JP2004120499A - Device for encoding and decoding moving image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moving image encoding and decoding device capable of efficiently obtaining excellent image quality even in the moving image with high resolution which has the larger number of pixels than that of an HDTV image. <P>SOLUTION: A screen division part 12 obtains HDTV images 13a, 13b, 13c and 13d for masking, sampling and compressing an original image supplied from an image inputting part 15 having the larger number of (QHDTV) pixels than that of the HDTV image into the required number of HDTV images with the same number as the number of HDTV images necessary for neighborhood pixels of the original image. Then, the influence of a boundary line in the screen caused by screen division is eliminated by performing encoding and decoding in MPEG encoders 14 and MPEG decoders 24 to be able to efficiently obtain excellent image quality even in the moving image with high resolution which has the larger number of pixels than that of the HDTV image. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a moving picture encoding and decoding apparatus, and more particularly to a moving picture encoding and decoding apparatus that divides a captured image and performs MPEG processing to obtain a high-resolution moving image.
[0002]
[Prior art]
In an image pickup apparatus using an image pickup device having a larger number of pixels than a conventional HDTV image, it is difficult to perform various kinds of signal processing without changing a high-frequency analog signal obtained from the image pickup device. A high driving frequency was required to calculate a parallel digital signal obtained by A / D conversion of Furthermore, an apparatus that handles a larger number of pixels than an HDTV image has not been standardized, and it has been necessary to manufacture a dedicated LSI or the like.
[0003]
Therefore, when handling a larger number of pixels than a conventional HDTV image, the image sensor, A / D conversion, and various image processing circuits are driven at a low frequency by dividing the screen into several sets of HDTV images, and are standardized. The function is to use a frequency for an HDTV image and to use a device for the HDTV so as to efficiently obtain a good image quality even at a high resolution.
Also, for image transmission, a plurality of transmission lines of the SDI standard (SDI: serial digital interface) are used in accordance with the number of pixels (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-2002-135662 (page 3-7, FIG. 2)
[0005]
To transmit a moving image of QHDTV (3840 × 2160 pixels) having a number of pixels larger than that of an HDTV image, for example, four times the information amount of HDTV, four HD-SDI systems are required, and the information amount is 1.485 Gbps × 4, which requires a high-speed and large-capacity recording / reproducing device or transmission device for recording or transmitting.
Usually, a compression technique is used to efficiently reduce the amount of such information, and MPEG coding of the most general moving picture compression method is used. However, since the maximum image size specified by MPEG is HDTV, in order to encode a moving image larger than that, it is necessary to change to several sets of HDTV sizes and to encode using a plurality of MPEG encoders. Become. In the case of QHDTV, four units are required. By using compression in this way, it is possible to handle even a recording / reproducing apparatus having a small capacity and a low speed, or a transmission path with a narrow band or a low bit rate.
[0006]
[Problems to be solved by the invention]
By the way, according to the conventional method, the image data input to the MPEG encoder device can be encoded by dividing it into a cross-shaped or a vertically or horizontally divided strip shape.
However, in the conventional cross-shape or vertical or horizontal strip-type division method, there is a connection portion of images in the screen, and encoding is performed due to problems on the decoder side such as transmission errors and decoding errors. There is a problem that the joints between the images that have been obtained can be understood.
[0007]
In addition, since a general MPEG encoder capable of encoding HDTV is intended to be viewed on a display device of HDTV size, bits are mainly allocated to a central portion and bits are not allocated to upper, lower, left and right video areas. In some devices, the compression efficiency is increased, and even if there is no error or the like, the joint portion of the divided image corresponds to a portion to which no bit is assigned, so that the joint becomes conspicuous.
[0008]
The present invention has been made in view of the above points, and a plurality of sets of HDTV, such as an image supplied from an imaging device using an image sensor having a larger number of pixels than an HDTV image, an image supplied from a plurality of HDTV cameras, and the like. When the original image is divided into the required number of HDTV images after compressing and transmitting the moving image, or after restoring the original image via a recording / reproducing device and outputting, it is necessary for neighboring pixels of the original image. After obtaining an HDTV image for masking, sampling and compressing by the same number as the number of frames, MPEG coding is performed to eliminate the influence of the boundary line in the screen caused by the screen division. Provided is a moving image encoding and decoding apparatus capable of efficiently obtaining a high image quality.
