JPH09163317A - Transmitter and image signal converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the coding efficiency as the entire system by allowing the coding/decoding system configured to have provision for a specific image signal to cope with lots of kinds of composite color video signals and also to convert the signals into signals optimum to coding and decoding. SOLUTION: In the coding/decoding system for an image signal, a converter 10 converting a composite color video signal to a signal optimum to coding is located to a pre-stage of a coder 1 and an inverse converter is placed to a post-stage of a decoder 5. The image signal converter 10 changes processing for Y/C separation or the like depending whether the received image signal is a major image part or a non-image part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for encoding an input image signal in a system for encoding and transmitting / decoding an image signal, or a system for accumulating / reproducing an encoded image signal. The present invention relates to an image conversion device that converts a signal.

[0002]

2. Description of the Related Art FIG. 23 is a block diagram showing a configuration of a conventional encoding device and decoding device. This figure is (corporation corporation)
574 of TTC Standard Volume V Volume 3 Volume Higher Layer Protocol (Encoding Method) (7th Edition) issued by the Telegraph and Telephone Technical Committee
3 is a simplified version of the block diagram (CCITT H.261) of the video codec shown in FIG.

In the figure, 1 is a coding device for coding a composite color video signal input by a coding algorithm determined by international / national recommendations or original specifications, and 2 is a composite device for decoding the coded image signal. A decoding device 3 for outputting a color video signal is an image signal conversion circuit for converting the input signal into an image signal for input to an encoding circuit described later.

Further, 4 is a circuit for encoding the image signal output from the image signal conversion circuit 3, 5 is a decoding circuit for decoding the encoded image signal input from the encoding device 1, 6
Is an image signal inverse conversion circuit that inversely converts the signal decoded by the decoding circuit 5 into a signal of the same format as the composite color video signal input to the encoding device 1. Reference numeral 7 is a composite color video signal input to the encoding device 1, 8 is a composite color video signal generated by the decoding device 2, and 9 is a transmission path.

Next, the operation will be described. The composite color video signal 7 is input to the encoding device 1 and converted by the image signal converting circuit 3 into an image signal format for encoding by the encoding circuit 4. The image signal encoded by the encoding circuit 3 is transmitted to the decoding device 2 via the transmission line 9.
The image signal decoded by the decoding circuit 5 of the decoding device 2 is inversely converted by the image signal inverse conversion circuit 6 and output as a composite color video signal 8.

[0006] Here, when the encoding device 1 complies with the specifications defined by MPEG of the ITU-T recommendation,
The input signal to the encoding circuit 4 specified in this specification is Y
Since it is a component / Cb / Cr component digital signal, when an analog composite signal such as NTSC is input, it is necessary to convert this analog composite signal to a Y / Cb / Cr component digital signal. This conversion processing is performed in the image signal conversion circuit 3.

Regarding the dynamic range of each signal in the conversion performed in the image signal converting circuit 3, the ITU-R Rec. 601. FIG.
Shows an example of an NTSC analog composite signal. In the figure, 13 is a horizontal synchronizing signal, and 14 is a color burst signal. In the figure, the dynamic range of the Y signal is shown. Rec. In 601, 0 to 100 in the figure
It is stipulated that the IRE be assigned to 8-bit 16 to 235.

EDTV-by the EDTV development committee of the Broadcasting Technology Development Council for the purpose of improving the image quality of the NTSC system.
The II method has been developed. This EDTV-II system is described in the Journal of the Television Society of Japan, Vol. 49, no. 9 (1995),
Special edition "EDTV-" in "Image information engineering and broadcasting technology"
II ", pages 1116 to 1135.

In the EDTV-II system, widening of the screen is realized by a letterbox system in which non-image areas are provided above and below the screen and a horizontally long image having a horizontally long aspect ratio is arranged in the main image area. Further, in the non-image area above and below the screen, a vertical high-frequency component or the like required for image quality improvement, which cannot be transmitted in the main image area, is superimposed as an auxiliary signal to realize higher image quality and higher definition. The EDTV system signal is composed of a composite color video signal of a composite form similar to that of the NTSC system, and achieves both transmission path compatibility and receiver compatibility.

Next, the EDTV-II signal will be described. FIG. 2 is a schematic diagram of the EDTV-II signal. EDTV-I as shown in FIG. 3 has 22 lines in the odd field and 285 lines in the even field.
The I identification control signal is multiplexed. 23 to 52 lines and 233 to 262 lines in the odd field and 286 to 31 lines in the even field
The signal of the non-image portion is multiplexed on up to 5 lines and on lines 496 to 525. In addition, 53 to 232 lines in the odd field and 316 to 49 in the even field
The signal of the main picture part is multiplexed up to 5 lines.

FIG. 3 is a schematic diagram of the EDTV-II identification control signal. In the figure, 13 is a horizontal synchronizing signal, 14 is a color burst signal, 15 is a signal in which carrier suppression amplitude modulation is performed on the same frequency as the color subcarrier, and 16 is 4/7 of the color subcarrier.
This is a confirmation signal in which a carrier frequency is amplitude-modulated with a doubled frequency.
Although the EDTV-II signal is partially compatible with the NTSC system, it contains a non-picture portion signal that is not included in the NTSC signal.

FIG. 25 is a diagram showing signals in the non-picture area. The signal in the non-image area is completely different from the signal in the main image area. As shown in the figure, the signal of the non-picture part is obtained by modulating the offset level 0 with the same frequency as the color subcarrier modulated.

Since this signal is not a signal in which the Y signal and the C signal are multiplexed unlike the NTSC signal, even if the Y / C separation is performed, the Y / C separation is not performed properly. For example, if some or all of them are separated as a Y-side signal, the dynamic range of that signal is approximately -1.
5 to 15 IRE, the Rec.
In the case of the image signal conversion circuit conforming to 601, this signal is not converted in the negative range of -15 to 0IRE. Therefore, in the conventional encoding / decoding system, even if the EDTV-II signal is transmitted, the signal in the non-picture area is not properly transmitted.

[0014]

Since the conventional image signal conversion apparatus is premised on inputting only a specific composite color video signal, when different kinds of composite color video signals are input, the signal There are problems that conversion is difficult, or even if conversion is possible, the dynamic range of the signal cannot be fully utilized, or the efficiency of encoding is reduced. Further, even if the image signal has a signal portion that is not suitable for Y / C separation, Y / C
There is also a problem that C separation is performed, the image signal is distorted, and the coding efficiency is reduced.

