JP5006435B2 - Peeping prevention device or method - Google Patents

Description

  The present invention relates to a voyeurism prevention device, and more particularly, to an obstruction processing using an arbitrary obstruction image.

  For digital information, various research institutions are trying to prevent secret leakage by preventing external storage media such as USB memory from being connected to terminals.

  Conventionally, in an impulse-type display device such as a cathode ray tube, the light emission period is several μs to several tens μs, and the pixels are not always illuminated during the shutter opening time of the camera. Therefore, even when the screen was picked up by the camera, a black belt-like disturbance occurred.

  On the other hand, a hold-type display device such as a liquid crystal monitor emits light in the same period as the frame period. Therefore, if a camera, which is an ultra-small imaging means, is brought in, digital information is displayed on the screen, and if it is photographed, there is a possibility that secret information may be leaked.

  Japanese Patent Application Laid-Open No. H10-228707 superimposes periodic visible light that cannot be recognized by humans on a screen of a movie so that an image displayed on the screen cannot be captured as it is when captured by a camera. Technology is disclosed.

Japanese Patent Laid-Open No. 2003-110967

  However, in Patent Document 1, a disturbing image having a specific periodicity is only superimposed, and any still image, moving image, or the like cannot be used as the disturbing image.

  An object of the present invention is to provide a voyeurism prevention apparatus or method using an arbitrary image.

  (1) A voyeurism prevention device according to the present invention is a voyeurism prevention device for a display image in a hold-type display device, and displays the disturbance image data with respect to time or spatial contrast sensitivity when given arbitrary disturbance image data. In this case, there are provided specific frequency component removing means for removing a frequency component by which a human can recognize the disturbing image data, and superimposing means for superimposing the removed disturbing image on the input image.

  Accordingly, it is possible to provide a voyeurism prevention device in which an interference image is displayed on an imaging device, although it is difficult for a human to recognize it using an arbitrary interference image.

  (2) In the voyeurism prevention apparatus according to the present invention, the specific frequency component removing means is lower than a lower limit setting value at which a human can recognize the disturbing image data when the disturbing image data is displayed with respect to time or spatial contrast sensitivity. An intermediate frequency component that is higher and lower than the upper limit set value is removed. Therefore, it is possible to superimpose an interference image from which an intermediate frequency component that is difficult for humans to recognize is removed.

  (3) In the voyeurism prevention apparatus according to the present invention, the specific frequency component removing unit also removes a high frequency component higher than the intermediate frequency or a low frequency component lower than the intermediate frequency. Therefore, the interference image can be superimposed by a normal high-pass filter or low-pass filter.

  (4) In the voyeurism prevention device according to the present invention, a means for generating disturbing image data and providing it to the specific frequency component removing means, comprising a disturbing image data generating means having the following 1) and 2) Yes. 1) A plurality of disturbing image data generating units that generate disturbing image data when given an argument, and 2) an argument giving unit that gives an argument so that each of the disturbing image data generators generates different disturbing image data. This eliminates the need for a frame memory for storing the disturbing image in order to calculate the time contrast sensitivity.

  (5) In the voyeurism prevention device according to the present invention, each of the disturbing image data generating units is arranged in a row, and has a generating unit that generates the same disturbing image when given the same argument. The arguments given by the argument assigning unit to the generating units are values that increase or decrease sequentially in accordance with the arrangement position. Therefore, it is possible to easily generate a disturbing image for calculating the time contrast sensitivity.

  (6) In the voyeurism prevention apparatus according to the present invention, one argument is given to each of the disturbing image data generators from the argument giving means, and the same argument is given to each of the disturbing image data generators. Depending on the position where the disturbing image data generated in the case is arranged in a row, it is configured differently. Therefore, it is possible to easily generate a disturbing image for calculating the time contrast sensitivity.

