JPH11261965A - Image recording device and image reproducing device - Google Patents

Abstract

(57) [Summary] [Problem] To guarantee that recorded image data has not been falsified such as editing after recording, and when reproducing the image data, it is possible to find traces of falsification which can be freely viewed and falsified. A simple image recording device and a simple reproducing device are realized. For example, time information such as year / month / day / hour / minute / second is output from a clock 101, and image information indicating the time information is displayed on a screen of an input image signal by a synthesizer 102. The combined image signal is encrypted by the encryptor 103.
And then recorded as a TV broadcast recording image or the like. When the recorded image is reproduced, the time information is combined with the reproduced image, so that the continuity of time can be easily confirmed, and that the recorded image data has not been tampered with after being recorded. Can be guaranteed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus used in an apparatus / system for transmitting a moving image such as a TV telephone, a TV conference system, a portable information terminal, a digital video disk system, a TV broadcasting system, and the like. More particularly, the present invention relates to an image recording apparatus that retains a state at the time of recording and protects and prevents tampering or the like from being recorded, and a reproducing apparatus that can restore recorded information and confirm that the information has not been tampered with.

[0002]

2. Description of the Related Art In a system for transmitting a moving image such as a TV broadcasting system, a broadcasting station generally makes a CM contract and collects a sponsor fee. However, in order to confirm that the CM has really been broadcast, broadcast
It is necessary for the sponsor to check the broadcast, such as checking the time or checking the recorded video later.

[0003] Therefore, it is conceivable that the broadcast station records its own broadcast and provides it to the sponsor. In this case, it is necessary to guarantee that the recorded data is actually broadcast data, and to falsify the recorded data. It is required to make sure that it is not done. This is because there is a risk that data not used for broadcasting is recorded on a tape and displayed, or that the recorded tape is later edited and changed to a different content. Therefore, there is a need for a system that easily guarantees that image data is broadcast data and that tampering such as editing has not been performed later.

Further, simply recording an image on a tape or the like is not economical because the amount of image data is large. For example, it is inefficient when recording is performed continuously for 24 hours or when recording is performed in units longer than that.

[0005]

As described above, conventionally, it is difficult to guarantee whether recorded data is actually broadcasted data, and that it has not been tampered with. For this reason, a system in which the broadcast station records its own broadcast and provides it to the sponsor could not be realized.

The present invention has been made in view of such circumstances, and guarantees that recorded image data has not been falsified by editing or the like after recording.
It is an object of the present invention to provide an image recording apparatus and a reproducing apparatus that can be freely viewed and that can easily detect a falsified trace.

[0007]

According to the present invention, there is provided an image recording apparatus for recording an input image signal, comprising: a time information output means for outputting time information; Image synthesizing means for synthesizing an image corresponding to the obtained time information on the screen of the input image signal, and generating a synthesized image signal of the time information and the input image. It is characterized by recording a composite image signal.

In this image recording apparatus, for example, time information output means for outputting time information such as year / month / day / hour / minute / second is provided, and image information such as characters indicating the time information is provided. Is combined with a part of the input image signal on the screen, and the combined image signal is recorded as a recorded image of a TV broadcast or the like. When the recorded image is reproduced, the time information is combined with the reproduced image, so that the continuity of time can be easily confirmed, and that the recorded image data has not been tampered with after being recorded. Can be guaranteed.

Further, the image recording apparatus of the present invention further comprises an encrypting means for encrypting the combined image signal generated by the image combining means, and records the encrypted combined image signal. I do. By encrypting and recording the composite image signal in this way, unauthorized editing of the recorded image can be prevented, and when the recorded image is reproduced and confirmed, the decrypted image is correctly decrypted and the correct image is obtained. The presence or absence of tampering can be determined based on whether the output has been made.

Further, the image recording apparatus of the present invention further comprises image input means for inputting the input image signal, wherein the image input means comprises a broadcast receiving apparatus for receiving a broadcast signal. And By limiting the image input means to a broadcast receiving device such as a radio wave receiving device, it is possible to guarantee that the input image signal is actually broadcast data.