The present invention has been made in order to solve the above-mentioned problems, and does not change the encoding / decoding device and does not reduce the efficiency of encoding, and different types of video signals can be generated. The first purpose is to enable transmission. A second object is to transmit an image signal having a signal portion that is not suitable for Y / C separation without distorting and without lowering coding efficiency.

[0016]

A transmitter according to a first aspect of the present invention has an image signal conversion device and an encoding device, and encodes and transmits an input image signal. The apparatus has an image signal conversion means for converting an input image signal into a signal suitable for the encoding apparatus according to the type of the input image signal, and the encoding apparatus includes the image signal Coding means for coding the image signal converted by the conversion means.

The transmitter according to the second invention is such that the image signal inputted to the transmitter according to the first invention is an EDTV-II signal.

An image signal conversion apparatus according to a third aspect of the present invention inputs an image signal having signal components corresponding to each of the main image area and the non-image area and converts the image signal into a signal suitable for encoding by the encoder. The Y / C separation means for performing the Y / C separation processing on the input image signal and the Y / C separation means for the Y / C separation means for the signal component corresponding to the main image area. C separation processing is performed, and for the signal component corresponding to the non-image area, Y
A control means for controlling the output without performing the / C separation processing is provided.

An image signal converting apparatus according to a fourth aspect inputs an image signal having a signal component corresponding to each of a main image area and a non-image area and converts the image signal into a signal suitable for encoding by an encoder. First Y / C separation means for performing Y / C separation processing on the input image signal,
A second Y / C that performs Y / C separation processing on the input image signal by a method different from that of the first Y / C separation means.
Separation means and Y / C separation processing is performed on the signal component corresponding to the main picture area by the first Y / C separation means, and signal components corresponding to the non-picture area is processed. The second Y / C separation means is provided with a control means for controlling the Y / C separation processing.

An image signal converting apparatus according to a fifth aspect inputs an image signal having a signal component corresponding to each of the main picture area and the non-picture area and converts it into a signal suitable for encoding by the encoder. And an offset level converting means for converting an offset level with respect to the input image signal, and a signal corresponding to the main image area or / and a signal corresponding to the main image area. The offset level conversion means has a control means for converting the offset level so that the offset level falls within the dynamic range of the encoding device.

An image signal converting apparatus according to a sixth aspect of the present invention inputs an image signal having signal components corresponding to each of the main image area and the non-image area and converts the image signal into a signal suitable for encoding by the encoding apparatus. The level adjusting means for adjusting the dynamic range of the input image signal, and the signal corresponding to the main image area and the signal corresponding to the non-image area have the same dynamic range. As described above, the level adjusting means has a control means for controlling the dynamic range.

An image signal converting apparatus according to a seventh aspect of the present invention converts an input image signal into a signal suitable for encoding in an encoding apparatus, and performs a first sampling with respect to an input analog image signal. First A / D conversion means for A / D conversion according to rate, second A / D conversion means for A / D conversion for input analog image signal at second sampling rate, and input analog image The first A / D conversion means or the second A / D depending on the type of signal
The control means for selecting the conversion means is provided.

An image signal conversion device according to an eighth aspect of the present invention converts an input image signal into a signal suitable for encoding in an encoding device, and is for a chroma signal after Y / C separation. Line thinning-out means for thinning lines, and when the input image signal is an image signal having a signal component corresponding to each of the main image area and the non-image area, with respect to the chroma signal of the input image signal And a control means for outputting the lines without performing thinning processing by the line thinning means.

An image signal converting apparatus according to a ninth aspect inputs an image signal having a signal component corresponding to each of the main image area and the non-image area and converts it into a signal suitable for encoding in an encoding apparatus. In addition, it has a control means for converting the signal component corresponding to the non-image area into a fixed value and outputting the fixed value.

An image signal converting apparatus according to the tenth invention is
A color video signal is converted into a signal suitable for encoding, and when the destination corresponds to the color video signal, the chroma signal of the input color video signal is output, and the destination sends the color video signal. It is provided with control means for controlling to output a fixed value when it does not correspond to a signal.

An image signal conversion apparatus according to the eleventh invention is
An image signal having a signal component corresponding to each of the main image area and the non-image area is input and converted into a signal suitable for encoding in an encoding device, the signal corresponding to the main image area. A signal having a component and a signal having a signal component corresponding to the non-image area are output so as not to be mixed in block units, and if a predetermined number of pixels are insufficient when outputting in block units, the predetermined It is provided with an output means for interpolating and outputting for pixels.

An image signal conversion apparatus according to the twelfth invention is
In the third to eleventh inventions, the image signal input to the image signal conversion device is an EDTV-II signal.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment of the Invention FIG. 1 is a block diagram showing an image transmission system according to an embodiment of the present invention. In FIG. 1, 7 is an input composite color video signal, 10 is a control signal in the input input composite color video signal 7, or a signal other than an image signal is identified, and the signal is converted so as to be optimal for encoding. An image signal conversion device 11 for outputting to the encoding device 1 is provided in the image signal conversion device and identifies a control signal in the input composite color video signal 7 or a signal other than the image signal, and a control signal based on the identification result. A control signal etc. detecting circuit for outputting
It is an image signal conversion circuit for converting a signal so as to be optimum for encoding based on a control signal from the.

Reference numeral 1 is an encoding device for inputting the output of the image signal converting device 10 for encoding, 9 is a transmission line, and 5 is a decoding device for decoding the signal output from the encoding device 1 via the transmission line 9. , 6 is an image signal inverse conversion device that performs the inverse conversion of the image signal decoded by the decoding device 5 with the image signal conversion device 12, and 8 is an output composite color video signal reproduced by the image signal inverse conversion device 6. is there. The input composite color video signal 7 in the embodiment of the present invention is the EDTV-II signal described in detail in the conventional example. Further, the encoding device 1 and the decoding device 5 are ITU-R Recommendation H.264. 261, MPE
A component signal such as G is an object of encoding.

Next, the operation will be described. The image signal conversion device 10 inputs the input composite color video signal 7, and the control signal etc. detection circuit 11 identifies a control signal or a signal other than the image signal in the input composite color video signal 7, and based on the identification result. Output control signal. The image signal conversion circuit 12 converts the input composite color video signal 7 based on the control signal input from the input control signal etc. detection circuit so as to be optimum for encoding, and outputs it. The image signal output from the image signal conversion device 10 is
The data is encoded by the encoding device 1 and output to the transmission line 9.

