JPS63273272A - Modulation/demodulation system - Google Patents

Abstract

PURPOSE:To realize the protection of an author's copyright or the secrecy of information, by modulating/demodulating a digital signal based on code information in which a prescribed number is encoded. CONSTITUTION:The image pickup signal of an object by a digital electronic still camera is changed to a serial digital signal by an A/D converter 7 and a parallel-serial converter 8, etc., and is supplied to the exclusive OR circuit of a modulator 9. To the exclusive OR circuit, a circular pseudo random number code in which a numeral with three digits, etc., set at a code input device 10 is processed at an M series generator, etc., incorporated in the circuit 9 after being converted to binary data is supplied, and the serial digital signal is modulated by the code, and is written on a picture memory 11. Reproduced data read out from the memory 11 is demodulated similarly, and since no demodulation is performed until the same number as that at the time of modulation is inputted, it is possible to protect the author's copyright and the secrecy of the information.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Use) The present invention relates to a modulation/demodulation system, and is particularly suitable for various image recording and reproducing systems that record and reproduce image information via a recording medium.

(Prior Art) An electronic still camera that converts optical information received by an image sensor such as a CCD (charge-coupled device) array into an electrical signal and records it on a recording medium such as a small magnetic disk (floppy disk). In recent years, various modulation and demodulation systems have been proposed, such as an electronic still camera system, which includes an imaging device such as the above and an image reproducing device that reproduces a recorded image signal.

Conventionally, as a method for recording still images, a silver halide photographic method in which still images are directly recorded on a photosensitive film has been common. In silver halide photography, recorded images are stored in the form of film or prints, and the recorded images themselves can be visually recognized from the recording medium. For this reason, in the silver halide photography method, it was easy to recognize the copyright of the photographer's recorded images.

However, in recent years, a method of converting a still image into a time-series electrical signal and then recording it electrically, magnetically, or optically on a recording medium (hereinafter referred to as an electronic recording method) has improved in terms of ease of signal processing, etc. It has been attracting attention since. In such electronic recording systems, it is generally impossible to visually recognize the recorded image itself from the recording medium.

(Problems to be Solved by the Invention) Therefore, in the electronic recording system, a problem arises in that the copyright of the photographer's recorded images is not widely recognized. In particular, in digital electronic recording systems in which recorded images are recorded as digital signals, there is little deterioration due to duplication, and a method for protecting individual copyrights is considered essential.

Furthermore, electronic recording methods have begun to be used to record image information such as documents, blueprints, and designs that must be kept confidential from third parties; However, there is also the problem that it is not easy to maintain confidentiality.

In view of the above-mentioned problems, the present invention ensures the protection of copyright and the confidentiality of information by making it impossible to reproduce the image content recorded by the photographer without the permission of the photographer. The purpose is to provide a modulation/demodulation system that can achieve this.

[Means for solving problems]

To achieve this object, the present invention comprises code input means for encoding a predetermined number to form code information; modulation means for modulating an input digital signal based on the code information;
It is characterized by comprising demodulation means for demodulating the modulated signal into the original digital signal based on code information.

Further, the present invention is characterized in that it includes a code input means for encoding a predetermined number to form code information, and a modulation means for modulating a human-powered digital signal based on the code information.

Further, the present invention is characterized in that it includes code manual means for coding a predetermined number to form code information, and demodulation means for demodulating an input digital signal based on the code information.

[Effect]

In the present invention, if the same number is not input during signal modulation and demodulation, normal signals (for example, image data) cannot be demodulated. This makes it possible to protect information, prevent infringement of personal interests due to copying, etc., and prevent highly confidential information from being copied or reproduced to ensure the safety and profits of companies, etc.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 5 show the circuit configuration of an embodiment in which the present invention is applied to a digital electronic still camera system.

