JP2921720B2 - Video signal encoding device by encoding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal by encoding.
The present invention relates to an encoding device .

[0002]

2. Description of the Related Art A conventional video signal encoding and decoding apparatus is shown in FIG. In the figure, (A) shows the configuration of an encoding circuit provided on the transmission side, where 500 is a memory, 501
Is a block encoding unit. (B) shows the configuration of a decoding circuit provided on the receiving side, where 502 is a block decoding unit and 503 is a memory.

Next, the operation will be described. First, on the transmission side, a video signal is input to the memory 500 in a line scanning format, and as shown in FIG. 6A, an 8 × 8 pixel block consisting of 8 columns in the horizontal direction and 8 columns in the vertical direction is used as a unit. Scanning and reading are performed in numerical order. Block encoding section 501
Performs a discrete cosine transform (hereinafter referred to as DCT) on a pixel block, and outputs an 8 × 8 DCT coefficient block. Thereafter, transmission is performed.

On the receiving side, the DCT coefficient block input to the block decoding unit 502 is subjected to an inverse discrete cosine transform (hereinafter, referred to as IDCT) to become a pixel block. Further, the pixel blocks are recorded in the memory 503, read out in a line scanning format, and then a video signal is reproduced. By the way, at this time, the pixel block corresponds to FIG.
As shown in (1), an image of one screen (field) generated one after another is obtained by dividing it vertically and horizontally, and the division pattern is fixed.

[0005] Since the upper, lower, left and right sides of each divided pixel block are coded and decoded for each pixel block, the image information becomes discontinuous, and the quality of the reproduced image inevitably deteriorates. This does not depend on the encoding or decoding method or the image division.

[0006]

As described above,
In a video signal transmission apparatus using the conventional block transform coding, discontinuity (hereinafter referred to as block distortion) occurs at a boundary portion of each reproduced pixel block, and the division pattern of the image remains fixed. Block distortion is localized, which is a major cause of deterioration in visual characteristics.

[0007] Such deterioration cannot be ignored in a video signal transmission device or the like by coding for video broadcasting, which is characterized by high resolution and high quality images, such as high vision. The present invention has been made for the purpose of solving such a problem by temporally changing a division pattern into pixel blocks, that is, a boundary position.

[0008]

In order to achieve the above object, the present invention divides an image of one screen into pixel blocks.
Video signal encoding apparatus for encoding each of the above pixel blocks
And random number generating means for generating one random number for each image
And a predetermined shape formed so that the division boundaries do not coincide with each other
For each image from among the number of divided patterns, the generated
Division that selects one division pattern corresponding to one random number
Pattern selecting means, and
Divides the image of one screen to generate multiple pixel blocks
Image dividing means, and an image generated by the screen dividing means.
And a block coding unit for coding each of the pixel blocks .

[0009]

Here, for a pixel block having a transmission information lacking portion that occurs at the upper and lower ends and the left and right ends of the screen, extrapolation information from image information adjacent to the lacking portion or the latest received information of the portion is used. be composed image information as has information lack portion image correcting means constituting the pixel block using the information reproduction of the transmission information lacking part
Good.

[0011]

With the above arrangement, in the present invention, one screen is displayed.
After dividing an image into pixel blocks,
In a video signal encoding device for encoding, one for each image
And generate them so that the division boundaries do not match each other.
From the predetermined number of divided patterns formed,
One divided pattern corresponding to one generated random number
Select one screen according to the selected division pattern
Image is divided into multiple pixel blocks,
Is encoded for each pixel block.

[0012]

In addition, for a pixel block having transmission information lacking portions that occur at the upper and lower ends and left and right ends of the screen, the transmission information lacking portion image correcting means extrapolates from image information adjacent to the transmission information lacking portion. The pixel block is configured by using the information or the latest received image information of the part for forming the information of the missing part.

[0014]

【Example】

First Embodiment Hereinafter, a description will be given based on one embodiment according to the present invention .
FIG. 1 is a configuration diagram of an embodiment of a video signal transmission device using encoding according to the present invention. In the figure, (A) is an encoding circuit provided on the transmission side, and 100 is a memory, 10
1 is a division determination unit, 102 is a division pattern selection unit, 103
Is a block encoding unit. (B) is a decoding circuit provided on the receiving side, and 104 is a block decoding unit, 10
Reference numeral 5 denotes a memory having a reading function and an image reproducing function.