[0009]
[Means for Solving the Problems]
The present invention comprises the following means for solving the above-mentioned problems.
That is,
Moving image encoding and decoding in which an original image having a larger number of pixels than HDTV is divided into a plurality of HDTV images on a screen, and the divided HDTV images are MPEG-encoded and decoded in HDTV image units to obtain an original image. Device,
The original image having a larger number of pixels than the HDTV image is masked by the same number of pixels as the number of screens to be screen-divided, sampled, screen-divided, and the original image is converted to an HDTV image for encoding. Screen dividing means for dividing,
MPEG encoding means for MPEG encoding the plurality of HDTV images obtained by the screen dividing means;
MPEG decoding means for decoding the plurality of encoded MPEG encoded signals into an HDTV image;
A moving image encoding / decoding device, comprising: a screen re-synthesizing unit that performs sampling reverse to the sampling of the plurality of decoded HDTV images and re-synthesizes the original HD image as one image. .
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the moving picture encoding and decoding apparatus according to the present invention will be described with reference to preferred embodiments.
FIG. 1 is a schematic block diagram of a moving picture coding and decoding apparatus applied to the present embodiment, and a case where an input picture is a QHDTV (3840 × 2160 pixels) will be described. In the figure, reference numeral 15 denotes a QHDTV image input unit using a conventional technique, and a high-resolution camera using a QHDTV image sensor or four HDTV cameras may be used.
As described above, the QHDTV image input unit 15 divides the QHDTV image shown in FIG. 2 (QHDTV M) into a cross-shape, and (HDTV A), (HDTV B), (HDTV C), (HDTV D) As shown in FIG. As shown by the coordinates, the upper left of the QHDTV image is A, the upper right is B, the lower left is C, and the lower right is D. Each image shows only a part for explanation.
The HDTV image divided into four crosses in this manner is converted into four systems of HD-SDI and supplied to the video encoding device 10.
[0011]
The video encoding device 10 will be described in more detail. The four HD-SDIs supplied from the QHDTV image input unit 15 are converted into four sets of HDTV images by the screen synthesizing unit 11, and then temporarily restored to the original QHDTV image. The operation of the restoration will be described using the left part of FIG. The HD-SDI HDTV conversion unit 104 writes the image converted from the HD-SDI into the HDTV image into the HDTV A memory 103a, the HDTV B memory 103b, the HDTV C memory 103c, and the HDTVD memory 103d. In synchronization with the synchronization of the QHDTV image at the time of reading each HDTV memory, the upper half is alternately read from the HDTV A memory 103a and the HDTVB memory 103b, and the lower half is alternately read from the HDTV C memory 103c and the HDTV D memory 103d to read the original QHDTV image. Is written in the QHDTV memory 101. These memories are controlled by a memory control unit (not shown).
[0012]
Next, sampling by the 2 × 2 pixel block in the screen division unit 12 will be described with reference to FIG. FIG. 7 (QHDTV S) shows a QHDTV image which is an original image restored by the screen synthesizing unit 11. Since the number of pixels of the QHDTV image is four times that of the HDTV image, it is shown in (QHDTV S). Such a mask composed of 2 × 2 4 pixel blocks is applied. Then, (HDTV A ') is applied to the pixels in (1), (HDTVB') is applied to the pixels in (2), and (HDTV C ') is applied to the pixels in (3) so that the masked pixels are not adjacent to each other. , {Circle around (4)} are sampled so as to obtain (HDTVD ′), thereby obtaining an HDTV4 image. Each image shows only a part for explanation.
[0013]
The sampling process will be described in more detail with reference to the right part of FIG. When data is read from the QHDTV memory 101 in which data is stored in the state shown in FIG. 3 (QHDTV S), the first line is written into the HDTV A 'memory 102a and the HDTV B' memory 102b, and the second line is written into the HDTV C 'memory. 102c, writing to the HDTV D 'memory 102d. The same operation is repeatedly and alternately written from the third line. In this way, by controlling each memory by a memory control unit (not shown), an HDTV4 image of (HDTV A ′), (HDTV B ′), (HDTV C ′), (HDTV D ′) is obtained. I have.