First, in FIG. 1 showing an example of the overall circuit configuration of a digital electronic still camera, 1 is a subject, 2 is a photographic lens, 3 is a shutter that passes or blocks the light rays from the subject 1 that have passed through the photographic lens 2; Reference numeral 4 denotes an imaging device such as a CCD array on which the light beam from the subject 1 that has passed through the shutter 3 forms an image.

A system control device 5 outputs a shutter opening/closing signal 5a for controlling the shutter 3 and a clock control signal 5b for controlling the clock control device 6.

The clock control device 6 receives an image sensor control signal 6a, an A/D
It outputs a conversion control signal 6b, a P/S conversion control signal 6C1 modulator control signal 6d, and a memory control signal 6e.

Reference numeral 7 denotes an A/D converter that A/D (analog/digital) converts the image signal read out from the image sensor 4 according to the above-mentioned image sensor control signal 6a, and converts the image signal read out from the image sensor 4 according to the A/D conversion control signal 6b. converts the analog signal from the 8-bit digital signal into an 8-bit digital signal. A P/S converter 8 converts the 8-bit digital signal from the A/D converter 7 into a serial signal in accordance with a P/S (parallel/serial) conversion control signal 6C. 9 is a modulator that modulates the serial signal from the P/S converter 8 as described later; lO
is a code input device for manually entering a recitation code (recitation number) into the modulator 9.

The serial signal from the P/S converter 8 is modulated in accordance with the modulator control signal 6d by the modulator 9 initialized by the code data from the code input device IO. The output No. 3 of the modulator 9 is read and recorded in an image memory 11 such as a removable cassette type or card type semiconductor memory (IC memory) in accordance with the memory control signal 6e.

FIG. 2 shows details of the structure of the code input device 10 and modulator 9 of FIG. 1 described above. In this figure, 9a is a modulator 9
9b is an EX-OR circuit (exclusive OR circuit) of the modulator 9. The output of the P/S converter 8 and the output of the M-sequence generator 9a are exclusive ORed in an EX-OR circuit 9b and output to the image memory 11. Reference numeral 10a is a recitation number setter having buttons such as a numeric keypad provided on the code manual device IO, and reference numeral 10b is a binary converter for converting the set value from the recitation number setter 10a into a binary number. By the output of the binary converter 10b,
Initial value setting for the M sequence generator 9a is performed.

FIG. 3 shows an example of the overall configuration of an image reproducing apparatus to which the present invention is applied, which reproduces image information in the image memory 11 described above. In the figure, reference numeral 12 denotes a reproduction control device, which outputs a memory read signal 12a, a demodulator control signal 12b, an S/P (serial/parallel) conversion signal 12C1, and a DHA (digital/analog) conversion signal 12d. A demodulator 13 demodulates a signal read out from the image memory 11 described above in accordance with the memory readout signal 12a. Further, the demodulator 13 is initialized by code data (reciting number) from a code manual device 1O having a configuration similar to that shown in FIG. 2, and demodulates the signal as described later in accordance with the demodulation control signal 12b described above.

14 converts the output of the demodulator 13 into the above-mentioned S/P conversion control signal 1.
It is an S/P converter that performs S/P conversion according to 2c, and 15
converts the output of the S/P converter 14 to the D converter controller No. 1 described above.
This is a D/A converter that performs D/A conversion according to 2d.

The output of the D/C converter 15 is supplied as a reproduction signal 16 to a display device or a printer device (not shown), and is output therefrom.

FIG. 4 shows details of the structure of the demodulator 13 of FIG. 3 described above. In this figure, 13a is an M sequence generator, and its M
The primitive polynomial of the sequence is generated by the above-mentioned M-sequence generator 9 on the camera side.
It is the same as a. 13b is an EX-OR circuit. The M-sequence generator 13a is initialized by the output of the binary converter 10b of the code manual device IO, and receives the demodulator control signal 1.
2b to generate an M-sequence signal. An exclusive OR of the output signal from the image memory 11 and the output signal from the M-sequence generator 13a is obtained by the EX-OR circuit 13b.