The decoding device 5 decodes the image signal output from the encoding device 1 via the transmission path 9 and outputs it. The image signal inverse conversion device 6 performs the inverse conversion of the image signal decoded by the decoding device 5 with the image signal conversion device 12, and outputs the output composite color video signal 8.

Next, the image signal converting apparatus 10 will be described in detail. FIG. 4 is a diagram showing a detailed circuit of the image signal conversion apparatus 10. In the figure, 7 is an input composite color video signal, 45 is a Y signal output, 46 is a C signal output, 17 is a sync signal detection circuit for detecting horizontal and vertical sync signals from the composite color video signal, 18 is a line counter, 19 Is EDT
A circuit that detects the V-II identification control signal and controls the selectors 201 and 202 at the timing of the main image portion and the non-image portion, 21 is a Y / C that performs Y / C separation on the input composite color video signal 7. Separation circuit, 402 and 403 are each Y
These are the Y signal output and the C signal output from the / C separation circuit. 4
01 is the same signal as the input composite color video signal 7, 404
Is a fixed value (for example, 0).

Next, the operation of the image signal conversion apparatus 10 will be described. The input composite color video signal 7 is a sync signal detection circuit 1
7, the identification control signal detection circuit 19, and the Y / C separation circuit 21. In the sync signal detection circuit 17,
The vertical / horizontal synchronizing signal is detected, and the line counter 18 is reset and counted up. The identification control signal detection circuit 19 detects the EDTV-II identification control signal multiplexed on the 22nd line and the 285th line, and combines it with the value of the line counter 18 for the signals of the main image portion and the non-image portion, respectively. Take control.

A control method in the odd field will be described with reference to the drawings. FIG. 5 is a timing chart showing a control method for the EDTV-II signal. In the figure,
The identification control signal detection circuit 19 uses 22 lines for the EDTV-I.
When the I identification control signal is detected, the input signal is EDT
It recognizes that it is a V-II signal, and it is 52 from the 23rd line.
In the non-image portion of the line, the selectors 201 and 202 are selected so that the Y signal output 45 and the C signal output 46 output the signal 401 and the signal 404, respectively. Therefore, 2
Y / C separation is not performed for the input composite color video signal 7 in the non-image part of 3 lines to 52 lines, and the input composite color video signal 7 is output as it is from the Y signal output 45. The C signal output 46 outputs a fixed value that maximizes the coding efficiency in each system.

In the main picture portion of lines 53 to 232, the Y signal output 45 and the C signal output 46 are respectively Y
/ C separation circuit Y signal output 402, C signal output 40
The selectors 201 and 202 are selected so as to output 3. For the signals of the non-image part of 233 lines to 262 lines, the Y signal output 45 and the C signal output 46 are the same as the signals of the non-image part of 23 lines to 52 lines, respectively.
01, the selector 201 so that the signal 404 is output,
Select 202. The same applies to the even field.

As described in the prior art, the EDTV-
The signal of the non-picture part of II is Y signal and C like NTSC system.
Since the signals are not multiplexed, it is unclear how they will be separated by Y / C separation. As a result, when there is a difference in encoding between the Y-side signal and the C-side signal, when decoded, the reproduction efficiency of the signal becomes extremely poor. In addition, the encoding method becomes very complicated. Therefore, as shown in the embodiment of the present invention, Y / C separation is not performed on the signal of the non-image part, and the Y side is forced to
Alternatively, by outputting to the C side, signal distortion due to Y / C separation can be prevented, reproduction efficiency can be improved, and encoding can be simply performed.

Next, the operation when the NTSC signal is input to the image signal converter 10 will be described with reference to the timing chart of FIG. In addition, for NTSC signals, EDTV-I
Unlike the I signal, the identification control signal is not multiplexed on the 22nd and 285th lines.

When the NTSC signal is input, 22
No identification control signal is detected on the line. Therefore,
In this case, the identification control signal detection circuit detects the 26th to 26th lines.
In the effective line area of 2 lines, Y signal output 45,
The selectors 201 and 202 are selected so that the C signal output 46 outputs the Y signal output 402 and the C signal output 403 from the Y / C separation circuit 21, respectively. This is EDT
The operation is the same as the operation for the main image portion of 53 to 232 lines of the V-II signal.

These Y signal output 45 and C signal output 46
Is input to the encoding device 1. The encoding device 1 performs predetermined encoding and transmits. The encoded image signal is decoded by the decoding device 5, and the image signal inverse conversion device 6 performs the reverse conversion of the image signal conversion device 10 to generate a final composite color video signal 8.

As described above, according to the invention described in the embodiments of the present invention, in particular, the image signal conversion device is a coding means for the input image signal according to the type of the input image signal. Since the encoding device includes an image signal conversion unit that applies conversion processing to a suitable signal, and the encoding device includes an encoding unit that encodes the image signal converted by the image signal conversion unit, the existing encoding It is possible to transmit a plurality of different types of image signals without changing the device and without lowering the coding efficiency.

Further, the image signal input to the transmitter is ED.
Since the TV-II signal is used, a plurality of different types of image signals can be transmitted with respect to the EDTV-II signal without changing the existing coding device and without lowering the coding efficiency.

Further, Y / C is applied to the input image signal.
Y / C separation means for performing the separation processing and Y / C separation processing for the signal components corresponding to the main image area are performed by the Y / C separation means for the signal components corresponding to the non-image area. Is equipped with a control means for controlling the Y / C separation means to output without performing the Y / C separation processing. Therefore, it is possible to prevent the signal distortion due to the Y / C separation and improve the reproduction efficiency. Can be simplified.

In the embodiment of the present invention, the composite color video signal 7 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit.

Further, in this example, the control signal in the composite color video signal is automatically detected and the image signal is converted, but the input signal is, for example, EDTV-II.
If it is known in advance that it is either a signal or an NTSC signal, it is possible to perform it manually instead of performing automatic detection.

Embodiment 2 of the Invention FIG. 7 is a diagram showing an image signal conversion device according to the second embodiment of the present invention. The input composite color video signal in the embodiment of the present invention is an EDTV-II signal, and the encoding device 1 and the decoding device 5
As in the case of the second embodiment of the invention, H.264. 26
1. It is assumed that a component signal such as MPEG is a target of encoding. In the figure, 7, 17 to 19 etc., FIG.
The components denoted by the same reference numerals as those in FIG. 4 indicate the same or corresponding parts of the configuration in FIG.