[0014]
The reconstructed HDTV images are shown as 13a, 13b, 13c and 13d on the block diagram of FIG. These reconstructed HDTV images are input to four HDTV MPEG encoders 14, respectively, and MPEG encoding is performed. The encoded data is supplied to the recording device and the decoding device by the MPEG-TS transmission (transport stream) specified by DVB-ASI (Digital Video Broadcasting-Asynchronous Serial Interface) as in the related art.
[0015]
In the block diagram of FIG. 1, an example in which the screen synthesizing unit 11 restores a QHDTV image for simplicity of description is shown. However, the present invention uses an existing apparatus by setting the image processing frequency to the HDTV image frequency. As shown in FIG. 4B, four sets of HDTV images divided into squares in the screen dividing unit 12 through the SW 110 (HDTV A ′), (HDTV B ′), (HDTV C ′) And (HDTV D ′) may be configured to obtain an HDTV4 image and then supply the HDTV4 image to the HDTV MPEG encoder 14.
In this way, by applying a mask composed of 4 pixel blocks of 2 × 2 and sampling and dividing, it is possible to disperse the joints of the screen, and to combine a plurality of MPEG encoders in which bits are assigned to the center part of the screen In such a case, it is also possible to configure so that bits are assigned to the central part of the QHDTV image as the original image.
[0016]
Next, the video decoding device 20 will be described. The data compressed by the moving picture coding apparatus 10 is input to the four decoders 24 by the four TS transmissions and decompressed and decoded, thereby obtaining divided screens 23a, 23b, 23c and 23d. The decompressed data is the divided HDTV4 image shown by (HDTV A '), (HDTV B'), (HDTV C '), and (HDTV D') shown in FIG. The split screen input in such a state is processed by the screen re-synthesizing unit 22 into the state of one QHDTV image which is the original image by the procedure reverse to the pixel division described in the encoding, that is, the procedure reverse to that of FIG. To re-synthesize the screen.
[0017]
After that, the original image display screen dividing unit 21 converts the original image into the cross-shaped HDTV image shown in FIG. It is divided, transmitted as HD-SDI 4 systems, and supplied to the QHDTV external display unit 25. Since the input as the image display unit 25 is HD-SDI as in the past, the image display unit 25 does not need to be changed.
As described above, it is also possible to obtain the four HD-SDI signals to be supplied to the image display unit 25 directly from the decompressed HDTV4 image without forming the QHDTV image which is the original image once. Of course.
[0018]
Next, FIG. 5 shows a schematic block diagram of a configuration in which a digital VTR is provided between an encoding unit and a decoding unit in another embodiment. As shown in FIG. 1, digital VTRs 30a, 30b, 30c, and 30d each having an MPEG-TS interface between a moving picture encoding apparatus 10 and a moving picture decoding apparatus 20 are respectively associated with HDTV pictures encoded by MPEG and synchronized. Operation is performed. In this way, not only a real-time high-resolution image transmission system, but also a configuration capable of recording and reproducing a higher-resolution moving image than HDTV on a VTR having existing MPEG-TS transmission as an input / output can be provided.
[0019]
6 and 7 show another embodiment. FIG. 6 is a schematic block diagram of a configuration in which an image input unit is incorporated in an encoding unit, and FIG. 7 is a schematic block diagram of a configuration in which an image display unit is incorporated in a decoding unit. Is shown.
In the moving picture coding apparatus 40 having a configuration in which the image input unit is incorporated in the coding unit shown in FIG. 6, the image obtained by the QHDTV imaging unit 41 is directly supplied to the screen division unit 42, Since a part for converting the input part into HD-SDI and transmitting it and a part for synthesizing the QHDTV image for sampling once can be omitted, the image can be more efficiently encoded. The decoding unit has the same configuration as that of the above-described embodiment.