Further, the image recording apparatus of the present invention further comprises encoding means for encoding the composite image signal generated by the image compositing means, wherein the encoded composite image signal or the encoded composite image signal is encoded. It is characterized in that the result of encryption of the image signal is recorded. When recording image data as it is, the amount of data is extremely large, and the efficiency is low for long-time recording. Therefore, by compressing and encoding the synthesized image signal, it is possible to solve the problem of the capacity while guaranteeing that the recorded image data has not been falsified by editing or the like after recording.

Further, the image recording apparatus of the present invention further comprises an encoding means for encoding the synthesized image signal generated by the image synthesizing means, and based on the encoding result information of the encoding means, A part of the synthesized composite image signal is encrypted by the encryption means. Even if a synthesized image signal is encoded, a large amount of processing time is required to encrypt all of the encoded synthesized image signals. For example, encoding mode information or an intra-frame encoded code By encrypting only the parts that cannot be restored unless they can be decrypted correctly, such as encrypted images, it is possible to avoid the risk of unauthorized editing and improve the efficiency of the encryption process. It becomes possible.

According to another aspect of the present invention, in an image recording apparatus for recording an input image signal, a time information output means for outputting time information, and an image corresponding to the time information output from the time information output means is input to the input image signal. An image synthesizing unit that synthesizes a signal on a screen to generate a synthetic image signal of time information and an input image, and a feature amount calculation that calculates a feature amount of the image from the synthetic image signal generated by the image synthesizing unit Means, and an encrypting means for encrypting the characteristic amount obtained by the characteristic amount calculating means, wherein the composite image signal and the encrypted characteristic amount are recorded in association with each other. .

In the present invention, an image is not subjected to an encryption process, but a feature amount of the image is calculated and the value is encrypted. This makes it possible to reduce the amount of calculation for encryption. On the playback device side, the encrypted feature value is decrypted, and the result of the decryption is compared with the feature value calculated from the input image.
The presence or absence of tampering can be checked.

[0015]

FIG. 1 is a block diagram of an image recording apparatus according to a first embodiment of the present invention. This image recording apparatus is for recording an image such as a TV broadcast. Input image data 131 is input to the synthesizer 102 together with time information 132 output from the clock 101.

The synthesizer 102 converts the time information 132 into an image signal composed of characters such as characters,
By combining it on the screen of the input image data 131, the image data with time information 133 is created.

The image data 133 with time information is input to the encryptor 103, and after the encryption processing, the output data 1 is output.
34, which is recorded on the recording device. In this case, time information or the like combined with the recorded image data is added as an index for searching for the time information. By using this index, it is possible to selectively search and read out recorded images only in a certain time zone. Instead of the time information, a TV program table or the like may be used as an index.

Here, a public key cryptosystem is used for the encryption. The public key cryptosystem is a system in which encryption is performed with a key known only by an encryptor called a secret key, and the encrypted data is decrypted with a key called a public key to restore the original data. The public key can only be restored and cannot be encrypted. In the present invention, editing and rewriting after recording cannot be performed by utilizing this characteristic.

A feature of the present invention resides in that a time information output device for outputting time information is provided inside and an image obtained by synthesizing the image with an image is encrypted. This part will be described in detail below.

The image recording apparatus has a clock whose setting cannot be changed from the outside, that is, a clock which does not output the same time a plurality of times. The time information output from the clock 101 is composed of, for example, year / month / day / hour / minute / second, and is synthesized on the input image as shown in FIG. Is generated. The synthesizing process is performed on a pixel-by-pixel basis.
1 is overlaid on the screen of the input image data 131 as shown.

Here, the above-mentioned public key encryption method is adopted as the encryption method. The key used for encryption is a secret key, and only the encoder of the present invention can know it. Prevent external access to this key. For example, the whole is configured as a one-chip LSI or one system, and the image recording apparatus itself is sealed. It is assumed that the inside of the dotted line shown in FIG. 1 is inseparable as one system, and each component cannot be accessed from the outside.