  (7) In the voyeurism prevention device according to the present invention, it comprises interference image data storage means for storing interference image data of a plurality of frames, and the specific frequency component removal means uses the interference image data of the plurality of frames, When the disturbing image data is displayed, a frequency component that allows a human to recognize the disturbing image data is removed with respect to time contrast sensitivity. Therefore, in order to calculate the time contrast sensitivity, the disturbing image can be stored and the disturbing image data can be generated.

  (8) In the voyeurism prevention apparatus according to the present invention, the disturbing image data storage means has a number of frame memories capable of storing an image for at least one period of the frequency component of the lower limit set value removed by the specific frequency component removal means. Have Therefore, in order to calculate the time contrast sensitivity, the disturbing image can be stored and the disturbing image data can be generated.

  (9) In the voyeurism prevention device according to the present invention, the disturbing image data generation means that generates the disturbing image data and gives it to the specific frequency component removing means, and includes the following 1) to 4) Means. 1) basic image storage means for storing figures or characters to be displayed as disturbing images as basic images, 2) display position determining means for randomly determining display positions of the basic images, 3) display positions of the basic images and the basics When an image is given, a plurality of image generators for generating an image in which the basic image is displayed at the display position, a column direction arrangement image generator arranged in a column direction, and 4) for the plurality of image generators Delay means for providing position information delayed by one frame to the disturbing image generating means. Therefore, it is possible to generate a disturbing image in which the basic image is displayed by changing the position as appropriate.

  (10) A voyeurism prevention device according to the present invention is a disturbing image data generating means for generating disturbing image data of a partial area of one frame and giving it to the intermediate frequency component removing means, and 1) one of one frame A plurality of image generators that generate disturbance image data for a partial area, a column direction arrangement image generator arranged in a column direction, 2) disturbance image generation means for outputting a plurality of disturbance images from the plurality of image generators, 3 ) Interfering image data generating means having delay means for providing position information delayed by one frame to the disturbing image generating means for the column direction arranged image generators arranged in the column direction. Therefore, a disturbing image can be given only for a partial region.

  (11) The voyeurism prevention device according to the present invention is a means for performing a masking reverse characteristic process on the removed disturbance image output from the specific frequency component removal means, and 1) a threshold value storage for storing a threshold value Means, 2) masking inverse characteristic selection having attenuation means for attenuating the dynamic range of the disturbing image after the removal when the differential value of contrast is smaller than the threshold value in relation to adjacent pixels for the input image Removal means are provided. Therefore, it is possible to more reliably prevent the disturbing image from being recognized by human eyes.

  In this specification, “temporal contrast sensitivity function” refers to temporal contrast sensitivity function, “spatial contrast sensitivity function” refers to spatial contrast sensitivity function, and “spatiotemporal contrast sensitivity function” refers to spatial contrast sensitivity and It refers to both contrast sensitivity functions of time contrast sensitivity.

  For example, in the embodiment illustrated in FIG. 2, the “interfering image data generating unit” corresponds to the timing generation unit 22 and the interfering image generators 23a to 23n. In the embodiment shown in FIG. 2, the “intermediate frequency component removing unit” corresponds to the inverse filter 21 having contrast sensitivity characteristics.

   Further, “removing frequency components that allow humans to recognize the disturbing image data” means removing at least frequency components that can be recognized by humans.

  In the following embodiment, as the “column direction arrangement”, the logo image generators 35a to 35n and the disturbing image area generators 55a to 55n are arranged in one row as shown in FIGS. It only has to be functionally arranged in a permutation.

3 is a functional block diagram of the voyeurism prevention device 1. FIG. 2 is a detailed block diagram of the voyeurism prevention device 1. FIG. It is a figure which shows other embodiment. It is a figure which shows other embodiment. It is a figure which shows a masking characteristic. It is a figure which shows a masking characteristic.

  Embodiments of the present invention will be described below with reference to the drawings.

(1. First embodiment)
With reference to FIG. 1, an outline of a voyeurism prevention apparatus 1 according to the present invention will be described. The voyeurism prevention device 1 is a voyeurism prevention device for a display image in a hold type display device, and includes a disturbing image data generation means 3, an intermediate frequency component removal means 5, and a superimposition means 7.