[0020]
In the moving picture decoding apparatus 50 having a configuration in which the image display section is incorporated in the decoding section shown in FIG. 7, the divided HDTV image decoded by the MPEG decoder 24 is restored by the screen re-synthesizing section 52 to the pixels of the original image. By directly supplying the decoded image to the QHDTV display unit 51, it is possible to omit the original screen display screen division unit for transmitting the decoded image to the external display unit and the unit for converting the decoded image into HD-SDI and transmitting it. Therefore, decoding of the image can be performed more efficiently. The encoding unit has the same configuration as that of the above-described embodiment.
[0021]
In addition, a moving image coding apparatus having a configuration in which an image input unit is incorporated in the encoding unit shown in FIG. 6 in a coding part, and a moving image having a configuration in which an image display unit is incorporated in the decoding unit shown in FIG. A moving picture encoding and decoding apparatus using an image decoding apparatus may of course be used.
[0022]
In the above-described embodiment, the description has been given along the processing of the image having the number of QHDTV pixels. However, if the input image has a larger number of pixels than the HDTV and is an image to be divided into several sets of HDTV images and processed, It can also be used for images with such a number of pixels. In this case, a mask composed of the same number of pixel blocks as the number of screens to be divided may be applied to obtain a plurality of sets of HDTV images for sampling and processing pixels that are not adjacent to each other.
[0023]
【The invention's effect】
As described above, according to the moving picture encoding and decoding apparatus of the present invention, when an image having the number of pixels equal to or larger than the HDTV image is divided into the required number of HDTV images from the original image, After obtaining an HDTV image to be sampled and compressed by masking with the same number as the number of HDTV images required for the compression, MPEG encoding and decoding are performed to eliminate the influence of the boundary line in the screen caused by the screen division. Thus, it is possible to realize a moving picture coding and decoding apparatus capable of efficiently obtaining good picture quality even with a high-resolution moving picture having a larger number of pixels than an HDTV picture.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a moving picture encoding and decoding apparatus applied to an embodiment of the present invention.
FIG. 2 is an example of a QHDTV image applied to an embodiment of the present invention.
FIG. 3 is a diagram illustrating an example of a mask formed of pixel blocks used in a moving picture coding and decoding apparatus applied to an embodiment of the present invention.
FIG. 4 is an example of a schematic block diagram for sampling a plurality of sets of HDTV images for encoding an input image.
FIG. 5 is a schematic block diagram showing a moving picture encoding and decoding apparatus applied to another embodiment of the present invention, wherein a recording and reproducing apparatus is interposed between the moving picture encoding apparatus and the decoding apparatus. .
FIG. 6 is a schematic block diagram of a moving picture encoding and decoding apparatus applied to another embodiment of the present invention.
FIG. 7 is a schematic block diagram of a moving picture coding and decoding apparatus applied to another embodiment of the present invention.
[Explanation of symbols]
10, 40 ... moving picture coding apparatus 20, 50 ... moving picture decoding apparatus 11 ... screen synthesis unit 12, 42 ... screen division unit 14 ... MPEG encoder 15 ... image input unit 22, 52 ... image synthesis unit 24 ... MPEG decoder 25 image display units 30a, 30b, 30c, 30d digital VTR
41 QHDTV imaging unit 51 QHDTV display unit 101 QHDTV memories 102a, 102b, 102c, 102d, 103a, 103b, 103c, 10d HDTV memory 110 SW
104 HD-SDI HDTV conversion unit

Claims (1)

Moving image encoding and decoding in which an original image having a larger number of pixels than the HDTV is divided into a plurality of HDTV images on a screen, and the divided HDTV images are MPEG-encoded and decoded in HDTV image units to obtain an original image. Device,
The original image having a larger number of pixels than the HDTV image is masked by the same number of pixels as the number of screens to be screen-divided, sampled, screen-divided, and the original image is converted into an HDTV image for encoding. Screen dividing means for dividing,
MPEG encoding means for MPEG encoding the plurality of HDTV images obtained by the screen dividing means;
MPEG decoding means for decoding the plurality of encoded MPEG encoded signals into an HDTV image;
A moving image encoding / decoding device, comprising: a screen re-synthesizing unit that performs sampling reverse to the sampling of the plurality of decoded HDTV images and re-synthesizes the original image as one image. .

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