As shown in the block diagram of FIG. 2, the reproducing apparatus converts the input encrypted data 231 into the inverse encryptor 201.
To obtain a reproduced image 232. When confirming an image, it can be determined whether the image has been correctly decrypted and a correct image has been output. Further, since time information is combined with the decoded image, it is possible to check whether or not the image has been edited after recording by checking the continuity of time on the playback screen. Since the reproducing side performs the decryption processing using the public key, there may be a plurality of reproducing sides.

FIG. 4 shows an example of application as a system. Data broadcast from a broadcasting station is recorded at a recording station using the image recording device of the present invention. Thereafter, the encrypted recorded data is made public on the network, and a viewer as a confirmer obtains the data via the network, decrypts the data using a public key, and reproduces the image. The network here is not limited to the Internet or intranet, but may be anything. For example, the case where a medium recorded by mail is sent is also included. Since a secret key is required for encryption, it is not possible to use an encryptor in the recording station, but anyone can easily see it because it is possible to decrypt and confirm the contents only with the public key be able to. The secret key inherent in the recording device is a key unique to the device, and cannot be reproduced by a device recorded by a different recording device.

FIG. 5 is a flowchart showing a processing procedure of the image recording apparatus of FIG. First, a broadcast image is captured (step S1). Next, the current time is obtained from the clock 101 (step S2), and the obtained time is converted into an image composed of a character indicating the current time (step S3). Next, a time character is synthesized on the captured image (step S4). This synthesis process
Although it is performed every frame, it is not always necessary to update the time information every frame. For example, the time information may be updated every 15 seconds. In this case, the same time is synthesized on the screen of each scene of a certain continuous 15 seconds.

Thereafter, after the compression encoding process of the composite image is performed by the function described later, the encryption process is performed, and the composite image is recorded using the broadcast time or the program table as an index.

(Effect of the First Embodiment) By utilizing the present invention, it is possible to record a moving image with high reliability. The reliability here means that data cannot be tampered with by performing editing / rewriting after recording. This is very effective when the client of the CM verifies whether the broadcasting station has correctly broadcasted the CM or the like.

Further, by recording a composite image using a broadcast time or a program table as an index, it is possible to read and confirm only a recorded image in a necessary time zone through a network.

(Modification of First Embodiment) In order to guarantee that the input image data is broadcast data, this is realized by limiting the input unit to a TV broadcast radio wave receiving device. . FIG. 6 shows an example of this embodiment.

The broadcast wave 531 is received by the receiver 501. It is assumed that this receiver 501 can receive only broadcast data. For example, it is assumed that a special receiver that receives only a frequency band of a certain broadcasting station does not accept input of other data. It is also possible to support a plurality of broadcasting stations. The data 532 received by the receiver 501 is output from the clock 502 inside the recording device and the synthesizer 50.
3 is synthesized. The synthesized data 534 is output to the encryptor 5
The data is encrypted in 04 and recorded as output data 535 in an external storage device.

When the image data is recorded as it is, the data amount becomes extremely large, and the efficiency is low for long-time recording. Therefore, this problem is solved by compressing and encoding the image. This example is shown in FIG.

In FIG. 7, the broadcast image data 631 received by the broadcast radio receiver 501 is combined with the output of the clock 602 inside the recording device by the combiner 603. The synthesized data 634 is compression-encoded by the encoder 604, the encoded data 635 is encrypted by the encoder 605, and the encoded data 635 is recorded in the external storage device as output data 535.

The feature of this embodiment is that, after synthesizing the time information 633 and the input image 632, the encoder 604 compresses and encodes the encoded data 635. As a result, a significant reduction in the amount of data can be realized. For example, it is only necessary to check whether the broadcast has been made.If the image quality does not matter, if the size of the image is reduced, the image quality is slightly reduced, and the encoding is performed, data can be exchanged even on a telephone line or a narrow line of the Internet. be able to.

FIG. 8 shows an example of a block diagram of a reproducing apparatus corresponding to the image recording apparatus of FIG. The input encrypted signal 731 is decrypted by the decryption device 701 and further decrypted by the image decryption device 702. By outputting and presenting this, a reproduced image is obtained.

A receiver 6 is used as the image recording device of the present embodiment.
Although the example in which 01 is present is shown, this component is not essential and can be used for the image recording apparatus shown in FIG.