  The disturbing image data generating unit 3 includes a plurality of disturbing image data generating units 13a to 13n and an argument providing unit 15. When an argument is given, the disturbing image data generation units 13a to 13n generate disturbing image data corresponding to the given argument. The argument giving unit 15 gives an argument so that the respective disturbing image data generating units 13a to 13n generate different disturbing image data.

  When the disturbing image data is given from the disturbing image data generating units 13a to 13n, the intermediate frequency component removing unit 5 is arranged so that when the disturbing image data is displayed, the spatio-temporal contrast is prevented so that humans cannot recognize the disturbing image data. Regarding the sensitivity, a frequency component higher than the lower limit set value and lower than the upper limit set value is removed.

  The superimposing means 7 superimposes the interference image after the removal on the input image. The display means 11 displays the input image on which the interference image from which the intermediate frequency is removed is superimposed. As a result, voyeurism prevention processing can be performed using a desired disturbing image.

  FIG. 2 shows a detailed block diagram of the voyeurism prevention device 1. This embodiment includes a timing generator 22, interference image generators 23a to 23n, a contrast sensitivity inverse filter 21, and an adder 31.

  In the present embodiment, pseudo random generators are used as the interference image generators 23a to 23n. The pseudo-random generator is a random generator in which a combination of an argument and an internal state has a one-to-one relationship with an output value, that is, outputs the same combination of random numbers to the same argument. In the present embodiment, the Mersenne Twister (MT) method is adopted as the pseudo-random generator, but it is not limited to this. The output of the pseudo-random function is usually a uniform distribution, but the present invention is not limited to this and may be a non-uniform distribution including a Gaussian distribution.

  The timing generator 22 gives different arguments to the disturbing image generators 23a to 23n. In this case, an argument “t” is input to the interference image generator 23a, an argument “t-1” is input to the interference image generator 23b, an argument “t-2” is input to the interference image generator 23c, and so on. Give "t- (n-1)". This gives different arguments to each disturbing image generator.

  The plurality of interference image generators 23a to 23n are employed for the following reason. In order to remove the intermediate frequency component in the time contrast sensitivity, the frequency component of the lower limit value is required for at least one period. It is conceivable to hold these in a frame memory. However, if the necessary number of frame memories and their control circuits are provided, the manufacturing cost increases accordingly. Therefore, in the present embodiment, the disturbing image is dynamically generated, thereby making the frame memory unnecessary.

  The inverse filter 21 having contrast sensitivity characteristics will be described. In the present embodiment, the intermediate frequency component is temporally removed by the temporal CSF inverse characteristic filter, and then the intermediate frequency component is spatially removed by the spatial CSF inverse characteristic filter.

  Processing by a spatial filter after the temporal filter eliminates the need for an extra frame memory.

  However, the present invention is not limited to this and can be removed as a three-dimensional filter. These are premised on the implementation as a linear filter, but may be non-linear for more visual fidelity.

  In this embodiment, a BEF filter is employed as the temporal CSF inverse characteristic filter and the spatial CSF inverse characteristic filter, and the cut-off frequency is 3 Hz to 50 Hz for the former and 2 cycle / deg to 7 cycle / deg for the latter. In this way, by cutting the intermediate frequency component, a component that can be recognized by humans is removed from the disturbing image. In particular, the presence of the low frequency component has the advantage of becoming more difficult to understand.

  The cut-off frequency is not strictly limited to this. This is because even if it is somewhat narrow, it cannot be reliably recognized by the human eye, and particularly when the temporal and spatial CSF inverse characteristic filters are used in combination, it is more difficult for the human eye to recognize.

