Video coding device and video decoding device with a motion compensated interframe prediction

• US 6,275,532 B1
• Filed: 08/29/1996
• Issued: 08/14/2001
• Est. Priority Date: 08/29/1995
• Status: Expired due to Term

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ema, Nobuyuki, Hibi, Keiichi
• Primary Examiner(s): BRITTON, HOWARD W
• Application Number:
  US08/697,731
• Time in Patent Office: 1,811 Days
• Field of Search: 375/240.17
• US Class Current: 375/240.17
• CPC Class Codes: G06T 9/008 Vector quantisation
• CPC Class Codes: H04N 19/109 among a plurality of temporal predictive coding modes
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/517 by encoding
• CPC Class Codes: H04N 19/52 by predictive encoding
• CPC Class Codes: H04N 19/537 Motion estimation other than block-based
• CPC Class Codes: H04N 19/54 using feature points or meshes
• CPC Class Codes: H04N 19/56 Motion estimation with initialisation of the vector search, e.g. estimating a good candidate to initiate a search

Abstract

In a video-coding and video-decoding device, motion-compensated interframe prediction is achieved by determining motion vectors of respective pixels according to representative motion vectors with weighting, and determining accurate motion vectors between video frames, dividing each frame into areas optimal to an objective figure, size and location and performing effective encoding and decoding of the motion vectors. According to the invention a motion-compensated interframe predicting portion generates a predicted video-frame by varying codable area according to a reference video-frame received from a frame memory portion and an input video frame and obtains side-information. A motion vector searching portion searches a motion vector. An effective-area selecting portion selects a valid or invalid mask depending upon a position of a processable object, divides a processable area of the input video frame into suitable areas, a variable-area predicted-frame generating portion generates a predicted frame by affine transformation and translational displacement. An area-diving pattern deciding portion outputs side-information such as the predicted image, motion vectors and divided areas, a side-information coding portion encodes an additional motion vector as a difference from an average basic-motion vector or predictively encodes a motion vector from a median value of three neighboring motion-vectors. A difference between the input video-frame and the predicted video-frame from the predicting portion is encoded, transferred and stored.

Claims

1. A video coding device comprising frame memory means for storing already encoded video signals, motion vector detecting means for determining a representative motion vector per unit area from a difference between an input video signal and a video signal read from the frame memory means, motion vector interpolating means for determining a motion vector per pixel from the representative motion vector, pixel value predicting means for preparing a predicted video signal from a video signal read from the frame memory means by using the motion vector per pixel, wherein weighting coefficient control means for instructing the vector interpolating means to weight a representative motion vector is provided for determining a weighting coefficient for each representative motion vector determined by the motion vector detecting means and instructing the motion vector interpolating means to weight each representative motion vector.

2. A video-coding device as defined in claim 1, wherein the weighting coefficient control means selects one of previously prepared patterns of weighting coefficients for representative vectors and instructs the motion vector interpolating means.

3. A video-coding device as defined in any one of claims 1 and 2, wherein the weight coefficient control means determines a vector weighting coefficient according to a direction of each representative motion vector.

4. A video-coding device as defined in any one of claims 1 and 2, wherein the weight coefficient control means determines a vector weighting coefficient according to a vector value of each representative motion vector.

5. A video decoding device comprising frame memory means for storing already decoded video signals, motion vector interpolating means for determining a motion vector per pixel from a representative motion vector inputted per unit area, pixel value predicting means for preparing a predicted video signal from a video signal read from the frame memory means by using the motion vector per pixel, wherein weighting coefficient control means for instructing the motion vector interpolating means to weight a representative motion vector is provided for determining a weighting coefficient for each representative motion vector and instructing the motion vector interpolating means to weight each representative motion vector.

6. A video-decoding device as defined in claim 5, wherein the weighting coefficient control means selects one of previously prepared patterns of weighting coefficients for representative vectors and instructs the motion vector interpolating means.

7. A video-decoding device as defined in any one of claims 5 and 6, wherein motion vector converting means is provided for determining a motion vector for a skipped frame from a representative motion vector inputted for a unit area of encoded image frame and an interpolating video signal corresponding to an image frame skipped without being encoded is prepared.