Since the encryption of the public key cryptosystem requires a large amount of calculation, it may be difficult in real time to perform encryption processing on all data. Therefore, this problem is solved by encoding only a part of the encoded data when encoding and recording the image.

A moving image is composed of continuous frames. In a normal image encoding method, encoding is sequentially performed on a frame basis. Data encoded in units of frames is represented by, for example, a data string having the configuration shown in FIG.

First, the first method is a method of encrypting only specific information in the encoded data to be output. For example, as shown in FIG. 16, only the mode information indicating the encoding mode is encrypted. If this information is not correctly decrypted, the decrypted image will not be output correctly, so that even if encryption processing is performed only on this information, it is possible to make it resistant to tampering. Similarly, various modifications are possible, such as encrypting only the residual signal.

The second method is to encrypt one frame every n frames, so that the time required for encryption is reduced by 1 / total.
n. The amount of processing is reduced by performing encryption only on a specific frame instead of performing encryption processing every frame. This method can be a method other than simply encrypting every n frames. For example, as shown in FIG. 17, in image coding, an INTRA mode (I Picture) for performing intra-frame coding and an INTE mode for performing inter-frame coding using a difference between frames are used.
The R mode (P Picture) exists. INTR
If the A frame cannot be decrypted, the INTER frame cannot be decrypted. Therefore, only the INTRA frame is encrypted, and the INTER frame is output as it is. Even in this case, the processing amount can be reduced and the same effect can be obtained. Also, instead of an INTRA frame,
It is also possible to encrypt the INTER frame. At this time, it is not necessary to encrypt all the INTRA frames or encrypt all the INTER frames. When it is desired to confirm data in a certain unit, it is sufficient that at least one encrypted frame exists in the section. For example, when it is necessary to check an image at intervals of 15 seconds, a specific frame may be encrypted once every 15 seconds.

Further, it is also possible to use a combination of both methods. FIG. 9 shows a block diagram of the image recording apparatus of the present invention. In FIG. 9, broadcast image data 831 received by broadcast wave receiver 801 is stored in clock 8 inside the recording device.
02 and the combiner 803. The combined data 834 is compression-encoded by an encoder 804, and the encoded data 835 is selectively input to an encryptor 806 by a switch 805, and only a part of the encoded data 835 is encrypted. You. The switching operation by the switch 805 is performed based on the encoding result information of the encoder 804. Thereafter, the output 837 of the encryptor 806 and the encrypted encoded data 835 are switched by the switch 8
By selectively outputting the encoded data string 07, an encoded data string 839 in which only part of the encoded data string 839 is encrypted is generated and recorded in an external storage device. The switching operation by the switch 807 is also performed based on the encoding result information of the encoder 804.

The feature of this example resides in that the switches 805 and 807 are controlled using information obtained by encoding by the image encoder 804. As explained above,
For example, the switch 805 is switched according to the difference between the INTRA frame and the INTER frame. In the case of the INTRA frame, the coded signal is input to the encryptor 806, and in other cases, the coded signal is output as it is. This makes it possible to reduce the amount of calculation for the encryption processing.

FIG. 10 is a block diagram showing an image reproducing apparatus corresponding to the image recording apparatus shown in FIG. Also in this case, the coding mode is first determined by the coding mode determiner 901 from the input signal 931. This controls the switches 902 and 903. For example, INTRA
In the case of a frame, it is input to the encryptor 903 and then to the image decryptor 904. Otherwise, it is directly input to the image decoder 904.

FIGS. 18 and 19 are flowcharts showing the operation of the image recording device of FIG. 9 and the image reproducing device of FIG. Here, I-Picture (INTRA
In this example, it is determined whether to perform encryption based on whether the encryption is performed based on the mode (mode) or P-Picture (INTER mode).

That is, in the image recording apparatus, encoding is performed after synthesizing time information on an input image signal (steps S11, S12, S13), but the encoding mode is INTR.
A determination is made as to whether encryption is to be performed depending on whether the mode is the A mode or the INTER mode (step S14). The frame image encoded in the INTRA mode is subjected to encryption processing (step S15), and is encoded in the INTER mode. The frame image is output as it is without encryption (step S16).