  In the present embodiment, the cut-off frequency of the temporal CSF inverse characteristic filter is 3 Hz to 50 Hz. However, in order to make it less visible to the human eye, it is set to 5 Hz to 40 Hz. 20Hz should be used. In addition, the cutoff frequency of the spatial CSF inverse characteristic filter was set to 2 cycles / deg to 7 cycles / deg, but in order to make it more difficult for human eyes to see, it was set to 1 cycle / deg to 20 cycles / deg. May be cut at 30 cycles / deg or less. In the CSF inverse characteristic filter, it may be difficult to set the upper limit of the cutoff frequency depending on the viewing distance and / or the pixel density. In that case, only the lower limit may be set.

  The interference image after removal of the intermediate frequency band provided from the contrast sensitivity characteristic inverse filter 21 is superimposed on the input image data by the adder 31 (see FIG. 2). The superimposed image is displayed on the LCD panel 27. In the displayed image, an image in which the interfering image after removal of the intermediate frequency band is superimposed is displayed, so it cannot be recognized by the human eye, but when it is displayed on a monitor etc. after shooting with a camera , You can capture the disturbing image.

  In the present embodiment, the dynamic pseudo-random function can be realized with a relatively small-scale logic, and the manufacturing cost can be reduced as compared with a frame memory and its control circuit. In addition, an interference image corresponding to a desired frame number can be generated by using a frame number as an input argument as shown below.

  In this way, it is possible to superimpose a disturbing image that is hardly recognizable by humans by using an arbitrary disturbing image generated with a pseudo random number, instead of using a disturbing image having only a specific frequency component.

  The disturbing image generators 23a to 23n may be time-shared to generate a disturbing image. As a result, the number of disturbing image generators can be reduced.

(2. Second Embodiment)
In the above embodiment, a disturbing image generated by a pseudo-random number is used as the disturbing image. However, as an arbitrary image, a logo image in which a predetermined character is converted into a logo is stored, and the display position of the logo image is randomly selected. You may make it change and display.

  FIG. 3 shows a configuration when a logo image is used as an interference image. The logo image memory 34 stores a logo desired to be displayed. The logo position generation part 41 determines a display position at random. The logo image generators 35a to 36n generate a logo image in which the logo image memory 34 is displayed at the display position given from the logo position generator 41. Here, the same position information is not given to the logo image generators 35a to 36n. That is, the delay devices 36a to 36n-1 are connected in series, and the logo image generators are connected between the delay devices. As a result, each of the delay devices 36a to 36n-1 gives a display position one timing earlier to the connected logo image generator. Thereby, the logo image which changed the position of the logo image to insert can be generated. The processing after the inverse filter 21 of contrast sensitivity characteristics is the same.

  In FIG. 3, only the position information to be displayed is transferred, but the size of the logo and the number of copies may be changed. In that case, such information may be generated and transferred in the same manner as the position information.

(3. Third embodiment)
In the second embodiment, since the logo image requires memory access, in order to increase the number of parallel images, the logo image becomes complicated and the manufacturing cost increases. Further, even when a pseudo-random image is employed, calculation processing for one frame is required. Therefore, the disturbing image to be generated may be a part of one frame.

  FIG. 4 shows an embodiment in which only the area specifying information is used as the data to be given to the inverse filter 21 having the contrast sensitivity characteristic without using the actual disturbing image. That is, permutation-connected disturbing image area generators 55a to 55n determine disturbing image area specifying information for specifying the disturbing image area based on the data generated by the timing generator 51. Here, the same value is not given to the disturbing image area generators 55a to 55n. As shown in FIG. 4, delay devices 56a to 56n-1 are connected in series, and each disturbing image area generator is connected between the delay devices. As a result, each of the delay units 56a to 56n-1 provides data one timing earlier to the connected disturbing image area generator. Thereby, different interference image area specific information can be generated.

  Such interference image area specifying information is given to the inverse filter 21 having contrast sensitivity characteristics. The contrast sensitivity characteristic inverse filter 21 outputs an attenuation value in consideration of the visual inverse characteristic of the disturbing image region. By multiplying this attenuation value and the disturbance image given from the disturbance image generator 58, a final disturbance image to be superimposed on the input image can be generated.