Reference numerals 211 and 212 denote Y / C separation circuits A and B, respectively, which have different Y / C separation systems. The Y / C separation circuit A is, for example, a two-dimensional Y / C separation circuit or a three-dimensional Y / C separation circuit using a comb filter, and the Y / C separation circuit B is, for example, a band-pass filter or a low-pass filter It is a dimension Y / C separation circuit. 701 and 703 are Y signal output and C signal output from the Y / C separation circuit 211 respectively, and 702 and 704 are Y / C separation circuit 21 respectively.
2 is a Y signal output and a C signal output.

Next, the operation will be described. FIG. 8 is a timing chart showing the operation of the image signal conversion device according to the second embodiment of the invention. The identification control signal detection circuit 19 detects the identification control signal on line 22. The identification control signal detection circuit 19 selects the selectors 702 and 704, which are the outputs from the Y / C separation circuit B212, in the period of the non-image portion of 23 lines to 52 lines.
Control 1 and 202.

During the period of the main image portion from the 53rd line to the 232th line, the selector 20 selects the outputs 701 and 703 from the Y / C separation circuit A211.
Control 1 and 202. Also, from 233 line to 26
Y / C separation circuit B
The selectors 201 and 202 are controlled so as to select the outputs 702 and 704 from 212.

According to the invention described in the embodiments of the present invention, the first Y / C separation means for performing the Y / C separation processing on the input image signal, and the above described for the input image signal. Y / C by a method different from the first Y / C separation means
Second Y / C separation means for performing separation processing, and Y / C separation processing for the signal component corresponding to the main image area by the first Y / C separation means to obtain the non-image area. Since the second Y / C separation means is provided with control means for controlling the Y / C separation processing for the signal component corresponding to the area, the Y signal of the main image portion and the non-image portion, C It is possible to reduce distortion due to Y / C separation for each signal.

For example, in the main picture portion, the accuracy of motion compensation prediction by the Y signal can be improved, and in the non-picture portion, most of the signal components can be output as the Y side or the C side.

In the embodiment of the present invention, the composite color video signal 7 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit.

Further, in this example, the control signal in the composite color video signal is automatically detected and the image signal is converted, but the input signal is, for example, EDTV-II.
If it is known in advance that it is either a signal or an NTSC signal, it is possible to perform it manually instead of performing automatic detection.

Third Embodiment of the Invention FIG. 9 is a diagram showing an image signal conversion device according to a third embodiment of the present invention. The input composite color video signal in the embodiment of the present invention is an EDTV-II signal, and the encoding device 1 and the decoding device 5
As in the case of the second embodiment of the invention, H.264. 26
1. It is assumed that a component signal such as MPEG is a target of encoding. In the figure, 7, 17 to 19 etc., FIG.
The components denoted by the same reference numerals as those in FIG. 4 indicate the same or corresponding parts of the configuration in FIG.

Reference numerals 231 and 232 denote an offset level conversion circuit A and an offset level conversion circuit B having different offset level conversion levels. The offset level conversion circuit A has the input / output characteristics shown in FIG. B has the input / output characteristics shown in FIG. In FIGS. 11 and 12, 13 is a horizontal synchronizing signal,
Reference numeral 14 is a color burst signal, and 1001 is a signal of a non-image portion. In this way, the offset level conversion circuit A does not convert the offset level and outputs the input signal as it is. On the other hand, in the offset level conversion circuit B, the offset level is converted so as to shift by 15 IRE to the plus side as a whole. Offset level conversion circuits 231, 2
32 can also be constituted by a ROM, for example. Reference numeral 901 denotes a signal output whose offset level has been converted.

Next, the operation will be described with reference to FIG. FIG. 10 is a timing chart showing the operation of the image signal conversion device. The identification control circuit 19 controls the selector 20 so as to select the output from the offset level conversion circuit B232 in the effective pixel area during the period of the non-image part of 23 lines to 52 lines and 233 lines to 262 lines. Therefore, in this case, -15IRE ~
An input signal having a range of 15 IRE is shifted to the positive side by 15 IRE as shown in FIG.
It is output as a signal having a range of ˜30 IRE.

Further, in the effective pixel area during the period of the main image portion of 53 lines to 232 lines, the selector 20 is controlled so as to select the output from the offset level conversion circuit A231. In this case, since the offset level conversion circuit A231 does not convert the offset level with respect to the input signal as shown in FIG. 11, the input signal is output as it is.

As described above, according to the invention described in the embodiments of the present invention, particularly, the offset level converting means for converting the offset level with respect to the input image signal and the main image area are provided. For the signal or / and the signal corresponding to the non-image area, the offset level converting means has a control means for controlling to convert the offset level so as to fall within the range of the dynamic range of the encoding device, so that the transmission is performed. It is possible to transmit the signal of the non-image part, which was difficult.

In the embodiment of the present invention, the composite color video signal 7 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit.

Further, in this example, the control signal in the composite color video signal is automatically detected and the image signal is converted, but the input signal is, for example, EDTV-II.
If it is known in advance that it is either a signal or an NTSC signal, it is possible to perform it manually instead of performing automatic detection.

In the embodiment of the invention described above, the offset level conversion circuit A231 does not convert the offset level of the input signal and outputs it as it is, so it need not be provided as a circuit. On the other hand, the offset level may be converted for the convenience of processing on the main screen.

Fourth Embodiment of the Invention FIG. 13 is a diagram showing an image signal converting apparatus according to Embodiment 4 of the present invention.
The input composite color video signal in the embodiment of the present invention is an EDTV-II signal, and the encoding device 1 and the decoding device 5 are H.264 as in the case of the second embodiment of the invention. 26
1. It is assumed that a component signal such as MPEG is a target of encoding. In the figure, 7, 17 to 19 etc., FIG.
The components denoted by the same reference numerals as those in FIG. 4 indicate the same or corresponding parts of the configuration in FIG.

Reference numeral 241 is a level expansion circuit A, and 242 is a level expansion circuit B. The level expansion circuit B has a higher level expansion degree than the level expansion circuit A 241, and a larger dynamic range is obtained when the same signal is input. Can be obtained and functions as a level adjusting means. Also, 1
301 is an output signal of which the level of the input composite color video signal is expanded. The level expansion circuits 241, 242 can also be configured by ROM, for example.