8. A video coding device for encoding predicted error-information determined as a difference between an input video-frame and an predicted video-frame obtained by executing motion-compensated interframe prediction, wherein a motion-compensative interframe predicting portion is provided with a variable-area predicted-frame generating portion for dividing a processable area of the input video-frame into suitable areas according to motion vectors and a reference video-frame and generating a predicted video-frame by affine transformation and a area dividing pattern deciding portion for controlling dividing of a processable area and outputting a predicted video-frame and side-information such as motion vectors and area-dividing information.

11. A video coding device as defined in any one of claims 8 and 9, which encodes predicted error information determined as a difference between an input video-frame and a predicted video-frame obtained by executing motion-compensated interframe prediction, wherein the motion-compensated interframe-predicting portion is provided with an effective-area selecting portion for selecting a valid processing mask or an invalid processing mask depending upon location of an objective area in a video-frame when searching a motion vector.

13. A video coding device as defined in any one of claims 8 and 9, wherein the motion-vector coding portion of the area-dividing pattern deciding portion is provided with a side-information coding portion for encoding an additional motion vector as a difference from a mean of four basic motion-vectors.

15. A video coding device as defined in any one of claims 8 and 9, wherein the motion-vector coding portion of the area-dividing pattern deciding portion is provided with a side-information coding portion for encoding an additional motion vector positioned between two basic motion-vectors as a difference from a mean of the two basic motion-vectors and encoding a center additional motion-vector as a difference from a mean of four basic motion-vectors.

19. A video coding device as defined in any one of claims 8 and 9, wherein the area-dividing pattern deciding portion is provided with a motion-vector coding portion comprising a side-information coding portion for encoding an objective motion-vector value by prediction from values of three motion-vectors which are already encoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector.

20. A video coding device as defined in any one of claims 8 and 9, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing pattern deciding portion for instructing kinds of dividing patterns of all areas to the variable-area predicted-frame generating portion, adopting an area-dividing pattern minimizing a prediction error (error information value), outputting motion-vectors and area-dividing information to side-information coding portion and outputting a predicted video-frame.

21. A video coding device as defined in any one of claims 8 and 9, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing deciding portion which instructs the variable-area predicted-frame generating portion to divide an area into two small areas as an initial setting and/or make prediction by translational displacement, instructs the variable-area predicted-frame generating portion to more finely divide the area again if a predicted error (error information value) of a predicted-frame generated with the initial setting exceeds a preset threshold value, and which deciding portion outputs motion-vectors and area-dividing information to the side-information coding portion when the prediction error (error information value) became smaller than the preset threshold value, and also outputs a predicted video-frame.

22. A video coding device as defined in any one of claims 8 and 9, which is provided with a subtracting portion whereto the input video frame and the predicted video-frame from the motion-compensated interframe-predicting portion are transferred, a video coding portion for encoding an error (differential) video-frame received from the subtracting portion according to an instruction of the coding control portion, a video decoding portion for decoding a coded video frame from the video coding portion, an adder potion for adding a predicted video-frame received from the motion-compensated interframe-predicting portion to a decoded video-frame received from the video decoding portion and a frame memory for storing a reference video-frame inputted from the adder portion and outputting stored information to the motion-compensated interframe-predicting portion.

43. A video coding device as defined in any one of claims 8 and 9, wherein the area-dividing pattern deciding portion is provided with a motion-vector coding portion which is provided with a side-information coding portion for encoding an objective motion-vector value by prediction from values of three motion-vectors which are already encoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector, wherein the motion-vector coding portion determines a mean of the three motion-vectors as a predicted value of the objective motion-vector and encodes a difference between the objective motion-vector and the predicted value.

44. A video coding device as defined in any one of claims 8 and 9, wherein the area-dividing pattern deciding portion is provided with a motion-vector coding portion which is provided with a side-information coding portion for encoding an objective motion-vector value by prediction from values of three motion-vectors which are already encoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector, wherein the motion-vector coding portion determines a median of the three motion-vectors as a predicted value of the objective motion-vector and encodes a difference between the objective motion-vector and the predicted value.