  In the present embodiment, the attenuation value is obtained by the inverse filter 21 having the contrast sensitivity characteristic for the pixel of the generated area specifying information. Thereafter, since the data from the interference image generator is multiplied, a frame memory for processing is not required even when a disturbance image of a moving image is used.

  The data after the interference image generator is applied to the attenuation value for the pixel of the generated area specifying information may be given to the inverse filter 21 having the contrast sensitivity characteristic.

  Further, the output of the inverse filter 21 having the contrast sensitivity characteristic and the input image may be added without the interference image generator 48 shown in FIG. As a result, the input image corresponding to the region of the disturbing area that is randomly generated can be processed by regarding it as the disturbing image region. Thereby, even if there is no logo image, a partial blurred image can be displayed. For example, if the shape of the disturbing area is changed by a monitor that displays the shape, the captured monitor can be specified.

  In this way, an attenuation value that takes into account the visual inverse characteristic of each disturbing image area output from the inverse filter 21 having the contrast sensitivity characteristic can be grasped as the disturbing image.

(4. Other embodiments)
Note that, in the second and third embodiments, as shown in FIG. 5, it may be configured using one disturbing image generator 23 and a plurality of frame memories 61 a to 61 n.

  Further, based on the input image, the dynamic range of the disturbing image may be attenuated by a masking inverse characteristic filter. The input image is divided into a plurality of areas, and the contrast ratio with adjacent pixels in each area is obtained. If the obtained contrast ratio is lower than a preset threshold value, the dynamic range of the disturbing image is attenuated. After such data processing, it is superimposed on the input image. Here, the masking inverse characteristic filter is a general shrinkage filter that attenuates the dynamic range of the disturbing image if the contrast (differential value) of the input image is lower than a certain threshold value.

  When the contrast ratio of a pixel at a certain position is high, humans have a characteristic that the difference is difficult to perceive even if there is a pixel with a low contrast ratio around the pixel (see FIG. 6). In FIG. 6, the horizontal axis represents the mask contrast and the vertical axis represents the target contrast ratio. As shown in the graph, up to a certain value, the contrast ratio of the object is almost constant even when the mask contrast increases. However, when the mask contrast is exceeded, the contrast ratio of the object increases. By using such characteristics, it is possible to make it difficult to recognize the disturbing image according to the contrast ratio of each region of the input image.

  Since the contrast displayed on the monitor and the contrast ratio projected on the photograph are different, the masking effect is not always maintained even in the photograph, so this method is effective.

  In addition, when the contrast ratio of each area | region of an input image is higher than the preset threshold value, you may make it amplify the dynamic range of a disturbance image.

  A Laplacian filter may be used for measuring the contrast of the input image.

  A modification of the inverse filter 21 having the contrast sensitivity characteristic shown in FIG. 2 will be described. In the above embodiment, the intermediate frequency component is removed. However, only a high frequency component higher or lower than the intermediate frequency component may be passed. For example, as a temporal CSF inverse characteristic filter, the cut-off frequency may be about 50 Hz. As such a high-pass filter, for example, a Butterworth type one-dimensional HPF can be adopted. Further, the cut-off frequency may be set to 30 cycles / deg as a spatial CSF inverse characteristic filter. For example, a Butterworth type two-dimensional HPF can be adopted.

  In this way, by using a filter that allows only low frequency components or high frequency components to pass through in addition to the intermediate frequency band, it is possible to superimpose an interference image of an arbitrary image with a filter having a simple configuration.

In the above embodiment, the interference image and the input image data are luminance values. Therefore, the inverse image is not corrected and the disturbing image is superimposed on the input image. However, it may be data capable of calculating a luminance value, for example, an RGB value. Further, when the disturbing image and the input image data cannot be expressed by the luminance value unit cd / m ² and the primary relational expression, the relation may be corrected by the conversion table. For example, inverse gamma correction.

  In the above embodiment, the case where the luminance CSF is used has been described. However, the color difference CSF may be used so that it cannot be recognized by human eyes.