Next, the operation will be described with reference to FIG. FIG. 14 is a timing chart showing the operation of the image signal conversion device. The identification control circuit 19 controls the selector 20 so as to select the output from the level expansion circuit B242 in the effective pixel area during the period of the non-image part of 23 lines to 52 lines and 233 lines to 262 lines.

Further, the selector 20 is controlled so as to select the output from the level expansion circuit A241 in the effective pixel area during the period of the main image portion of 53 lines to 232 lines. In this case, the level expansion circuit A241 level expands the signal of the main image portion, which is the input signal, at a degree of expansion lower than that of the level expansion circuit B242.

As described in the prior art, the signal of the non-picture part has a smaller dynamic range than the signal of the main picture part, and if the same coding is applied to the non-picture part and the main picture part, The error becomes relatively large. Accordingly, the level adjusting means adjusts the dynamic range of the input image signal, and the level adjusting means adjusts the dynamic range so that the signals of the main image portion and the non-image portion have the same dynamic range. Since the control means for controlling is provided, it is possible to reduce the error particularly in the non-image area. Further, in the encoding device, it is not necessary to change the encoding method of the non-image part and the main image part, and the encoding control and the circuit can be simplified.

Embodiment 5 of the Invention FIG. 15 is a diagram showing an image signal converting apparatus according to Embodiment 5 of the present invention.
The input composite color video signal in the embodiment of the present invention is an EDTV-II signal, and the encoding device 1 and the decoding device 5 are H.264 / AVC signals as in the case of the first embodiment of the invention. 26
1. It is assumed that a component signal such as MPEG is a target of encoding. In the figure, the components denoted by the same reference numerals as those in FIG. 4 such as 17 to 19 indicate the same or corresponding parts of the configuration in FIG.

Reference numeral 1501 denotes a composite color video signal, 1502
Is an analog composite color video signal, and 1503 is a digital output signal. 251 is an A / D converter with a sampling rate other than 14.31818 MHz, 25
2 is A with a sampling rate of 14.31818MHz
/ D converter.

Next, the operation will be described. EDTV as an input composite color video signal 1501 to the image signal converter
-II signal is input. The identification control signal detection circuit 19 detects the EDTV-II identification control signal in the EDTV-II signal and instructs the selector 20 to output the composite color video signal 1
A / D regardless of whether 502 is a non-image area or a main image area
Select the output of converter 252.

On the other hand, the identification control signal detection circuit 19 is the EDT.
When the V-II identification control signal is not detected, it is arbitrary to select either output of the A / D converters 251 and 252, and the output is output as the output 1503.

In the embodiment of the present invention, the signal of the non-picture part which is modulated at the same frequency as the color subcarrier is sampled at a frequency which is an integral multiple (in this example, an integer is 4) of A / The signal distortion due to D conversion can be suppressed to a minimum.

As described above, according to the invention described in the embodiments of the present invention, the first analog-to-digital conversion is performed on the input analog image signal at the first sampling rate.
Second A / D conversion means, and second A / D conversion for the input analog image signal at the second sampling rate
The A / D conversion means and the control means for selecting the first A / D conversion means or the second A / D conversion means according to the type of the input analog image signal are included in the A / D conversion means. It is possible to limit the signal distortion due to.

In FIG. 15, the composite color video signal 150 is shown.
1 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit. In this example,
Although the control signal in the composite color video signal is automatically detected and the image signal is converted, it is also possible to manually perform the conversion without performing the automatic detection.

Sixth Embodiment of the Invention 16 is a diagram showing an image signal converting apparatus according to Embodiment 6 of the present invention.
The input composite color video signal in the embodiment of the present invention is an EDTV-II signal, and the encoding device 1 and the decoding device 5 are H.264 / AVC signals as in the case of the first embodiment of the invention. 26
1. It is assumed that a component signal such as MPEG is a target of encoding. In the figure, the components denoted by the same reference numerals as those in FIG. 4 such as 17 to 19 indicate the same or corresponding parts of the configuration in FIG.

Reference numeral 1601 denotes an input composite color video signal, 16
Reference numeral 02 is a chroma signal input, 26 is a chroma signal line thinning circuit for thinning chroma signals, and 1603 is a chroma signal output. When the input 1602 is a composite color video signal, a Y / C separation circuit may be added to this signal.

Here, generally, the encoding device to which the image signal converting device is connected has a line of 4: 2: 2,
Some of them are 4: 2: 0. Therefore, as an image signal conversion device, when an NTSC signal is input, it is 4: 2: 2 when the encoding device is 4: 2: 2, or 4: 2.
In the case of 2: 0, it is necessary to convert it to 4: 2: 0. On the other hand, when the EDTV-II signal is input, such conversion is unnecessary and it is not necessary to thin out the lines.

Next, the operation will be described. In this circuit, when the identification control signal detection circuit 19 detects the EDTV-II identification control signal, line thinning (4: 2: 2 to 4: 2) is applied to the chroma signal regardless of the non-image part and the main image part. : Conversion to 0) is not performed. When the identification control signal detection circuit 19 does not detect the EDTV-II identification control signal, it is possible to select whether to perform thinning or not.

As described above, according to the invention described in the embodiments of the present invention, the line thinning means for thinning the lines from the chroma signal after Y / C separation and the input image signal are the main images. When the image signal has a signal component corresponding to each of the partial area and the non-image area, the line thinning means outputs the line to the chroma signal of the input image signal without performing thinning processing. Since the means is provided, it is possible to prevent the distortion caused by the calculation when the line thinning-out is performed on the signal of the non-image portion, and it is possible to prevent the information of the signal from being lost when the thinning-out is performed.

In FIG. 16, the composite color video signal 160
1. The chroma signal 1602 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit. In this example, the control signal in the composite color video signal is automatically detected and the image signal is converted.
It is also possible to do it manually without automatic detection.

Seventh Embodiment of the Invention FIG. 17 is a diagram showing an image signal converting apparatus according to Embodiment 7 of the present invention.
The input composite color video signal in the embodiment of the present invention is an EDTV-II signal, and the encoding device 1 and the decoding device 5 are H.264 / AVC signals as in the case of the first embodiment of the invention. 26
1. It is assumed that a component signal such as MPEG is a target of encoding.

In the figure, the components denoted by the same reference numerals as those in FIG. 4, such as 17 to 19, indicate the same or corresponding parts of the configuration in FIG. 1701 is an input composite color video signal, 1702
Is an output signal.