45. A video coding device as defined in claim 11, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing pattern deciding portion for instructing kinds of dividing patterns of all areas to the variable-area predicted-frame generating portion, adopting an area-dividing pattern minimizing a prediction error (error information value), outputting motion-vectors and area-dividing information to side-information coding portion and outputting a predicted video-frame.

46. A video coding device as defined in claim 13, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing pattern deciding portion for instructing kinds of dividing patterns of all areas to the variable-area predicted-frame generating portion, adopting an area-dividing pattern minimizing a prediction error (error information value), outputting motion-vectors and area-dividing information to side-information coding portion and outputting a predicted video-frame.

47. A video coding device as defined in claim 15, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing pattern deciding portion for instructing kinds of dividing patterns of all areas to the variable-area predicted-frame generating portion, adopting an area-dividing pattern minimizing a prediction error (error information value), outputting motion-vectors and area-dividing information to side-information coding portion and outputting a predicted video-frame.

48. A video coding device as defined in claim 19, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing pattern deciding portion for instructing kinds of dividing patterns of all areas to the variable-area predicted-frame generating portion, adopting an area-dividing pattern minimizing a prediction error (error information value), outputting motion-vectors and area-dividing information to side-information coding portion and outputting a predicted video-frame.

49. A video coding device as defined in claim 11, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing deciding portion which instructs the variable-area predicted-frame generating portion to divide an area into two small areas as an initial setting and/or make prediction by translational displacement, instructs the variable-area predicted-frame generating portion to more finely divide the area again if a predicted error (error information value) of a predicted-frame generated with the initial setting exceeds a preset threshold value, and which deciding portion outputs motion-vectors and area-dividing information to the side-information coding portion when the prediction error (error information value) became smaller than the preset threshold value, and also outputs a predicted video-frame.

50. A video coding device as defined in claim 13, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing deciding portion which instructs the variable-area predicted-frame generating portion to divide an area into two small areas as an initial setting and/or make prediction by translational displacement, instructs the variable-area predicted-frame generating portion to more finely divide the area again if a predicted error (error information value) of a predicted-frame generated with the initial setting exceeds a preset threshold value, and which deciding portion outputs motion-vectors and area-dividing information to the side-information coding portion when the prediction error (error information value) became smaller than the preset threshold value, and also outputs a predicted video-frame.

51. A video coding device as defined in claim 15, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing deciding portion which instructs the variable-area predicted-frame generating portion to divide an area into two small areas as an initial setting and/or make prediction by translational displacement, instructs the variable-area predicted-frame generating portion to more finely divide the area again if a predicted error (error information value, of a predicted-frame generated with the initial setting exceeds a preset threshold value, and which deciding portion outputs motion-vectors and area-dividing information to the side-information coding portion when the prediction error (error information value) became smaller than the preset threshold value, and also outputs a predicted video-frame.

52. A video coding device as defined in claim 19, wherein the motion-compensated interframe-predicting portion is provided with an area-dividing deciding portion which instructs the variable-area predicted-frame generating portion to divide an area into two small areas as an initial setting and/or make prediction by translational displacement, instructs the variable-area predicted-frame generating portion to more finely divide the area again if a predicted error (error information value) of a predicted-frame generated with the initial setting exceeds a preset threshold value, and which deciding portion outputs motion-vectors and area-dividing information to the side-information coding portion when the prediction error (error information value) became smaller than the preset threshold value, and also outputs a predicted video-frame.

53. A video coding device as defined in claim 11, which is provided with a subtracting portion whereto the input video frame and the predicted video-frame from the motion-compensated interframe-predicting portion are transferred, a video coding portion for encoding an error (differential) video-frame received from the subtracting portion according to an instruction of the coding control portion, a video decoding portion for decoding a coded video frame from the video coding portion, an adder portion for adding a predicted video-frame received from the motion-compensated interframe-predicting portion to a decoded video-frame received from the video decoding portion and a frame memory for storing a reference video-frame inputted from the adder portion and outputting stored information to the motion-compensated interframe-predicting portion.

