JP3087563B2 - Digital image data transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for transmitting digital image data, and is applied to a VTR as an application example.

[0002]

2. Description of the Related Art As a magnetic recording / reproducing apparatus (hereinafter abbreviated as VTR) for digitally encoding and recording / reproducing a video signal, a D1-V which uses a signal to be recorded as a component signal.
TR, D2-VTR and D3-V as composite signals
TR has been put to practical use. All of these VTRs are sampled at a rate sufficiently higher than the video signal bandwidth,
The data is quantized by 8 bits and recorded on a magnetic tape.

However, these VTRs sample the NTSC signal or PAL signal of the current broadcasting system or the luminance signal (Y) at 13.5 MHz and the chrominance signals (Pb, Pr) at 6.75 MHz, respectively. Two signals are recorded.

On the other hand, a next-generation broadcasting system is about to be started recently. These broadcasting systems are EDTV2 system or H
This is the D method. In order to cope with these new broadcasting systems, which have several times the amount of information as the current broadcasting system, they are compressed by high-efficiency coding using the correlation of image data, and the current VTR is used.
A recording system has been developed. Especially EDTV2
The method is progressive camera, progressive monitor,
VTRs have not yet been developed, even though they have already been developed. As a VTR of the EDTV2, for example, D1-
At present, it is operated using two VTRs.

A conventional digital signal recording device (Japanese Patent Laid-Open No.
According to Japanese Patent Application Laid-Open No. -14468, a double-scanned video signal is converted into two interlaced video signals, compressed to １ ／, and recorded on a current 4-2-2 VTR.

[0006]

However, in the above-mentioned conventional digital signal recording apparatus, for example, a double-scanned video signal is converted into two interlaced video signals and then compressed to １ ／, so that the SNR is low. There was a problem that it was not enough compared with the method of the invention.

In a broadcasting system, a general 4-
In addition to the 2-2 signal, a Key signal that is frequently used in editing is added, and a 4-2-2-4 system is needed.
However, in the conventional digital signal recording device, Ke
The y signal is not mentioned.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a high-performance digital image data transmission apparatus which can handle a plurality of types of video signals.

[0009]

In order to solve the above-mentioned problems, a digital image data transmission apparatus according to the present invention comprises: a plurality of types of digital image data input terminals; A first dividing unit that divides the plurality of types of digital image data into blocks; a first dividing unit that divides the plurality of types of digital image data into blocks; Selecting means for selecting the second dividing means; block coding means for performing block coding on digital image data output from the selecting means for each of the blocks divided by the first and second dividing means; Data transmission means for outputting digital image data output from the encoding means at a predetermined transmission rate.

The first dividing means and the second dividing means use a common memory, and the method of dividing the blocks is switched by the first memory controlling means and the second memory controlling means, respectively.

Further, the digital image data transmitting apparatus according to the present invention comprises an input terminal for N kinds (N is a natural number of 2 or more ) of digital image data, and at least one group.
Contains two or more types of digital image data
Then, the N kinds of digital image data are K pieces (K is
1 ≦ K <data classification means for classifying a group of a natural number) satisfying N, for each of the groups, each classified daisy
Dividing means for dividing the image data into blocks each having a predetermined number of pixels so as to include the digital image data, and block coding the digital image data output from the dividing means for each of the blocks divided by the dividing means. And a data transmission means for outputting digital image data output from the block encoding means at a predetermined transmission rate.

[0012]

According to the present invention, for example, when progressive digital image data is input as two systems of 4-2-2 signals, two systems are blocked together by the first dividing means, and two interlaces are formed. Is input as two-system 4-2-2 signals, they are separately blocked by the second dividing means. Further, the data is encoded for each block by the block encoding unit, and the data is compressed and transmitted at a predetermined transmission rate by the data transmission unit.