Next, the operation will be described. FIG. 18 is a timing chart showing the operation of the image signal conversion device. In the identification control signal detection circuit 19, the input signal 17
When the identification control signal is detected during 01, the selector 20 is controlled so as to select the output of the fixed value (no signal state) during the period of the non-image portion. Further, during the period of the main image portion, the selector is controlled so that the signal of the input 1701 is selected as it is and output to the output.

As described above, according to the invention described in the embodiments of the present invention, since the control means for converting the signal component corresponding to the non-picture area into a fixed value and outputting the fixed value is output, transmission of an extra signal is performed. Can be prevented, and the regeneration efficiency can be improved as a whole system. Specifically, the non-picture section is in a no signal state, and, for example, the decoding side system is EDTV-II.
By transmitting more necessary signals instead of transmitting extra signals when it does not correspond to signals,
The regeneration efficiency can be improved as a whole system.

In FIG. 17, the composite color video signal 170 is shown.
1 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit. In this example,
Although the control signal in the composite color video signal is automatically detected and the image signal is converted, it is also possible to manually perform the conversion without performing the automatic detection.

Eighth Embodiment of the Invention FIG. 19 is a diagram showing an image signal conversion device according to the eighth embodiment of the present invention.
The input composite color video signal in the embodiment of the present invention is an NTSC signal, and the encoding device 1 and the decoding device 5 are the same as in the case of the first embodiment of the invention. 261, M
It is assumed that a component signal such as PEG is the target of encoding.

Reference numeral 1901 designates a destination identification circuit, 1902 designates Y.
Chroma signal input after / C separation, 1903 is a chroma signal output.

Next, the operation will be described. When the destination identifying circuit 1901 determines that the destination corresponds to the color signal, the selector 20 is controlled so that the chroma signal input 1902 is output as it is. If the destination identifying circuit 1901 determines that the destination does not support color signals, the selector 20
Is controlled so that the fixed value is output as it is.
In this case, the output is in the no signal state.

Here, switch means or the like can be considered as means for identifying the destination. In this case, it is necessary to manually check the information of the destination. Also, for the destination,
There is also a method of requesting to transmit information regarding adaptability of a destination to a color signal, and identifying based on a reply signal from the destination.

According to the invention described in the embodiments of the present invention, a destination identification means for identifying whether or not the destination corresponds to a color video signal, and the destination identification means for the destination is the color video signal. Since the control means is provided so as to output a fixed value when it is determined that the signal does not correspond to the signal, it is possible to prevent the transmission of an extra signal and improve the reproduction efficiency of the entire system.

In FIG. 19, a composite color video signal 190
2 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit.

Ninth Embodiment of the Invention 20 is a diagram showing an image signal converting apparatus according to Embodiment 9 of the present invention.
The input composite color video signal in the embodiment of the present invention is an EDTV-II signal, and the encoding device 1 and the decoding device 5 are H.264 / AVC signals as in the case of the first embodiment of the invention. 26
1. It is assumed that a component signal such as MPEG is a target of encoding.

Reference numeral 2001 denotes a composite color video signal, 2002
Is a digital composite color video signal, and 2003 is a digital output image signal. When the input 2002 is an analog composite color video signal, an A / D converter may be added to this signal. Reference numeral 17 is a synchronization signal detection circuit, 19 is an identification control signal detection circuit, 27 is a write address control circuit for the memory 29, 28 is a control circuit for the read address and selector 20, and 30 is an interpolation signal generation circuit.

The input signal 2001 is the sync signal detection circuit 1
7. Input to the identification control signal detection circuit 19. The input signal 2002 is input to the memory 29. Reading from the memory 29 is performed in block units of a predetermined number of pixels. The sync signal detection circuit 19 detects vertical / horizontal sync signals and resets / counts up the write address control unit 27 and the read address / selector control unit 28.

The operation when the discrimination control signal detection circuit 19 discriminates the discrimination control signal will be described. FIG. 21 shows a part of the pixel structure of the input image and a part of the pixel structure of the output image. The horizontal direction in the drawing is the horizontal direction, and the vertical direction is the line direction. A is a pixel in the non-image part, B is a pixel in the main image part, and C is a pixel generated by interpolation. Figure 21 at memory write
Writing is performed with the pixel configuration shown in FIG. When reading
This is performed in units of blocks having a predetermined number of pixels, but in this example, when dividing into blocks, the number of pixels in the non-image portion is short by two lines in the line direction.

When the insufficient pixels for two lines are read from the memory, the pixels generated by the interpolation pixel generation circuit 30 are interpolated and then output to the output 2003. The interpolation generation circuit 30 can also output a fixed value.

As described above, according to the invention described in the embodiments of the present invention, a signal having a signal component corresponding to the main image area and a signal having a signal component corresponding to the non-image area are respectively blocked. The main block having different characteristics is output to the same block because the output is provided so as not to be mixed in units and the output is provided by interpolating and outputting the predetermined pixels when the predetermined pixels are insufficient when outputting in the block unit. It is possible to prevent the deterioration of the coding efficiency because the signals of the image part and the non-image part do not coexist.

In FIG. 20, a composite color video signal 200
1 can be either an analog signal or a digital signal. In that case, each circuit is either an analog or digital circuit. In this example,
Although the control signal in the composite color video signal is automatically detected and the image signal is converted, it is also possible to manually perform the conversion without performing the automatic detection.

Tenth Embodiment of the Invention An application example of another system of the present invention will be described with reference to the drawings. 22 is a block diagram showing an image transmission system according to Embodiment 10 of the present invention. In FIG. 22, the components designated by the same reference numerals as those in FIG. 1 indicate the same or corresponding portions as those in FIG. Reference numeral 31 is a device for accumulating encoded image signals.

Next, the operation will be described. Encoding device 1
The image signal encoded by the above method is stored in the storage device 31 in the short term or the long term, and the storage device 31 stores it when necessary.
The data is reproduced by using the extracting and decoding device 5 and the image signal inverse conversion device 6. In this example, the control signal in the composite color video signal is automatically detected and the image signal is converted, but it is also possible to manually perform the conversion without performing the automatic detection.

In the embodiment of the invention described above, the single storage device 31 is provided between the encoding device 1 and the decoding device 5 so as to connect them, but only the encoding device 1 is provided. Storage device 3 for storing in a recording medium such as FD or optical disk
1 is provided, and the storage device 3 is provided in the decoding device 5 via a recording medium.
A reading device for reading the contents stored in 1 may be provided. The image signal may be a character signal multiplexed.