54. A video coding device as defined in claim 20, which is provided with a subtracting portion whereto the input video frame and the predicted video-frame from the motion-compensated interframe-predicting portion are transferred, a video coding portion for encoding an error (differential) video-frame received from the subtracting portion according to an instruction of the coding control portion, a video decoding portion for decoding a coded video frame from the video coding portion, an adder portion for adding a predicted video-frame received from the motion-compensated interframe-predicting portion to a decoded video-frame received from the video decoding portion and a frame memory for storing a reference video-frame inputted from the adder portion and outputting stored information to the motion-compensated interframe-predicting portion.

55. A video coding device as defined in claim 21, which is provided with a subtracting portion whereto the input video frame and the predicted video-frame from the motion-compensated interframe-predicting portion are transferred, a video coding portion for encoding an error (differential) video-frame received from the subtracting portion according to an instruction of the coding control portion, a video decoding portion for decoding a coded video frame from the video coding portion, an adder portion for adding a predicted video-frame received from the motion-compensated interframe-predicting portion to a decoded video-frame received from the video decoding portion and a frame memory for storing a reference video-frame inputted from the adder portion and outputting stored information to the motion-compensated interframe-predicting portion.

9. A video coding device for encoding predicted error information determined as a difference between an input video-frame and an predicted video-frame obtained by executing motion-compensated interframe prediction, wherein a motion-compensated interframe-predicting portion is provided with a variable-area predicted-frame generating portion for dividing a processable area of the input video-frame into suitable areas according to motion vectors and a reference video frame and generating a predicted video-frame by affine transformation and a predicted video-frame by translational displacement of processable areas and an area dividing pattern deciding portion for controlling dividing of a processable area and outputting a predicted video-frame and side-information such as motion vectors and area dividing information.

10. A video coding device for encoding predicted error information determined as a difference between an input video-frame and a predicted video-frame obtained by executing motion-compensated interframe prediction, wherein a motion-compensated interframe-predicting portion is provided with an effective-area selecting portion for selecting a valid processing mask or an invalid processing mask depending upon location of an objective area in a video-frame when searching a motion vector.

12. A video coding device for encoding predicted error information determined as a difference between an input video-frame and a predicted video-frame obtained by executing motion-compensated interframe prediction, wherein a motion-vector coding portion is provided with a side-information coding portion for encoding an additional motion vector as a difference from a mean of four basic motion-vectors.

14. A video coding device for encoding predicted error information determined as a difference between an input video-frame and a predicted video-frame obtained by executing motion-compensated interframe prediction, wherein a motion-vector coding portion is provided with a side-information coding portion for encoding an additional motion vector positioned between two basic motion-vectors as a difference from a mean of the two basic motion-vectors and encoding a center additional motion-vector as a difference from a mean of four basic motion-vectors.

16. A video coding device for encoding predicted error information determined as a difference between an input video-frame and a predicted video-frame obtained by motion-compensated interframe prediction, wherein a motion-vector coding portion is provided with a side-information coding portion for encoding an objective motion-vector value by prediction from values of three motion-vectors which are already encoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector.

17. A video coding device as defined in claim 16, wherein the motion-vector coding portion determines a mean of the three motion-vectors as a predicted value of the objective motion-vector and encodes a difference between the objective motion-vector and the predicted value.

18. A video coding device as defined in claim 16, wherein the motion-vector coding portion determines a median of the three motion-vectors as a predicted value of the objective motion-vector and encodes a difference between the objective motion-vector and the predicted value.

23. A video decoding device for reproducing a video-frame from a coded side-information inputted from a video-coding device and a reference video-frame inputted from a frame memory, wherein a motion-compensated interframe-predicting portion for producing and outputting a predicted video-frame with a changed processable area-size is provided with a side-information decoding portion for decoding coded side-information received from the video coding device and obtaining therefrom motion-vectors and area-dividing information and a variable-area predicted video-frame generating portion for generating a predicted video-frame by using motion vectors and area dividing information received from the side-information decoding portion and a reference video-frame received from the frame memory.

25. A video decoding device as defined in claim 23, wherein the side-information decoding portion decodes four basic motion-vectors contained in the side-information before decoding motion-vectors and for decoding additional motion-vectors representing a difference from a mean of the basic vectors.