Next, the procedure of encoding and decoding under the above configuration will be described. First, encoding on the transmission side will be described. A video signal of a screen generated one after another for each time is input to the memory 100 in a line scanning format,
The data is read out in units of 8 × 8 pixel blocks composed of 8 columns in the vertical direction. This pixel block is obtained by dividing a one-field image vertically and horizontally, and has first and second division patterns as shown in FIG. The first and second division patterns are formed such that pixel block boundaries do not coincide with each other. In addition, when the input video signal to be encoded is divided into pixel blocks, the division determination unit 101 detects this for each field, and instructs and determines to alternately select the first and second division patterns as the division pattern. Make According to the determination result, the division pattern selection unit 102
For 0, an instruction on the area to be read and the order is given. As a result of this instruction, the first or second pattern division is performed alternately when reading the screen, and each of the read pixel blocks is further divided by the block coding unit 103.
, And is output as an 8 × 8 DCT coefficient block and transmitted.

Next, decoding on the receiving side will be described.
8 × 8 received and input to block decoding section 104
The DCT coefficient block is subjected to IDCT and converted into an 8 × 8 pixel block. Thereafter, the pixel block is once recorded in the memory 105 and then reconstructed into an image signal of one field. As described above, in this embodiment, two types of divided patterns of pixel blocks having different boundary positions are prepared as divided patterns of an image of one field, and the divided patterns are changed for each field, that is, for each screen of each image that changes with time. By alternately using the two types of division patterns prepared in the above, it is possible to visually reduce deterioration in image quality due to occurrence of block distortion in image encoding and decoding using DCT.

In the above embodiment, the structures and principles of the memories on the transmission side and the reception side, the division determination unit, the division pattern selection unit, the block encoding unit, and the block decoding unit, recognition of one-field images, DCT And the method and principle of IDCT, and a method of forming and reproducing image information that is divided and coded and transmitted after being divided into pixel blocks, more specifically, for example, image information to be transmitted is formed into cells, transmitted and received, Techniques for playback are described in "Electronic Communication Handbook" published by Ohmsha, edited by the Institute of Electronics and Communication Engineers, "Digital PBX Picture Book in ISDN Era" published by Ohmsha et al., Kashimura, et al. Encyclopedia "
Since it is a well-known technology in terms of both hardware and software described in a large number of printed materials, a description thereof is omitted. This also means that random numbers are generated in a second embodiment to be described later, and the adjacent image information of information lacking portions in pixel blocks at the upper and lower and right and left ends of the screen on the receiving side in the fourth embodiment. The same applies to the formation of image information of the relevant section by using the estimated information and the like.

Second Embodiment Next, another embodiment according to the present invention will be described. FIG. 3 is a configuration diagram of an embodiment of a video signal transmission device using encoding according to the present invention. In this figure, (A) is an encoding circuit provided on the transmission side, and the memory 100 and the block encoding unit 103 are the same as those in the previous embodiment, that is, FIG.
Same as (A). (B) is a decoding circuit provided on the receiving side, 104 is a block decoding unit, 105 is a memory, and the configuration and operation conform to the first embodiment. next,
A part according to the invention shown in this embodiment will be described. In the present embodiment, a random number generation unit 301 and a random number corresponding division pattern selection unit 302 for selecting a division pattern corresponding to a random number are provided in place of the division determination unit 101 and the division pattern selection unit 102 in the previous embodiment. The random number generation unit 301 generates one random number (0 to 15) for each field, and the random number corresponding division pattern selection unit 302 separately sets one-to-one correspondence with the types of random numbers, ie, 16 types of divided patterns prepared. The division pattern corresponding to the random number generated from is extracted. At this time, the 16 types of division patterns are formed such that the division boundaries do not coincide with each other as shown in FIG. Based on the above, according to the generated random number and, consequently, the divided pattern corresponding to the generated random number,
Is read out from the block coding unit 10
In step 3, DCT is performed, output as a DCT coefficient block, and transmitted.

On the other hand, on the receiving side, decoding of the received signal coded for each pixel block and subsequent reproduction of an image are performed in the same procedure as in the previous embodiment. As described above, according to the present embodiment, the division pattern is selected by the generated random numbers, so that the locations where the block distortion occurs are dispersed in time and place, and the visual image quality of the screen is degraded. Be insignificant.

(Third Embodiment) Another embodiment of the video signal transmitting apparatus by encoding according to the present invention will be described. This embodiment has a cyclic division pattern selection unit (not shown) for circulating and selecting a natural number from 0 to 9 in place of the random number generation unit 301 in the second embodiment, and corresponding to the selected natural number. Then, a division pattern selection unit (not shown) adopts a corresponding one of ten types of division patterns prepared in advance. Others are in Figure 3
Has the same configuration as the second embodiment shown in FIG.

For this reason, the distortion at the boundary of the pixel block is much smaller than that of the first embodiment because of the large number of divided patterns, and the means for generating random numbers is less than that of the second embodiment. Due to the necessity, the structure, programming, etc. are much easier. Fourth Embodiment A video signal transmission device based on encoding according to the present invention will be described based on another embodiment.