Further, for example, a progressive video signal has two systems in a 4-2-2 format, and its Key signal has a 4--0-0 format (a color difference signal portion is blank, and data is inserted only into a luminance signal portion). When two types of image data of a total of four types are input, the classification means classifies the data into a group of progressive video signals and a group of key signals,
Image data of two systems each separately by dividing means
Is blocked to contain Further, the data is encoded for each block by the block encoding unit, and the data is compressed and transmitted at a predetermined transmission rate by the data transmission unit.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS At present, as one method of EDTV2, 4-2-2
-4 system is considered. In the 4-2-2-4 method, sampling is performed at twice the sampling frequency in the horizontal direction.
This is a signal obtained by converting a so-called 8-4-4 signal that has been double-scanned in the vertical direction. The conversion is performed by adding a progressive component of a luminance signal (Y) as a vertical component reinforcement signal to a 4-2-2 video signal of the current interlace system.
-2-2-4-4 system. In this case, the color difference signal is subjected to band compression by passing through a vertical filter.

Also, in the current system, the 4-2-2 system, a key signal is newly added to the 4-2-2 signal because of the necessity of various editing, and the post-production is performed as the 4-2-2-4 system. Etc. operate an editing system. Due to the needs in the market described above, a VTR of the 4-2-2-4 system has been long-awaited. In the first embodiment of the present invention, the EDTV
2-4-2-4 system for Key2, 4-2-2-4 for Key signal system
Both methods provide high-performance image quality.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a 4-2-2-4 digital image data transmission apparatus according to a first embodiment of the present invention.

The uncompressed 4-2-2-4 system is transmitted using two 4-2-2 digital interfaces defined in the CCIR601 recommendation. The first 4-2-2 digital interface is an EDTV2 system 4-2-2-
Both the 4-system and the 4-2-2-4 of the Key signal system are digital interfaces of 4-2-2 signals of interlaced signals. The second 4-2-2 is a EDTV2 system in which a luminance component has a progressive component in a luminance signal portion. The luminance signal is inserted, and the color difference signal portion is blank. In the Key signal method, a Key signal is inserted into a luminance signal portion, and a color difference signal portion is blank.

In FIG. 1, reference numeral 1 denotes an input terminal of the first 4-2-2 digital image data, which is an EDTV2 system, Ke.
For both y signal systems, input interlaced 4-2-2 signals. Reference numeral 2 denotes an input terminal for the second 4-2-2 digital image data. In the case of the EDTV2 system, a progressive component is input.
In the case of the Key signal system, a Key signal is input. 3 is 2
First dividing means 4 for independently dividing the input signals inputted from the two input terminals 1 and 2 into blocks, respectively, and divides the input signals inputted from the two input terminals 1 and 2 into two blocks. The second dividing means 5 performs the output signal of the first dividing means 3 in the case of the Key signal system,
In the case of the two system, the selecting means for selecting the output signal of the second dividing means 4 is used. The output of the selecting means 5 is applied to the blocks divided by the first and second dividing means 3 and 4 by DCT, DPCM, etc. Block encoding means 7 for processing the image data, and quantizes the image data block-encoded by the block encoding means 6,
Data transmission means 8 for making the transmission rate constant by variable length coding or the like, and 8 is an output terminal of the digital image data whose data transmission means 7 has a constant rate.