27. A video decoding device as defined in claim 23, wherein a side-information decoding portion decodes four basic motion-vectors contained in the side-information before decoding motion-vectors and decodes an additional motion-vector positioned between two basic motion-vectors as a difference from an obtained mean of the two basic motion-vectors and decoding a center additional motion-vector as a difference from an obtained mean of four basic motion-vectors.

31. A video decoding device as defined in claim 23, wherein the side-information decoding portion is provided with a motion-vector decoding system for decoding a objective motion-vector value by prediction from values of three motion-vectors which are already decoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector.

32. A video decoding device as defined in any one of claims 23, 25, and 27, wherein it is further provided with a video decoding portion for decoding a coded video-information inputted from a video coding device and outputting the decoded video-information, an adder portion for adding a decoded video-frame inputted from the video decoding portion to a predicted video-frame inputted from the motion-compensated interframe predicting portion and outputting an obtained video-frame as an output video-frame and a frame memory for storing a video-frame from the adder portion and for outputting said stored video-frame as a reference video-frame to the motion-compensated interframe predicting portion.

56. A video decoding device as defined in claim 23, wherein the side-information decoding portion is provided with a motion-vector decoding system for decoding a objective-vector value by prediction from values of three motion-vectors which are already decoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector,

wherein the side-information decoding portion determines a mean of the three motion-vectors as a predicted value of the objective motion-vector and obtains a decoded objective motion-vector value by adding the decoded difference value to the predicted value.

57. A video decoding device as defined in claim 23, wherein the side-information decoding portion is provided with a motion-vector decoding system for decoding a objective-vector value by prediction from values of three motion-vectors which are already decoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector,

wherein the side-information decoding portion determines a median of the three motion vectors as a predicted value of the objective motion-vector and obtains a decoded objective motion-vector value by adding the decoded difference value to the predicted value.

24. A video decoding device for reproducing a video-frame from a coded side-information inputted from a video-coding device and a reference video-frame inputted from a frame memory, wherein a side-information decoding portion is provided for decoding four basic motion-vectors contained in the side-information before decoding motion-vectors and for decoding additional motion-vectors representing a difference from a mean of the basic vectors.

26. A video decoding device for reproducing a video-frame from a coded side-information inputted from a video-coding device and a reference video-frame inputted from a frame memory, wherein a side-information decoding portion is provided for decoding four basic motion-vectors contained in the side-information before decoding motion-vectors and for decoding an additional motion-vector positioned betweentwo basic motion-vectors as a difference from an obtained mean of the two basic motion-vectors and decoding a center additional motion-vector as a difference from an obtained mean of four basic motion-vectors.

28. A video decoding device for reproducing a video-frame from a coded side-information inputted from a video-coding device and a reference video-frame inputted from a frame memory, wherein a side-information decoding portion is provided for decoding a objective motion-vector value by prediction from values of three motion-vectors which are already decoded basic or additional motion-vectors existing at the left-side, the just upper-side and the upper right-side of the object motion vector.

29. A video decoding device as defined in claim 28, wherein the side-information decoding portion determines a mean of the three motion-vectors as a predicted value of the objective motion-vector and obtains a decoded objective motion-vector value by adding the decoded difference value to the predicted value.

30. A video decoding device as defined in claim 28, wherein the side-information decoding portion determines a median of the three motion vectors as a predicted value of the objective motion-vector and obtains a decoded objective motion-vector value by adding the decoded difference value to the predicted value.

33. A video coding device using an adaptive motion-compensated interframe-prediction system, comprising:

a predicting portion for producing a plurality of predictive images of variable-size areas by applying different predicting methods to each of the variable-size areas in the process of the motion-compensated interframe prediction and outputting the produced predictive images;

an area prediction deciding portion for determining an adaptive area size and an adaptive prediction method according to a plurality of the predictive images received from the predicting portion and outputting side-information including area-information, prediction-mode information, motion-vectors and so on;

and a side-information coding portion for encoding the side-information outputted from the area prediction deciding portion.

37. A video coding device using adaptive motion-compensated interframe-prediction system, as defined in any one of claims 33, 34 and 35, wherein it is provided with a predicting portion for diagonally dividing each encodable unit-area into two or four subareas, producing a predictive image for each subarea by applying different prediction methods in the process of the motion-compensated interframe prediction and outputting the produced predicted images.