FIG. 5 shows an example of the configuration of the M-sequence generator 9a of FIG. 2 described above. The one shown in FIG.
An M-sequence signal with a period of 1023 can be generated by setting the initial values of the registers .about.X(1) and repeating left shifts one clock at a time according to the modulator control signal 6d. Reference numeral 19 is a mod 2 adder, which is composed of an EX-OR circuit. Note that the initial setting value must be excluded if all registers in (XO%
For the 000 recitation numbers, initial setting values must be associated with 1023 patterns, excluding the case where each register (xo-xs) is all 0. Furthermore, the M-sequence generator 13a in FIG. 4 can also be realized with a configuration similar to that in FIG. 5.

FIG. 6 shows the output timing of each control signal in the embodiment shown in FIG.

Next, the operation of the embodiment of the present invention will be explained with reference to FIGS. 1 to 6.

First, the operation of a digital electronic still camera will be described. In the configuration shown in FIG. 1, light rays from the subject 1 are imaged on the image sensor 4 via the photographic lens 2 while the shutter 3 is open (shutter open period). The system control device 5 issues an operation command to the shutter control device 6 using the clock control signal 5b following the time when the shutter 3 changes from the open state to the closed state due to the shutter opening/closing signal 5a (see FIG. 6). With this operation command, the clock control device 6
generates each control signal 6a to 6e at the timing shown in FIG. The image of the subject 1 formed on the image sensor 4 is converted into an electrical signal and input to the A/D converter 7 according to the image sensor control signal 6a.

The A/D converter 7 converts the image signal from the image sensor 4 into an 8-bit digital signal according to the A/[1 conversion control signal 6b, and inputs the signal to the P/S converter 8.

The P/S converter 8 converts the 8-bit digital signal from the A/D converter 7 into a serial signal according to the P/S conversion control signal 6c, and inputs the serial signal to the modulator 9.

The modulator 9 receives data from the code input device lo ([1a
The serial signal (serial image signal) from the P/s converter 8 is modulated according to the recording code data), and the modulated signal is stored in the image memory 11 according to the memory write signal 6e. That is, as shown in FIG. 2, if the operator inputs a 3-digit number in the recitation number setting device 10a, the binary converter 10b converts the 3-digit number into a 10-bit binary number. Convert. M sequence generator 9a
(See Figure 5) generates an M sequence signal (maximum length sequence signal) which is a cyclic pseudo-random number with synchronization of 210-1,
As its initial value, lO which is the output of the binary converter 10b
Adopts bit binary numbers. Modulator control signal 6d (No.
6), the M-sequence signal output from the M-sequence generator 9a is combined with the output signal (serial image signal) of the P/S converter 8 by the EX-OR circuit 9b.
d2 (modulo 2) is added, and from the modulator 9, M
A digital image signal modulated with a sequence signal is obtained.

In this way, the digital image signal modulated by the M-sequence signal, which is a cyclic pseudo-random number, is stored in the image memory 11, so even if the image memory 11 is applied to a normal image reproducing device, the original image cannot be reproduced. .

Next, the operation of the image reproducing apparatus according to the embodiment of the present invention will be described. In the configuration shown in FIG. 3, the modulated image information stored in the image memory 11 is read out as a modulated digital image signal in accordance with the memory readout signal 12a from the reproduction control device 12, and is manually input to the demodulator 13. be done. The demodulator 13 receives data from the code input device 10 (
0! The modulated digital image signal is demodulated according to the S/P conversion control signal 12c, and the demodulated signal is input to the S/P converter 14 as a serial digital image signal. 8-bit image signals are output from the S/P converter 14 in parallel. Furthermore, the 0/8 converter 15 converts this 8-bit parallel image signal into an analog image signal according to the conversion control signal 12d, and outputs it as a reproduction signal 16.