The operation of the digital image data transmission apparatus configured as described above will be described. First digital image data input from input terminal 1 and input terminal 2
The input second digital image data is input to the first dividing means 3 and is divided into blocks. FIG. 2 is a schematic diagram of the blocking of the first dividing means 3 and the second dividing means 4, and the input digital image data is represented in two dimensions in the horizontal and vertical directions corresponding to the TV screen. In the drawing, sample_No indicates the sample number of valid 720 samples of one horizontal line, and represents 1 to 12. The line No. indicates the line number of the effective 255 lines of one field, and represents 1 to 12.
The block division technique in the first division means 3 is shown in the middle part of FIG. As shown in the figure, the two sets of digital image data of ○ and ● are separately blocked to a size of (4 * 4). The method of block division in the second division means 4 is shown in the lower part of the figure. As shown in FIG.
The two digital images of and ○ are alternately inserted for each line and are blocked to a size of (4 * 4). In the first dividing means 3 or the second dividing means 4, (4 *
The digital image data blocked to the block size of 4) is input to the selection means 5. The selecting means 5 selects the output of the first dividing means 3 when the input of 4-2-2-4 of the Key signal system is performed, and selects the output of the EDTV2 system.
When -2-2-4 is input, the output of the second dividing means 4 is selected. The digital image data output from the selecting means 5 is input to a block coding means 6 and is block-coded for each of the blocks divided by the first and second dividing means 3 and 4. As a block coding technique, an orthogonal transform such as DCT is used, which converts digital image data into a frequency domain, and converts the digital image data into digital data that can be subjected to band compression. Further, the digital image data output from the block encoding means 6 is input to a data transmission means 7, and the digital image data which has been block-encoded by the block encoding means 6 is quantized, variable-length coded, etc. At a predetermined transmission rate and output from the output terminal 8.

As described above, in this embodiment, when 4-2-2-4 of the Key signal system is input, the digital image data of the two systems ○ and ● are separately reduced to the size of (4 * 4). Blocked. The EDTV2 system 4-2-2-
When 4 is input, the digital image data of the two systems ○ and ● are alternately inserted for each line and are blocked to the size of (4 * 4). Therefore, according to 4-2-2-4 of the EDTV2 system, the correlation between the L line of the interlace part and the L line of the progressive part is smaller than the correlation between the L line (L is a natural number) of the interlace part and the (L + 1) line of the interlace part. Since the correlation is high, the coding efficiency can be increased by the blocking method of the second dividing unit 4. Also, in the 4-2-2-4 of the Key signal system, the correlation between the L line (L is a natural number) of the interlace portion and the (L + 1) line of the interlace portion is determined by the relationship between the L line of the interlace portion and the L line of the Key signal. Since the correlation is higher, it is possible to increase the coding efficiency by the blocking method of the first dividing unit 3.

It is needless to say that it is better to add an error correction parity to the data transmission means 7.

FIG. 3 shows a configuration diagram of a second embodiment of the present invention. In the figure, the first division means 3, the second division means 4, and the selection means 5 of the first embodiment are realized by a memory and its control means. 2, reference numerals 1 and 2 denote input terminals for two-system digital image data as in FIG. 1, 10 denotes a memory for writing two-system digital image data, and 11 denotes digital image data output from the memory 10 in the middle of FIG. A first memory control means for controlling the two systems of digital image data to be separately divided as shown in FIG.
As shown in the lower part of FIG. 2, the second memory control means 13 for synthesizing and dividing the digital image data of two outputs for each line as shown in the lower part of FIG. Selectors for selecting the memory control means 11 and 12 according to the input digital image data.
Is the same as

The operation of the digital image data transmitting apparatus according to the second embodiment having the above-described configuration will be described below.

Input terminal 1 and input terminal 2
The first digital image data and the second digital image data of the system are written into the memory 10, divided as shown in FIG. 2, and read out from the memory 10. In this embodiment, when 4-2-2-4 of the Key signal system is input, the output of the first memory control unit 11 is selected by the selector 13 and the memory 10 is controlled. EDTV2
When the system 4-2-2-4 is input, the selector 13
Selects the output of the second memory control means 12 to control the memory 10. Further, the digital image data read by blocking from the memory 10 is input to the block encoding means 6. The following operation is the same as that of the first embodiment of the present invention.

Next, the first and second memory control means 11,
The control method 12 will be described in more detail. FIG.
FIG. 3 is a schematic diagram showing first and second digital image data corresponding to a TV screen. 4 is the digital image data input from the input terminal 1 and the right diagram is the input terminal 2
5 shows digital image data input from the digital camera. Each digital image data is handled with four lines as one unit. In this embodiment, since the blocking is performed in the size of (4 * 4), one line of 720 valid samples is divided every four samples, and one line is configured as 180 blocks / line.