The image reproducing apparatus decodes the encoding mode information of the encoded input image signal to determine whether the image is encoded in the INTRA mode.
It is determined whether the image is encoded in the TER mode (steps S21, S22, S23), and the image encoded in the INTRA mode is decrypted after decryption and output (steps S24, S24). S25, S2
6) Further, the image encoded in the INTER mode is decrypted without being decrypted and output (steps S25 and S26).

(Second Embodiment) FIG. 11 shows a second embodiment of the present invention.
FIG. 3 is a block diagram of the image recording apparatus according to the embodiment. The input image data 1031 is synthesized by the synthesizer 1002 with the time information 1032 output from the clock 1001. The feature amount of the composite data 1033 is calculated by the feature amount calculator 1003. The encryptor 1004 encrypts the calculated feature value 1034 and outputs an encrypted feature value 1035. The composite image 1033 is recorded in association with the encrypted feature value 1035.

In the image reproducing apparatus, as shown in FIG. 12, the encrypted feature value 1131 is decrypted by the decryption device 1101 to obtain the feature value 1132. Also, a feature amount 1134 is calculated by the feature amount calculator 1102 from the input image data 1133. Decrypted feature value 1132
By comparing the feature amount 1134 calculated again from the image and the image with the feature amount comparator 1103, it is confirmed whether or not tampering such as editing has been performed.

(Effect of the Second Embodiment) The present invention is characterized in that a feature amount of an image is calculated and the value is encrypted instead of performing an encryption process on the image. Using this method is effective in reducing the calculation amount of the public key encryption method.

(Modification of Second Embodiment) Feature CHR
Several methods are given below as examples of the calculation method of. 1. Sum of pixel values of image This is given by the following equation (Equation 1).

[0049]

(Equation 1) 2. Sum of pixel values included in a partial region of the image This is given by the following equation (Equation 2).

[0050]

(Equation 2) 3. The sum of the bits of the bit string after image encoding This is given by the following equation (Equation 3).

[0051]

(Equation 3)

4. The bit sequence after image encoding is selected and the sum of bits is calculated. For example, the sum of the bits is obtained using only the mode information of each frame. This is given by the following equation (Equation 4).

[0053]

(Equation 4)

Here, the section in which the feature value is calculated can be set for each frame, and it is also possible to calculate one feature value by grouping several frames. This is expressed by Equation 1 to Equation 4, for example, frame end = fra
It means that n can be freely set as me start + n.

The method of reducing the amount of information by using image coding shown as a modification of the first embodiment can also be used in this case. FIG. 13 shows an example of a block diagram of the image recording apparatus. Synthesized image signal 1 synthesized with time information 1232
233 is encoded by the image encoder 1203. The encoded signal 1237 is output as it is. Further, the image encoder 1203 outputs the encoded information 1234 to the feature calculator 1204. As the encoded information 1234, various methods can be used, including a method of using a restored image signal obtained by decoding an encoded signal inside the image encoder 1203 and a method of using the encoded signal itself. It is. That is, it is assumed that the information required by the feature calculator 1204 is output. The feature amount calculator 1204 calculates a feature amount 1235 from the signal 1234, and
5, and outputs an encrypted feature quantity 1236.

FIG. 14 shows an example of a reproducing apparatus corresponding to the image recording apparatus shown in FIG. A feature of this reproducing apparatus is that an image decoder 1302 is added to the reproducing apparatus of FIG. As a result, an image-encoded signal is received and a decoded image is reproduced. Further, it provides necessary encoding information 1334 to the feature amount calculator 1303.

According to the second embodiment according to this method,
The amount of data to be recorded can be reduced. Also,
As shown in the first embodiment, a configuration having a receiver for receiving a broadcast as input means can be used in the second embodiment.

(Modification of First and Second Embodiments) As a means for confirming that input image data is indeed broadcast, there is a method of recording simultaneously with other data. For example, it is also possible to use a method of recording simultaneously with the broadcast of another station or a time signal of a telephone. In this case, the same encryption can be used for the audio data.