  Furthermore, if it is not a liquid crystal monitor but a hold type monitor such as an organic EL, it can be similarly applied to a monitor that irradiates linearly polarized light from the display surface.

  In the present embodiment, digital data is superimposed using an adder, but may be multiplied.

  Moreover, it can also be comprised as a display apparatus containing the voyeurism prevention apparatus of this embodiment.

  In the present embodiment, as shown in FIG. 2, a plurality of disturbing image data generators 23a to 23n are arranged in a row, and as arguments given to the disturbing image data generators 23a to 23n, depending on their arrangement positions. The values were increased or decreased sequentially. However, any configuration may be used as long as each of the disturbing image data generators 23a to 23n generates different disturbing image data. For example, an argument given to a plurality of disturbing image data generators is 1. In addition, the interference image data generators may be configured to be shifted in accordance with the positions sequentially arranged in a row. For example, in the disturbing image data generator, the first disturbing image data generator generates +0 according to the given argument, the second disturbing image data generator generates +1, and the third disturbing image data is generated. The unit may add the value +2.

  The voyeurism prevention device disclosed in this specification may be configured as a disturbing image generation device for the voyeurism prevention device.

(5. Disclosure as other inventions)
A part of the apparatus or method disclosed in this specification can be understood as the apparatus or method described below.

A device for preventing voyeurism of a display image in a hold type display device,
Threshold storage means for storing the threshold;
Attenuating means for attenuating the dynamic range of the disturbing image after the removal when the differential value of contrast is smaller than the threshold value in relation to the adjacent pixels for the input image,
Superimposing means for superimposing the attenuated disturbance image data on an input image;
A voyeurism prevention device characterized by comprising:

Claims (15)