Furthermore, the operation of the demodulator 13 will be described in detail with reference to FIG. This is manually set as the initial setting value of the sequence generator 13a. The M-sequence generator 13a outputs an M-sequence signal according to the demodulator control signal 12b, and the EX-OR circuit 13b adds mod 2 to the modulated image signal from the image memory 11 and the M-sequence signal, and demodulates the signal. The image signal is input to the S/P converter 14 manually.

Therefore, if the recitation number input to the recitation number setting device 10a is exactly the same during recording and reproduction, the initial value of the M-sequence generator during recording and reproduction will be the same, and the output will be the same. Since the contents of the M-sequence signals are exactly the same, mod2 addition of the EX-OR circuit modulates the modulator 9.
The image signal input to the demodulator 13 matches the image signal output from the demodulator 13. However, 0c singing number setter 10
When the recitation number entered in a is recorded and played back,
If there is even a slight difference, the contents of the output M-sequence signal will change completely, so as long as the recitation numbers do not match, no matter how the stored contents are read out, the demodulation side will reproduce the original image. It is not possible.

Therefore, only a person who knows the code number recorded in the image memory 11, that is, the person who took the image or a person who has obtained permission from the person who took the image, can display the original image recorded in the image memory 11 on a display or output on a printer. can be played on the device.

In the embodiments described above, parallel digital image signals are converted into serial signals and modulated or demodulated, but the present invention can be applied to modulation or demodulation even with parallel signals as they are.

Other embodiments of the present invention are shown in FIGS. 7 and 8. In the embodiments shown in FIGS. 7 and 8, the P/S converter 8 and S/P converter 14 in the first embodiment shown in FIGS. 1 and 3 are removed, and the modulator 9 and demodulator 13
8-bit parallel signals are simultaneously modulated in the image memory 11, and 8-bit parallel signals are written in the image memory 11 in parallel.

FIG. 9 shows the configuration of the modulator 9 in the embodiment shown in FIGS. 7 and 8 (second embodiment). As shown in FIG. 9, the 8-bit output data of the register of the M-sequence generator (XO%X) and the 8-bit parallel image signal are EX-ORed.
Modulation and demodulation can be realized in the same way as in the first embodiment by adding each signal mod 2 using a circuit. In particular, in this embodiment, since parallel processing is performed, not only an S/P converter and a P/S converter are not required compared to the first embodiment, but also the modulator control signal 6b etc. This has the advantage of being easy to operate.

FIGS. 10 and 11 show the configuration of an embodiment of the present invention in which image signals are modulated and demodulated without using pseudo-random numbers such as M-sequence signals.

FIG. 10 shows a circuit configuration of a modification of the modulator 9 of the digital electronic still camera shown in FIG. In this figure, 9c is a signal from the binary converter 10b according to the modulator control signal 6d.
P to convert 0-bit parallel data to serial data
9d is a data selector that switches and outputs either the output of the P/S converter 9C or the output of the P/S converter 8 to the image memory 11 according to the modulator control signal 6d. It is.

Further, FIG. 11 shows a circuit configuration of a modification of the demodulator 10 of the image reproducing apparatus shown in FIG. 3. In FIG. In the figure, 13c is a data selector that switches and outputs the modulated digital image signal read from the image memory 11 to either the S/P converter 13d or the S/P converter 14. The S/P converter 13d converts the serial digital image signal from the data selector 13c into a parallel digital image signal according to the demodulator control signal 12b, and outputs it to the data comparator 13e. In the data comparator 13e, the S/P converter 1
Compare the output signal of 3d and the output of binary converter 10b,
The comparison result is output to the data selector 13c.