It is of course possible to apply the above-described method to other information such as voice. First
Both the second embodiment and the second embodiment are described on the premise of so-called general broadcasting, but this can be used for a broadcasting service using the Internet, and for distribution of various data such as a video conference and a video phone. .

Although the public key encryption method is used here as the encryption method, the encryption method is not limited to this. The encryption system can be changed by the system using the present invention.

When confirming that the recorded broadcast is temporally continuous on the reproducing side, the image is confirmed by adding a time detecting device which recognizes the time display combined with the reproduced image and reads out the time. FIG. 20 shows an example of an image reproducing apparatus with an automatic determination device that can automatically determine without an inspection by a user. The image signal 1932 decrypted and restored by the inverse encryptor 1901 is reproduced as it is, and the time detector 1902 detects the time display synthesized in the image. Time information 1934 detected by the time detector 1902
Is compared with the time information 1933 input as a reference by the determiner 1903, and it is determined whether or not the time display is correct, and a determination result 1935 is output.

For example, when an image in a specific time zone is acquired from a recording station through a network or the like and is reproduced, the reproduction apparatus generates time information corresponding to the broadcast time of the image as reference time information. By comparing this with the time information 1934 detected by the time detector 1902, it is possible to verify the presence or absence of tampering based on temporal continuity. Also, since the CM provider usually holds the original CM image source, the user does not check the image on the screen,
A device for comparing the decrypted reproduced image with the CM image source may be provided to automatically check the contents of the broadcast image.

In the above description, a case is described in which a dedicated device for recording / reproducing an image is provided. However, an image synthesizing process, an encoding process, an encrypting process, and a reproducing process performed on the image recording side are performed. Decryption processing and decryption processing that are performed can be performed by software, and a simple system can be realized by executing a computer program that performs such processing on a personal computer or workstation. It is.

[0064]

As described above, according to the present invention,
By synthesizing and encrypting the time information with the contents to be recorded, it is possible to prevent the creation of multiple data at the same time, and when reproducing, even if it is edited and tampered with, the trace can be easily recognized. Can be found.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an image recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an image reproducing device corresponding to the image recording device of FIG.

FIG. 3 is a view showing an example of a composite image obtained by the image recording apparatus of FIG. 1;

FIG. 4 is a diagram showing an example of a system using the image recording device of FIG. 1 and the image reproducing device of FIG. 2;

FIG. 5 is a flowchart illustrating a procedure of an image recording process in the image recording apparatus of FIG. 1;

FIG. 6 is a block diagram showing another configuration example of the image recording apparatus according to the first embodiment.

FIG. 7 is a block diagram showing still another configuration example of the image recording apparatus according to the first embodiment.

FIG. 8 is a block diagram showing a configuration example of an image reproducing device corresponding to the image recording device of FIG. 7;

FIG. 9 is a block diagram showing still another configuration example of the image recording apparatus according to the first embodiment.

FIG. 10 is a block diagram showing a configuration example of an image reproducing device corresponding to the image recording device of FIG. 9;

FIG. 11 is a block diagram illustrating a configuration of an image recording apparatus according to a second embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration example of an image reproducing device corresponding to the image recording device of FIG. 11;

FIG. 13 is a block diagram showing an example of another configuration of the image recording apparatus according to the second embodiment.

14 is a block diagram showing a configuration example of an image reproducing device corresponding to the image recording device of FIG.

FIG. 15 is a diagram showing an example of an encoded data string encoded by the image recording apparatus of the present invention.

FIG. 16 is a diagram showing an example of a method of selecting data used for encryption in the image recording apparatus of the present invention.

FIG. 17 is a diagram showing an example of a method of selecting encryption on a frame basis in the image recording apparatus of the present invention.

FIG. 18 is a flowchart illustrating the operation of the image recording apparatus of the present invention.

FIG. 19 is a flowchart illustrating the operation of the image reproducing apparatus according to the present invention.