A device for preventing voyeurism of a display image in a hold type display device,
Given arbitrary disturbing image data, with regard to temporal or spatial contrast sensitivity, specific frequency component removing means for removing a frequency component that allows humans to recognize the disturbing image data when the disturbing image data is displayed,
Superimposing means for superimposing the interference image after the removal on the input image;
A voyeurism prevention device characterized by comprising: The anti-voyeurism device according to claim 1,
The specific frequency component removing means has a frequency higher than a lower limit setting value at which a human can recognize the disturbing image data when the disturbing image data is displayed with respect to time or spatial contrast sensitivity, and at a frequency lower than the upper limit setting value. Removing certain intermediate frequency components,
An anti-voyeurism device characterized by The anti-voyeurism device according to claim 2 ,
The specific frequency component removing means removes a high frequency component higher than the intermediate frequency or a low frequency component lower than the intermediate frequency;
An anti-voyeurism device characterized by In the voyeurism prevention device according to any one of claims 1 to 3,
Means for generating disturbing image data and giving the specific frequency component removing means, the following 1), disturbing image data generating means having 2),
1) A plurality of disturbing image data generating units for generating disturbing image data when given an argument,
2) an argument giving unit for giving an argument so that each of the disturbing image data generators generates different disturbing image data;
A voyeurism prevention device characterized by comprising: The anti-voyeurism device according to claim 4,
Each of the disturbing image data generating units is arranged in a row and has a generating unit that generates the same disturbing image when the same argument is given,
The argument given by the argument assigning unit to each of the generating units is a value that gradually increases or decreases depending on the arrangement position thereof,
An anti-voyeurism device characterized by The anti-voyeurism device according to claim 4,
The argument given from the argument giving unit to each disturbing image data generator is one,
Each of the disturbing image data generators is configured to be different depending on the position where the disturbing image data to be generated when the same argument is given is arranged in a row,
An anti-voyeurism device characterized by In the voyeurism prevention apparatus in any one of Claims 1-3,
Interference image data storage means for storing interference image data of a plurality of frames is provided,
The specific frequency component removing means removes a frequency component that allows a human to recognize the disturbing image data when the disturbing image data is displayed using the plurality of frames of disturbing image data in terms of time contrast sensitivity.
An anti-voyeurism device characterized by The voyeurism prevention device according to claim 7,
The interference image data storage means has a number of frame memories capable of storing an image for at least one period of the lower limit set value frequency component removed by the specific frequency component removal means;
An anti-voyeurism device characterized by The anti-voyeurism device according to claim 1,
Interference image data generating means for generating interference image data and giving it to the specific frequency component removing means, the interference image data generating means having the following 1) to 4):
1) Basic image storage means for storing figures or characters to be displayed as disturbing images as basic images,
2) display position determining means for randomly determining the display position of the basic image;
3) Given the display position of the basic image and the basic image, a plurality of image generators for generating an image in which the basic image is displayed at the display position, a column direction arrangement image generator arranged in the column direction,
4) Delay means for providing position information delayed by one frame for each of the plurality of image generators to the disturbing image generation means,
A voyeurism prevention device characterized by comprising: The anti-voyeurism device according to claim 1,
A disturbing image data generating means that generates disturbing image data of a partial area of one frame and gives it to the specific frequency component removing means , the disturbing image data generating means having the following 1) to 3):
1) A plurality of image generators for generating disturbing image data for a partial area of one frame, a column direction arrangement image generator arranged in a column direction,
2) interference image generation means for outputting a plurality of interference images from the plurality of image generators,
3) delay means for providing the disturbing image generating means with position information delayed by one frame for the image generators arranged in the column direction;
A voyeurism prevention device characterized by comprising: In the voyeurism prevention device according to any one of claims 1 to 10,
Masking reverse characteristic selection removing means for performing masking reverse characteristic processing on the interference image after removal output from the specific frequency component removing means,
Having the following:
a) Threshold storage means for storing a threshold;
b) Attenuating means for attenuating the dynamic range of the disturbing image after the removal when the differential value of contrast is smaller than the threshold value in relation to the adjacent pixels for the input image,
An anti-voyeurism device characterized by A device for preventing voyeurism of a display image in a hold type display device,
When arbitrary disturbing image data is given, the temporal or spatial contrast sensitivity is higher than a lower limit setting value at which a human can recognize the disturbing image data when the disturbing image data is displayed, and is higher than the upper limit setting value. Specific frequency component removing means for obtaining a disturbing image in which a high frequency component higher than the intermediate frequency and a low frequency component lower than the intermediate frequency are left from the disturbing image data by removing an intermediate frequency component which is a low frequency;
Superimposing means for superimposing the disturbing image data leaving the high frequency component and the low frequency component on the input image;
Having
An anti-voyeurism device characterized by   A hold-type display device comprising the anti-voyeurism device according to any one of claims 1 to 12. A voyeurism prevention device according to claim 9 or claim 10,
The superimposing means includes an adder or a multiplier, and interference image data from which a frequency component that allows a human to recognize the interference image data when the interference image data is displayed is removed by the adder or multiplier. If, by superimposing said input image,
And further comprising display means for displaying the superimposed data.
A display device with anti-voyeurism features. A device for preventing voyeurism of a display image in a hold type display device,
One image generator for generating a partial interfering image corresponding to a partial area of one frame;
Display position determining means for determining the display position of the partial disturbing image so that the disturbing image is displayed at a position delayed by one frame between a plurality of frames;
Attenuation data calculation means for calculating attenuation data related to temporal contrast sensitivity for each pixel in the area of the partial disturbance image data when the partial disturbance image data is displayed at the determined display position;
A post-attenuation disturbing image data calculation means for calculating post-attenuation disturbing image data for obtaining a disturbing image in which each pixel value of the partial disturbing image given from the image generator is attenuated by the attenuation data of each frame;
Comprising superimposing means for superimposing the input image;
The attenuation data of each frame is higher than the lower limit setting value at which the human can recognize the partial disturbance image when the partial disturbance image is displayed, and lower than the upper limit setting value. By removing an intermediate frequency component that is a frequency, the interference image data is a data that can obtain an interference image in which a high frequency component higher than the intermediate frequency and a low frequency component lower than the intermediate frequency are left.
An anti-voyeurism device characterized by

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