In the first to third embodiments described above, information is lacking in forming a pixel block in a pixel block that occurs in the upper, lower, left and right sides of the screen as it is. This part is conceptually shown at 22 in FIG. 2 and at 44 in FIG. The occurrence of such a portion impairs the quality of the image in the image reproduced and subjected to block coding and decoding, even at the edge of the screen, and is shown in the first to third embodiments. It may reduce the effect of the invention. For this reason, in this embodiment, the receiving side has a transmission information lacking portion image correcting means. Then, the transmission information lacking portion image correcting means, for the portion where the transmission information of the image is insufficient in configuring the pixel block, for each of the color tone, saturation, and brightness of the adjacent pixel block,
The whole image is reproduced after adopting the extrapolated value signal as information of the information lacking portion of the pixel block.

In this case, the image information of the portion corresponding to the transmission information lacking portion of the screen received immediately before may be used for reproduction. At this time, storage means is required,
Extrapolation processing of saturation and lightness becomes unnecessary. As described above, the present invention has been described based on the embodiments. However, it goes without saying that the present invention is not limited to the above embodiments. That is, the following is also covered by the present invention.

(1) At least a part of the constituent elements according to the present invention is added to a video signal transmission device by encoding according to the conventional technology not as a new hardware but as a software. (2) The configuration of the pixel block is not 8 columns × 8 columns, and the horizontal direction and the vertical direction are different from each other, for example, 6 columns × 8 columns according to the imaging device or the video device on the transmission side or the reception side. For encoding and decoding, other transforms such as Hadamard transform and KL transform are used instead of DCT.

(3) As a random number generating means, a random number of about 1000 digits is stored in advance, and the numerical value of each digit of the stored random number is adopted as a sequentially generated random number.

[0026]

As described above, according to the present invention, one screen
Image is divided into pixel blocks, and
A video signal encoding apparatus for encoding an image,
Means for generating two random numbers and the dividing boundary
A predetermined number of divided patterns formed so as not to match
Then, for each image, it corresponds to the one generated random number.
Division pattern selection means for selecting one division pattern;
According to the selected division pattern, an image of one screen is
Image dividing means for dividing to generate a plurality of pixel blocks
And for each pixel block generated by the screen dividing means.
And block encoding means for encoding
A video signal transmission by encoding that has a small perceived degradation in image quality by visually dispersing the location of occurrence of block distortion at random in terms of location and time and preventing block distortion from being localized. The device can be realized.

Also, in the divided pixel block,
The pixel block generated at the top and bottom edges and the left and right edges of the screen
About the information lacking part from the image information adjacent to the part
The extrapolation information or the latest received image information of the
This pixel block is used for forming image information in the transmission information lacking part.
Transmission information lacking part image correction means
Runode, to form the entire screen on which the information of the transmission information lacking portion in a pixel block that occurs in the vertical and left and right ends of the screen supplemented by external挿等further effect of the invention is increased more.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention. (A) shows the configuration of the encoding circuit, and (B) shows the configuration of the decoding circuit.

FIG. 2 shows a division pattern of a field image in the embodiment.

FIG. 3 is a configuration diagram of another embodiment of the present invention. (A) shows the configuration of the encoding circuit, and (B) shows the configuration of the decoding circuit.

FIG. 4 shows a division pattern of a field image in the embodiment.

FIG. 5 is a configuration diagram of a video signal transmission device using encoding according to the related art. (A) shows the configuration of the encoding circuit, and (B) shows the configuration of the decoding circuit.

FIG. 6 shows a pixel block configuration by division of a field image according to the related art. (A) shows the scanning order of the pixel blocks, and (B) shows the configuration of the pixel blocks by dividing the field image.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 memory 101 division determination section 102 division pattern selection section 103 block encoding section 104 block decoding section 105 memory 301 random number generation section 302 random number corresponding division pattern selection section 500 memory 501 block encoding section 502 block decoding section 503 memory

Claims (2)

(57) [Claims] 1. A video signal encoding apparatus that divides an image of one screen into pixel blocks, and encodes each of the pixel blocks.
A is a random number generation means for generating one random number for each image, each image from among the predetermined number of divided patterns formed to divide the boundary does not coincide with each other, one of said generated
Dividing pattern of selecting one division pattern corresponding to the random number
Image selecting means, and an image of one screen according to the selected division pattern.
A video signal by encoding, comprising: an image dividing unit that divides the image to generate a plurality of pixel blocks; and a block encoding unit that encodes each of the pixel blocks generated by the screen dividing unit. Encoding device. 2. A transmission information lacking portion in a pixel block occurring at the upper and lower ends and left and right ends of a screen in the divided pixel blocks, the extrapolation information from image information adjacent to the portion or the latest information of the portion. 2. The image processing apparatus according to claim 1 , further comprising: a transmission information lacking portion image correcting unit that uses the received image information to form the pixel information in the transmission information lacking portion. Video signal note
Encryption device.