Next, the operation of the embodiment of the present invention shown in FIGS. 10 and 11 will be explained. In the configuration shown in FIG. 1O, before storing the digital image signal in the image memory 11, the data selector 9d stores the recitation code data signal from the P/S converter 9c, and then the data selector 9d switches to the P/S. The signal from the S converter 8 is stored in the image memory 11. In the configuration shown in FIG. 11, when reading out the information stored in the image memory 11, the data selector 13c first sends the information from the image memory 11 to the S/P converter 13d, and the S/P converter 13d converts the information. The data comparator 13e compares the obtained 10-bit parallel data with the 10-bit parallel data from the binary converter 1Ob, and if the two data match, the data selector 13c outputs the matching output from the data comparator 13e. is switched to the S/P converter 14 side, and the digital image signal from the image memory 11 is set to be output to the S/P converter 14. Therefore, the data selector 13c switches to the S/P converter 14 side for image reproduction only when the recitation numbers during recording and playback match, so when the recitation numbers do not match, information is read from the image memory 11. The original image cannot be reproduced and displayed.

Note that the code input device is not limited to a keyboard type device fixed to the device, but may also be a card type device in which recited codes are registered in advance. Further, instead of the image memory 11, a floppy disk, a magnetic disk, an optical disk, etc. can be used. Furthermore, the target information (human-powered digital signals) is not necessarily limited to image information from an imaging device such as a camera, but may also include blueprints created on a computer using the CAD (Computer Aided Design) method, or information created using a word processor. It can also be applied to things like textual information.

(Effects of the Invention) As explained above, according to the present invention, if the same number is not input during signal modulation and demodulation, the original signal cannot be demodulated. It becomes possible to protect copyrights, prevent infringement of personal interests due to copying, etc., and prevent copying and reproduction of highly confidential information to ensure the safety and profits of companies, etc. The effect of this can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration of a digital electronic still camera according to the first embodiment of the present invention, FIG. 2 is a block diagram showing the circuit configuration of the code input device and modulator shown in FIG. 1, and FIG. 4 is a block diagram showing the circuit structure of the image reproducing device according to the first embodiment of the present invention; FIG. 4 is a block diagram showing the circuit structure of the code input device and demodulator shown in FIG. 3; FIG. 5 is the modulation diagram shown in FIG. 2. FIG. 6 is a timing chart showing the output timing of the output control signal in the embodiment of FIG. 1, and FIG. FIG. 8 is a block diagram showing the circuit configuration of a still camera; FIG. 8 is a block diagram showing the circuit configuration of an image reproducing device according to the second embodiment of the present invention; FIG. 9 is a block diagram showing an example of the configuration of the modulator shown in FIG. 7. , FIG. 10 is a block diagram showing a modified example of a modulator to which the present invention is applied, and FIG. 11 is a block diagram showing a modified example of a demodulator to which the present invention is applied. DESCRIPTION OF SYMBOLS 1...Subject, 2...Photographing lens, 3...Shutter, 4...Image sensor, 7...A/D converter, 8...P/S converter, 9... Modulator, 9a...M sequence generator, 9b...EX-OR circuit, 9c...P/S converter, 9d...data selector, IO...code input device, tea... Recitation number setter, 10b... Binary converter, 11... Image memory, 13... Demodulator, 13a... M sequence generator, L3b/EX-OR circuit, 13c... Data selector , 13d... S/P converter, 13'e... Data comparator, 14... S/P converter, 15... D/A converter'. rtJ of the first embodiment, block diagram of the translation Figure 2 Figure 1 Reality 7ii! Fig. 4: 7' lock diagram of fi+return device

Claims (1)

[Claims] 1) code input means for encoding a predetermined number to form code information; modulation means for modulating an input digital signal based on the code information; A modulation/demodulation system comprising: demodulation means for demodulating an original digital signal based on information. 2) The modulation/demodulation system according to claim 1, further comprising a number setting means for variably setting the predetermined number. 3) A modulation system comprising: code input means for encoding a predetermined number to form code information; and modulation means for modulating an input digital signal based on the code information. 4) A reproduction system comprising: code input means for encoding a predetermined number to form code information; and demodulation means for demodulating an input digital signal based on the code information.