FIG. 5 is a memory map of the present embodiment. The memory of the present embodiment is composed of two memories, a memory 1 for writing first digital image data and a memory 2 for writing second digital image data. Input digital image data for four lines is sequentially written into each memory. In the figure, d1 (m, n)
(M and n are natural numbers) is m of the first digital image data.
The digital image data of the n-th block of the line is shown.
d2 (m, n) (m and n are natural numbers) indicates the digital image data of the n-th block of the m-th line of the second digital image data. The first digital image data is stored in memory 1 as d1
(1,1), ……, d1 (1,180), d1 (2,1), ……, d1 (2,180), d1 (3,
.., D1 (3,180), d1 (4,1),..., D1 (4,180). The second digital image data is stored in the memory 2 as d2 (1,1),..., D2 (1,180), d2 (2,1),.
0), d2 (3, 1),..., D2 (3, 180), d2 (4, 1),..., D2 (4, 180). When reading from the memory, when the first memory control means is selected, as shown in FIG.
｛D1 (1,1), d1 (2,1),… ,, d1 (4,1)｝, ｛d1 (1,2),…, d1
(4,2)｝, …… d1 (1,180), …… d1 (4,180)｝, ｛d2 (1,1),
.. D2 (4,1)},... {D2 (1,180),... D2 (4,180)}. One block of the block coding in this case is {d1 (1, n), d1 (2, n), d1 (3, n), d1 (4, n)} (n is a natural number and a constant value inside the block) D2 (1, n), d2 (2, n), d2
(3, n), d2 (4, n)｝ (n is a natural number and a constant value inside the block). When the second memory control means is selected, as shown in FIG. 5, ５d1 (1,1), d2 (1,1), d1 (2,1),
d2 (2,1)}, {d1 (1,2), d2 (1,2), d1 (2,2), d2 (2,2)}, ... {d1
(1,180), d2 (1,180), d1 (2,180), d2 (2,180)}, {d1 (3,1), d2
(3,1), d1 (4,1), d2 (4,1)}, ……… {d1 (3,180), d2 (3,180),
In the order of d1 (4,180), d2 (4,180)}, the memory 1 and the memory 2 are multiplexed and read out by the blocks in {}. One block of the block coding in this case is ｛d1
(1, n), d2 (1, n), d1 (2, n), d2 (2, n)} (n is a natural number and a constant value inside the block) or ｛d1 (3, n), d2 (3 , n), d1 (4, n), d2
(4, n)｝ (n is a natural number and a constant value inside the block). By switching the control of the memory as described above, as shown in FIG. 2, the Key signal system 4-2-2-
4 is input, the blocking shown in the middle part of FIG. 2 is performed, and when 4-2-2-4 of the EDTV2 system is input, the blocking shown in the lower part of FIG. 2 is performed.

Next, a third embodiment of the present invention will be described. In the third embodiment, the above EDTV2 signal and its Ke
This is a device for compressing and transmitting the y signal. In the figure, 21 is an input terminal of an interlace component of a video signal, 22 is an input terminal of a progressive component of a video signal, 2
3 is an input terminal of the interlace component of the Key signal, 24
Is an input terminal for the progressive component of the Key signal. 2
5 is a data classifying means for classifying the video signal inputted from each input terminal, 26 and 27 are data dividing means for dividing the data-classified video signal into blocks in the group, and 6, 7, and 8 are FIG. Is the same as The operation of the digital image data transmission device configured as described above will be described below.