[0100]

The transmitter according to the first aspect of the present invention has an image signal conversion device and an encoding device, and encodes and transmits an input image signal. The image signal conversion device comprises:
The image signal converting means for converting the input image signal into a signal suitable for the encoding means according to the type of the input image signal is provided, and the encoding device includes the image signal converting means. Since it has a coding means for coding the converted image signal, a plurality of different kinds of image signals are transmitted without changing the existing coding device and without lowering the coding efficiency. be able to.

Since the transmitter according to the second invention uses the EDTV-II signal as the image signal input to the transmitter according to the first invention, it is necessary to change the existing coding device for the EDTV-II signal. It is possible to transmit a plurality of different types of image signals without any loss of coding efficiency.

The image signal conversion apparatus according to the third invention inputs an image signal having a signal component corresponding to each of the main image area and the non-image area and converts it into a signal suitable for encoding by the encoding apparatus. The Y / C separation means for performing the Y / C separation processing on the input image signal and the Y / C separation means for the Y / C separation means for the signal component corresponding to the main image area. C separation processing is performed, and for the signal component corresponding to the non-image area, Y
Since the control means for controlling the output so as not to perform the / C separation processing is provided, the signal distortion due to the Y / C separation can be prevented, the reproduction efficiency can be improved, and the encoding can be simply performed. .

The image signal converting apparatus according to the fourth aspect of the invention inputs an image signal having signal components corresponding to the main image area and the non-image area, respectively, and converts it into a signal suitable for encoding by the encoder. First Y / C separation means for performing Y / C separation processing on the input image signal,
A second Y / C that performs Y / C separation processing on the input image signal by a method different from that of the first Y / C separation means.
Separation means and Y / C separation processing is performed on the signal component corresponding to the main picture area by the first Y / C separation means, and signal components corresponding to the non-picture area is processed. Since the control means for controlling the second Y / C separation means to perform the Y / C separation processing is provided, the distortion due to the Y / C separation is applied to the Y signal and the C signal of the main image portion and the non-image portion. Can be reduced.

The image signal conversion apparatus according to the fifth invention inputs an image signal having a signal component corresponding to each of the main image area and the non-image area and converts it into a signal suitable for encoding by the encoder. And an offset level converting means for converting an offset level with respect to the input image signal, and a signal corresponding to the main image area and / or a signal corresponding to the non-image area as described above. Since the offset level conversion means has a control means for controlling the offset level to be converted so as to fall within the range of the dynamic range of the encoding device, it is possible to transmit the signal of the non-image part, which was difficult to transmit.

An image signal conversion apparatus according to a sixth aspect of the present invention inputs an image signal having a signal component corresponding to each of the main picture area and the non-picture area and converts it into a signal suitable for encoding by the encoder. The level adjusting means for adjusting the dynamic range of the input image signal, and the signal corresponding to the main image area and the signal corresponding to the non-image area have the same dynamic range. Since the control means for controlling the dynamic range to be adjusted by the level adjusting means is included, it is possible to reduce the error particularly in the non-image area.

An image signal conversion apparatus according to a seventh aspect of the present invention converts an input image signal into a signal suitable for encoding in an encoding apparatus, and performs a first sampling for an input analog image signal. First A / D conversion means for A / D conversion according to rate, second A / D conversion means for A / D conversion for input analog image signal at second sampling rate, and input analog image The first A / D conversion means or the second A / D depending on the type of signal
Since the control means for selecting the conversion means is provided, the A / D
It is possible to limit signal distortion due to conversion.

An image signal conversion apparatus according to the eighth invention is for converting an input image signal into a signal suitable for encoding in an encoding apparatus, and for a chroma signal after Y / C separation. Line thinning-out means for thinning lines, and when the input image signal is an image signal having a signal component corresponding to each of the main image area and the non-image area, with respect to the chroma signal of the input image signal Since there is a control means for outputting the line without performing the thinning processing by the line thinning means, the distortion caused by the calculation when the line thinning is performed on the signal of the non-image part is prevented, and the signal when thinning is performed. It is possible to prevent the loss of information held by.

The image signal conversion apparatus according to the ninth invention inputs an image signal having signal components corresponding to each of the main image area and the non-image area, and converts it into a signal suitable for encoding by the encoding apparatus. However, since it has a control means for converting the signal component corresponding to the non-picture area into a fixed value and outputting the fixed value, it is possible to prevent the transmission of an extra signal and improve the reproduction efficiency of the entire system.

An image signal conversion apparatus according to the tenth invention is
An image signal conversion device for converting a color video signal into a signal suitable for encoding, wherein when the transmission destination corresponds to the color video signal, a chroma signal of the input color signal is output, and the transmission destination is Since the control means for controlling to output the fixed value when the color video signal is not supported is provided, the transmission of the extra signal can be prevented and the reproduction efficiency of the entire system can be improved.

An image signal conversion apparatus according to the eleventh invention is
An image signal having a signal component corresponding to each of the main image area and the non-image area is input and converted into a signal suitable for encoding in an encoding device, the signal corresponding to the main image area. A signal having a component and a signal having a signal component corresponding to the non-image area are output so as not to be mixed in block units, and if a predetermined number of pixels are insufficient when outputting in block units, the predetermined Since it is provided with an output unit for interpolating and outputting for pixels, signals of a main image part and a non-image part having different characteristics do not coexist in the same block, and it is possible to prevent a decrease in encoding efficiency.

An image signal converting apparatus according to the twelfth invention is
In the third to eleventh inventions, since the image signal input to the image signal conversion device is the EDTV-II signal, the effects of the respective inventions can be exerted on the EDTY-II.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an image transmission system according to a first embodiment of the invention.

FIG. 2 is a schematic diagram of an EDTV-II signal.

FIG. 3 is a schematic diagram of an EDTV-II identification control signal.

FIG. 4 is a diagram showing a circuit of the image signal conversion device according to the first embodiment of the invention.

FIG. 5 is a timing chart showing an operation of the image signal conversion device according to the first embodiment of the invention.

FIG. 6 is a timing chart showing the operation of the image signal conversion apparatus according to the first embodiment of the invention.

FIG. 7 is a diagram showing a circuit of an image signal conversion device according to a second embodiment of the invention.

FIG. 8 is a timing chart showing an operation of the image signal conversion device according to the second embodiment of the invention.

FIG. 9 is a diagram showing a circuit of an image signal conversion apparatus according to a third embodiment of the invention.