FIG. 20 is a block diagram showing another example of the configuration of the image reproducing apparatus according to the first and second embodiments of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 ... Clock 102 ... Synthesizer 103 ... Encryption device 131 ... Input image signal 132 ... Time information 201 ... Decryption device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichiro Akiyama 1 Toshiba R & D Center, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa

Claims (15)

[Claims] 1. An image recording apparatus for recording an input image signal, comprising: time information output means for outputting time information; and an image corresponding to the time information output from the time information output means. An image synthesizing means for synthesizing on a screen and generating a synthesized image signal of time information and an input image, wherein the image is recorded by recording the synthesized image signal generated by the image synthesizing means. Recording device. 2. An image recording apparatus according to claim 1, further comprising an encrypting means for encrypting the synthesized image signal generated by said image synthesizing means, and recording the encrypted synthesized image signal. apparatus. 3. The image according to claim 1, further comprising image input means for inputting said input image signal, wherein said image input means comprises a broadcast receiving device for receiving a broadcast signal. Recording device. 4. An encoding means for encoding the composite image signal generated by the image composition means, wherein the encoded composite image signal or the encoded result of the encoded composite image signal is recorded. The image recording apparatus according to claim 1, wherein: 5. An image processing apparatus according to claim 1, further comprising: an encoding unit that encodes the synthesized image signal generated by said image synthesizing unit, wherein one of said encoded synthesized image signals is encoded based on encoding result information of said encoding unit. 3. The image recording apparatus according to claim 2, wherein the unit is encrypted by the encryption unit. 6. The image recording apparatus according to claim 5, wherein only the synthesized image signal encoded by the encoding unit in the intra-frame encoding mode is encrypted by the encryption unit. 7. The image recording apparatus according to claim 5, wherein only encoding mode information included in the encoding result information of said encoding means is encrypted. 8. An image recording apparatus for recording an input image signal, comprising: time information output means for outputting time information; and an image corresponding to the time information output from the time information output means. Image synthesizing means for synthesizing on a screen to generate a synthetic image signal of time information and an input image; and characteristic amount calculating means for calculating a characteristic amount of the image from the synthetic image signal generated by the image synthesizing means. And an encryption unit for encrypting the feature amount obtained by the feature amount calculation unit, wherein the combined image signal and the encrypted feature amount are recorded in association with each other. apparatus. 9. The image recording apparatus according to claim 2, wherein the encryption unit performs encryption using a secret key of a public key encryption method. 10. An image reproducing apparatus for reproducing an image signal recorded by an image recording apparatus for encrypting and recording a composite image signal of time information and an input image, wherein the input encrypted image signal is decrypted. An image reproducing apparatus, comprising: an inverse encryption means, for reproducing the decrypted composite image signal. 11. The encrypted image signal is obtained by encoding the composite image signal and then encrypting the encoded image signal, and decrypts the encoded image signal decrypted by the decryption means. 11. The image reproducing apparatus according to claim 10, further comprising decoding means for performing the decoding. 12. The encrypted image signal is obtained by encoding the composite image signal and then encrypting a part of the encoded image signal based on an encoding mode, and the encrypted image signal is partially encrypted. The image processing apparatus further includes an encoding mode determination unit that determines an encoding mode of the encoded image signal, based on a determination result by the encoding mode determination unit.
12. The image reproducing apparatus according to claim 11, wherein the apparatus is configured to selectively execute a decryption process of an encoded image signal. 13. An image signal recorded by an image recording apparatus for recording as an image signal by associating a composite image signal of time information and an input image with an encrypted characteristic amount of the composite image signal. An image reproducing apparatus for reproducing, an inverse encrypting unit for decrypting the input encrypted characteristic amount, a characteristic amount calculating unit for calculating a characteristic amount from the input synthesized image signal, An image reproducing apparatus comprising: means for comparing the inversely encrypted feature quantity with the feature quantity calculated by the feature quantity calculation means to verify whether or not the recorded image has been edited. 14. The composite image signal is encrypted using a secret key of a public key encryption system, and the inverse encryption unit performs decryption using a public key of a public key encryption system. 13. The image reproducing apparatus according to claim 10, wherein 15. An image reproducing apparatus for reproducing an image signal recorded by an image recording apparatus for recording a composite image signal of time information and an input image, wherein said time information reading means reads time information from the input composite image signal. And an image reproducing apparatus for verifying whether or not the image is a temporally continuous image using a result of reading by the time information reading means.