The interlace components of the video signals input to the input terminals 21, 22, 23, 24, the progressive components of the video signals, the interlace components of the Key signal, Ke
The progressive component of the y signal is input to the data classification means 25, and the interlaced component of the video signal and the progressive component of the video signal are classified into a first group, and the interlaced component of the Key signal and the progressive component of the Key signal are classified into a second group.
Is classified as a group. The video signals of the first group classified by the data classification unit 25 are
6, the video signal of the second group is divided by the data dividing means 27.
, And are respectively blocked as shown in the lower part of FIG. The image data blocked by the data dividing units 26 and 27 is input to the block encoding unit 6, is subjected to block encoding for each block, and is input to the data transmission unit 7, and the transmission rate is set to a predetermined transmission rate.

As described above, in the present embodiment, the input four types of video signals are classified into a first group and a second group for each of two types of video signals having relatively high correlation. Are blocked together by data division means. Therefore, it is possible to make maximum use of the correlations of the four types of video signals, and it is possible to obtain high image quality when restoring image data transmitted at a predetermined transmission rate.

[0030]

As described above, according to the digital image data transmission apparatus of the present invention, when two types of input digital image data are highly correlated with the two types of image data by the data dividing means, two types of image data are obtained. Blocking of data is performed, and when two types of image data have low correlation, blocking is performed separately and block coding is performed. Therefore, optimal block coding can be performed according to input image data. Therefore, a high-quality image can be obtained upon decoding.

When N types of image data are input, the data classification means groups the image data with relatively high correlation, and the data division means divides each group into block units of block coding. Perform block coding. Therefore, it is possible to perform block coding by making maximum use of the correlation between the input N types of image data. Therefore, a high-quality image can be obtained when decoding.

[Brief description of the drawings]

FIG. 1 is a block diagram of a transmission apparatus for digital image data according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of input / output digital image data of the data dividing means of FIG. 1;

FIG. 3 is a block diagram of a digital image data transmission apparatus according to a second embodiment of the present invention;

FIG. 4 is a schematic diagram of input digital image data.

5 is a schematic diagram of a memory map of the memory of FIG. 3 and output data of the memory.

FIG. 6 is a block diagram of a digital image data transmission device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input terminal of 1st digital image data 2 Input terminal of 2nd digital image data 3 1st division means 4 2nd division means 5 Selection means 6 Block coding means 7 Data transmission means 10 Memory 11 1st Memory control means 12 Second memory control means 13 Selector 25 Data classification means 26, 27 Data division means

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/91-5/956 H04N 7/24-7/68 H04N 9/79-9/898 H04N 11 / 00-11/24

Claims (3)

(57) [Claims] An input terminal for inputting a plurality of types of digital image data; first dividing means for separately dividing the plurality of types of digital image data into blocks; A second division unit for dividing the digital image data into blocks each having:
Selecting means for selecting the first dividing means or the second dividing means; and outputting the digital image data output from the selecting means to the first dividing means.
A block encoding unit that performs block encoding for each of the blocks divided by the division unit or the second division unit; and a data transmission unit that outputs digital image data output from the block encoding unit at a predetermined transmission rate. A digital image data transmission device comprising: 2. An input terminal for a plurality of kinds of digital image data, a memory for writing the plurality of kinds of digital image data, and a memory for controlling the memory so as to separately divide the plurality of kinds of digital image data into blocks. 1 memory control means, 2nd memory control means for controlling the memory so as to collectively divide the plurality of types of digital image data into blocks, and
A selector for selecting the first memory control means or the second memory control means; a block coding means for performing block coding on digital image data read from the memory for each divided block; Data transmission means for outputting digital image data output from the block encoding means at a predetermined transmission rate. 3. An input terminal for N kinds (N is a natural number of 2 or more ) of digital image data, and at least one group has two or more kinds of digital image data.
The N types of digital image data are K (K is a natural number satisfying 1 ≦ K <N ) so that the image data is included.
Data classifying means for classifying the digital image data into groups; and digital image data classified for each group.
A dividing unit that divides the digital image data output from the dividing unit into blocks each having a predetermined number of pixels so as to include the block; and a block encoding unit that performs block encoding for each block divided by the dividing unit. A data transmission means for outputting digital image data output from the encoding means at a predetermined transmission rate.