FIG. 10 is a timing chart showing an operation of the image signal conversion device according to the third embodiment of the invention.

FIG. 11 is a diagram showing input / output characteristics of the offset level conversion circuit B according to the third embodiment of the invention.

FIG. 12 is a diagram showing input / output characteristics of an offset level conversion circuit A according to a third embodiment of the invention.

FIG. 13 is a diagram showing a circuit of an image signal conversion device according to a fourth embodiment of the invention.

FIG. 14 is a timing chart showing the operation of the image signal conversion device according to the fourth embodiment of the invention.

FIG. 15 is a diagram showing a circuit of an image signal conversion device according to a fifth embodiment of the invention.

FIG. 16 is a diagram showing a circuit of an image signal conversion device according to a sixth embodiment of the invention.

FIG. 17 is a diagram showing a circuit of an image signal conversion device according to a seventh embodiment of the invention.

FIG. 18 is a timing chart showing an operation of the image signal conversion device according to the seventh embodiment of the invention.

FIG. 19 is a diagram showing a circuit of an image signal conversion apparatus according to an eighth embodiment of the invention.

FIG. 20 is a diagram showing a circuit of an image signal conversion device according to a ninth embodiment of the invention.

FIG. 21 is a diagram showing an operation of the image signal conversion device according to the ninth embodiment of the invention.

FIG. 22 is a diagram showing an image transmission system according to a tenth embodiment of the invention.

FIG. 23 is a diagram showing a conventional image transmission system.

FIG. 24 is a diagram showing an NTSC analog composite signal.

FIG. 25 is a diagram showing a signal of an EDTV-II non-image part.

[Explanation of symbols]

1 Encoding Device, 5 Decoding Device, 6 Image Signal Inverting Device, 10 Image Signal Converting Device, 11 Control Signal etc. Detection Circuit, 19 Identification Control Signal Detection Circuit, 12 Image Signal Conversion Circuit, 21 Y / C Separation Circuit, 231 , 232 offset level conversion circuit, 241,242 level expansion circuit, 251,252 A / D converter, 26 chroma signal line thinning circuit, 31 storage device.

Claims (12)

[Claims] 1. An image signal conversion device and an encoding device are provided,
A transmitter for encoding and transmitting an input image signal, wherein the image signal conversion device converts the input image signal into a signal suitable for the encoding device according to the type of the input image signal. A transmitter comprising: an image signal conversion unit that performs processing, wherein the encoding device includes an encoding unit that encodes the image signal converted by the image signal conversion unit. 2. The image signal input to the transmitter is E
The transmitter according to claim 1, wherein the transmitter is a DTV-II signal. 3. An image signal conversion device for inputting an image signal having signal components respectively corresponding to a main image area and a non-image area and converting the image signal into a signal suitable for encoding in an encoder. Y / C that performs Y / C separation processing on the captured image signal
The separating means and Y / Y for the signal component corresponding to the main image area.
A control means for performing Y / C separation processing by the C separation means and controlling the signal component corresponding to the non-image area to be output without performing the Y / C separation processing by the Y / C separation means. Image signal converter provided. 4. An image signal conversion device for inputting an image signal having a signal component corresponding to each of a main image area and a non-image area and converting the image signal into a signal suitable for encoding in an encoder. The first Y / C separation means for performing the Y / C separation processing on the input image signal and the Y / C separation processing for the input image signal by a method different from the first Y / C separation means. Second Y / C to do
The separating means and the first component for the signal component corresponding to the main image area
Y / C separation processing is performed by the Y / C separation means, and the second Y / C separation processing is performed on the signal component corresponding to the non-image area.
An image signal conversion device comprising control means for controlling the C separation means to perform Y / C separation processing. 5. An image signal conversion device for inputting an image signal having signal components respectively corresponding to a main image area and a non-image area and converting the image signal into a signal suitable for encoding in an encoding device, An offset level converting means for converting an offset level to the image signal, and a signal corresponding to the main image area or / and a signal corresponding to the main image area by the offset level converting means. An image signal conversion apparatus having a control means for converting an offset level so that the offset level falls within a dynamic range of the conversion apparatus. 6. An image signal conversion device for inputting an image signal having signal components respectively corresponding to a main image area and a non-image area and converting the image signal into a signal suitable for encoding in an encoding device, Level adjusting means for adjusting the dynamic range of the image signal, and the level adjusting means so that the signal corresponding to the main image area and the signal corresponding to the non-image area have the same dynamic range. An image signal conversion device having a control means for controlling a dynamic range by means of the above. 7. An image signal conversion device for converting an input image signal into a signal suitable for encoding in an encoding device, wherein A / D conversion is performed on the input analog image signal at a first sampling rate. A first A / D conversion unit, a second A / D conversion unit for A / D converting the input analog image signal at a second sampling rate, and a second A / D conversion unit according to the type of the input analog image signal. 1 A / D
An image signal conversion device comprising a control means for selecting the conversion means or the second A / D conversion means. 8. An image signal conversion device for converting an input image signal into a signal suitable for encoding in an encoding device, wherein line thinning means for thinning a line for a chroma signal after Y / C separation. And when the input image signal is an image signal having a signal component corresponding to each of the main image area and the non-image area, the line thinning-out line is applied to the chroma signal of the input image signal. An image signal conversion apparatus having a control means for outputting the signal without performing thinning processing. 9. An image signal conversion apparatus for inputting an image signal having signal components corresponding respectively to a main image area and a non-image area and converting the image signal into a signal suitable for encoding in an encoder. An image signal conversion apparatus having a control means for converting a signal component corresponding to a non-image area into a fixed value and outputting the fixed value. 10. An image signal conversion device for converting a color video signal into a signal suitable for encoding, wherein a chroma signal of the input color video signal is output when the transmission destination corresponds to the color video signal. However, the image signal conversion device is provided with a control means for controlling to output a fixed value when the destination does not correspond to the color video signal. 11. An image signal conversion apparatus for inputting an image signal having signal components corresponding respectively to a main image area and a non-image area and converting the image signal into a signal suitable for encoding in an encoder. A signal having a signal component corresponding to the main image area and a signal having a signal component corresponding to the non-image area are output so as not to be mixed in block units, respectively, and
An image signal conversion apparatus comprising: an output unit that interpolates and outputs a predetermined pixel when the predetermined pixel is insufficient when outputting in block units. 12. The image signal processing device according to claim 3, wherein the image signal input to the image signal conversion device is an EDTV-II signal.