Television – Bandwidth reduction system – Data rate reduction
Patent
1995-09-20
1998-05-05
Britton, Howard W.
Television
Bandwidth reduction system
Data rate reduction
348419, H04N 732, H04N 730
Patent
active
057482438
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method for encoding motion picture, a method for decoding motion picture, a motion picture recording medium, and a motion picture encoding apparatus, and is applicable to, for example, record a motion picture signal on a recording medium such as an optical disk and a magnetic tape to reproduce to display on a display device and so on, and to transmit from a transmitting side to a receiving side via a transmission path to be received and displayed by the receiving side, such as a motion picture signal for a television conference system, a television telephone system, and a broadcasting equipment.
BACKGROUND ART
In the case, for example, of systems for transmitting a motion picture signal to a remote place, such as a television conference system and a television telephone system, the picture signal is compressed and encoded by utilizing the linear correlation or the correlation between frames of the motion picture signal in order to use the transmission path efficiently. In fact, when the linear correlation is utilized, the amount of information can be compressed, for example, by processing the picture signal in accordance with an orthogonal conversion method such as a discrete cosine transform (DCT). Further, when the correlation between frames is utilized, the motion picture signal can be further compressed and encoded.
FIG. 17 shows examples in which the motion picture signals are compressed and encoded using the correlation between frames. In the figure, the three pictures shown in row A indicate frame images PC1, PC2, and PC3 at times t1, t2, and t3, respectively. The difference between the picture signals of the frame images PC1 and PC2 is calculated so that PC12 is generated, and the difference between frame images PC2 and PC3 is calculated so that PC23 is generated. In row B, different pictures are shown and, for convenience, the difference is represented in black.
Generally, pictures of frames temporally adjacent to each other are not substantially different. Therefore, when the difference between the two pictures is calculated, the obtained difference signal is a small value. When this difference signal is encoded, the amount of encoding of the signal can be compressed. For example, in this figure, only the parts shown in black in row B may be encoded. However, when only the difference signals are transmitted, an original picture cannot be restored in the case where the correlation does not exist between the frames as at the change of a scene and the like.
In order to overcome this, it is assumed that the picture of each frame falls into any one of three types of pictures including I-picture (intra-coding), P-picture (forward prediction), and B-picture (bidirectional prediction), and the picture signals are compressed and encoded. Namely, as shown in FIG. 18, the picture signals of 17 frames including frames F1 to F17 are considered as a group of pictures and as one unit for processing. The picture signal of the head frame F1 (the frame shown in black) is encoded by taking it as I-picture. The picture signal of the second frame F2 (the frame shown in white) is processed as B-picture, and the picture signal of the third frame (the frame shown by oblique lines) is processed as P-picture, respectively. After that, the picture signals of the frame F4 to the seventeenth frame F17 are alternately processed as B-picture or P-picture.
As the picture signal of I-picture, a picture signal for one frame is transmitted. On the other hand, for the picture signal of P-picture, as shown in A of FIG. 18, the difference from the picture signal of I-picture or P-picture which is transmitted earlier than the picture signal of P-picture is transmitted basically. Further, as the picture signal of B-picture, as shown in B of FIG. 18, the difference is obtained from the mean value of preceding frame, succeeding frame, or both frames, and then is encoded.
FIG. 19 shows the principle of a method for encoding a motion picture signal in accordance with the manner stated
REFERENCES:
patent: 4559558 (1985-12-01), Hosoya et al.
patent: 4875095 (1989-10-01), Matsumoto et al.
patent: 4953032 (1990-08-01), Suzaki et al.
patent: 4992889 (1991-02-01), Yamagami et al.
patent: 5016104 (1991-05-01), Lim
patent: 5136377 (1992-08-01), Johnston et al.
patent: 5225906 (1993-07-01), Sin
patent: 5388081 (1995-02-01), Hashimoto et al.
patent: 5428394 (1995-06-01), Yamagami et al.
patent: 5434623 (1995-07-01), Coleman et al.
patent: 5475502 (1995-12-01), Lee et al.
patent: 5487087 (1996-01-01), McCree et al.
patent: 5517327 (1996-05-01), Nakatani et al.
patent: 5519456 (1996-05-01), Inamori
patent: 5524067 (1996-06-01), Miyake et al.
patent: 5542008 (1996-07-01), Sugahara et al.
Britton Howard W.
Frommer William S.
Le Vu
Sony Corporation
LandOfFree
Method for encoding and decoding motion picture as a function of does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for encoding and decoding motion picture as a function of, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for encoding and decoding motion picture as a function of will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-59904