34. A video coding device using an adaptive motion-compensated interframe-prediction system, comprising:

a predicting portion for producing a plurality of predictive images of respective unit areas or further-divided subareas by applying different predicting methods to each of the unit areas or each of the subareas in the process of the motion-compensated interframe prediction and then outputting the produced predictive images;

an area prediction deciding portion for determining an area-information indicating whether the predicted images received from the predicting portion are unit-area images or subarea images and prediction methods applied to the respective predicted images and outputting side-information including area-information, prediction mode information, motion-vectors and so on; and

a side-information coding portion for encoding the side-information received from the area prediction deciding portion.

35. A video coding device using an adaptive motion-compensated interframe-prediction system, comprising:

a predicting portion for producing a plurality of predictive images of respective variable-size areas by using a block-displacement (overlapped motion-compensative) predicting method, an affine transform predicting method, bilinear transform predicting method and a background predicting method, etc. in the process of the motion-compensated interframe prediction and then outputting the produced predictive images;

an area prediction deciding portion for determining an adaptive area-size and an adaptive prediction method according to a plurality of the predictive images received from the predicting portion and outputting side-information including area-information, prediction mode information and motion-vectors and so on; and

a side-information coding portion for encoding the side-information received from the area prediction deciding portion.

36. A video coding device using an adaptive motion-compensated interframe-prediction system, which is provided with a predicting portion for diagonally dividing each encodable unit-area into two or four subareas, producing a predictive image for each subarea by affine transformation in the process of the motion-compensated interframe prediction and outputting the produced predicted images.

38. A video decoding device using an adaptive motion-compensated interframe-prediction system, comprising:

a side-information decoding potion for decoding coded side-information including area-information, prediction mode information and motion-vectors, and so on and outputting the decoded side-information;

a predicting portion for producing a plurality of predictive images of variable-size areas by applying different predicting methods to each of the variable-size areas in the process of the motion-compensated interframe prediction and outputting the produced predictive images; and

an area-prediction-mode selecting portion for producing an adaptive predictive image from a plurality of the predictive images received from the predicting portion according to the information received from the side-information decoding portion and outputting the produced predictive images.

42. A video decoding device using an adaptive motion-compensated interframe prediction system, as defined in any one of claims 38, 39 and 40, wherein it is provided with a predicting portion for diagonally dividing each decodable unit-area into two or four subareas, producing a predictive image for each subarea by applying different prediction methods in the process of the motion-compensated interframe prediction and then out a predictive image and outputting the produced predicted images.

39. A video decoding device using an adaptive motion-compensated interframe-prediction system, comprising:

a side-information decoding potion for decoding coded side-information including area-information, prediction mode information and motion-vectors, and so on and outputting the decoded side-information;

a predicting portion for producing a plurality of predictive images of respective decodable unit-areas or further-divided subareas by applying different predicting methods to each of the unit areas or each of the subareas in the process of the motion-compensated interframe prediction and then outputting the produced predictive images; and

an area-prediction-mode selecting portion for producing an adaptive predictive image from a plurality of the predictive images received from the predicting portion according to the information received from the side-information decoding portion and then outputting the produced predictive images.

40. A video decoding device using an adaptive motion-compensated interframe-prediction system, comprising:

a side-information decoding potion for decoding coded side-information including area-information, prediction mode information and motion-vectors, and so on and outputting the decoded side-information;

a predicting portion for producing a plurality of predictive images of respective decodable unit-area or further divided subareas by using a block-displacement (overlapped motion-compensative) predicting method, an affine transform predicting method, bilinear transform predicting method and a background predicting method, etc. in the process of the motion-compensated interframe compensated interframe prediction and then outputting the produced predictive images; and

an area-prediction-mode selecting portion for producing an adaptive predictive image from a plurality of the predictive images received from the predicting portion according to the information received from the side-information decoding portion and outputting the produced predicted images.

41. A video decoding device using an adaptive motion-compensated interframe prediction system, which is provided with a predicting portion for diagonally dividing each decodable unit-area into two or four subareas, producing a predictive image for each subarea by affine transformation in the process of the motion-compensated interframe prediction and outputting the produced predicted images.