenerating means;

scene change detecting means for detecting a change of scenes in the image data after being scene-skipped and regenerated by said high-speed image regenerating means; and

signal converting means for converting a detection signal outputted by said scene change detecting means to a regeneration stop signal to be outputted to said high-speed image regenerating means.

58. An encoding device for encoding image data, comprising:

encoding means for encoding image data of an input frame;

code amount storing means for storing a code amount in image data in a previous frame after the image data are encoded by said encoding means;

determining means for determining whether a present frame is a scene changed frame according to predetermined detection conditions and the code amount in the present frame as encoded by said encoding means compared with the code amount in the image data in the previous frame stored in said code amount storing means; and

output means for outputting data in the input frame as being encoded by said encoding means and encoded data of information specifying a scene-changed frame determined by said determining means.

59. An encoding method for encoding image data, comprising the steps of:

encoding image data in an input frame;

determining whether a present frame is a scene-changed frame according to an amount of codes in the present frame, a code amount in the image data encoded prior to the present frame, and predetermined detection conditions; and

outputting data in the input frame encoded in said encoding step and encoded data of information specifying a scene-changed frame determined in said determining step.