A method and apparatus for protecting display information

Abstract

This invention relates to a method and apparatus for protecting display information. The method includes: displaying a first target image and a second target image on the same display terminal; controlling the brightness variation of the display terminal when displaying the first target image to a first brightness range, and the brightness variation when displaying the second target image to a second brightness range; controlling the average brightness of the display terminal when displaying the first target image to a first brightness, and the average brightness of the display terminal when displaying the second target image to a second brightness. The technical solution of this invention, by scrambling the target image and displaying it with different brightness levels, and by controlling a synchronous receiving device to receive the target image, makes it impossible for the naked eye or a camera to see or capture the target image to be displayed from the display terminal, thereby improving the security of information display and fundamentally preventing the leakage of display information.

Description

Technical Field

[0001] This invention relates to the field of image display technology, and in particular to a method and apparatus for protecting display information. Background Technology

[0002] Typically, when using various display terminals (such as laptops, desktop monitors, and all-in-one conference machines), users sometimes want important content displayed on the screen to be viewed only by them, preventing unintentional or intentional viewing by bystanders. This is especially important for users with confidentiality requirements. Therefore, there is a need to provide display terminals with display information protection functions to meet these specific user needs.

[0003] To address these needs, privacy protection measures are currently widely used for computer monitors, mobile phone screens, and projectors. This primarily involves adding a privacy film to the display surface, making the screen information visible from the front but not from the sides, preventing others from seeing the screen content. The principle is to control the angle of light, narrowing the viewing angle to approximately 30 degrees. Obviously, this type of privacy protection only prevents information leakage to a certain extent and has significant limitations. Another type of screen capture and traceability technology adds information and identifiers that are difficult for the human eye to recognize to the displayed image. These identifiers correspond uniquely to the electronic device displaying the content. If relevant content is captured and leaked, appropriate equipment can identify from the photograph which device the information was leaked from, facilitating investigation and evidence collection by relevant departments. However, this method can only serve as a supplementary remedial measure and cannot fundamentally prevent information leakage. Summary of the Invention

[0004] Based on the above-mentioned situation of the prior art, the purpose of this embodiment of the invention is to provide a display information protection method and device, which achieves fundamental protection of display information by scrambling the display target image and displaying it with different display brightness.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for protecting display information is provided, the method comprising:

[0006] A first target image and a second target image are displayed on the same display terminal. The first target image is the image to be displayed, and the second target image is an image formed by real-time scrambling of the first target image.

[0007] The brightness change of the display terminal when displaying the first target image is a first brightness range, and the brightness change when displaying the second target image is a second brightness range, wherein the second brightness range is greater than or equal to the first brightness range;

[0008] The average brightness of the display terminal when displaying the first target image is defined as the first brightness, and the average brightness of the display terminal when displaying the second target image is defined as the second brightness. The second brightness is greater than the first brightness, and both the first brightness and the second brightness are within the range of the second brightness.

[0009] Furthermore, the method also includes:

[0010] Set the initial brightness to a preset value;

[0011] The second brightness is controlled to be a value that changes over time.

[0012] Furthermore, the method also includes:

[0013] Set the initial brightness to a preset value;

[0014] The second brightness is controlled to a value that varies with the display area.

[0015] Furthermore, the method also includes:

[0016] The initial brightness is controlled to be a value that changes over time, with a rate of change of t1 over time;

[0017] The second brightness is controlled to be a value that changes over time, with a rate of change of t2.

[0018] Among them, t1 <t2。

[0019] Furthermore, the method also includes:

[0020] The first brightness is controlled to be a value that varies with the display area, and the rate of change with the display area is l1;

[0021] The second brightness is controlled to be a value that varies with the display area, and the rate of change with the display area is l2;

[0022] Among them, l1 <l2。

[0023] Furthermore, the method also includes:

[0024] When the display terminal displays the first target image, the display content of the display terminal is received synchronously;

[0025] When the display terminal displays the second target image, the display content of the receiving display terminal is turned off.

[0026] Furthermore, displaying the first target image and the second target image on the same display terminal includes:

[0027] Simultaneously display a first target image and a second target image on the same display terminal, and display the first target image and the second target image alternately, with odd-numbered rows of pixels displaying the first target image and even-numbered rows of pixels displaying the second target image; or...

[0028] The first target image and the second target image are displayed simultaneously on the same display terminal, and the first target image and the second target image are displayed in alternate columns, with the first target image displayed in odd-numbered columns and the second target image displayed in even-numbered columns.

[0029] Furthermore, displaying the first target image and the second target image on the same display terminal includes:

[0030] The first target image and the second target image are displayed alternately in time.

[0031] According to another aspect of the present invention, a display information protection device is provided, comprising:

[0032] A display control device is used to display a first target image and a second target image on the same display terminal. The first target image is an image to be displayed, and the second target image is an image formed by scrambling the first target image.

[0033] A brightness control device is used to control the brightness change of the display terminal when displaying a first target image to a first brightness range, and the brightness change when displaying a second target image to a second brightness range, wherein the second brightness range is greater than or equal to the first brightness range.

[0034] The brightness control device is further configured to control the average brightness of the display terminal when displaying the first target image to be a first brightness, and the average brightness of the display terminal when displaying the second target image to be a second brightness, wherein the second brightness is greater than the first brightness, and both the first brightness and the second brightness are within the range of the second brightness.

[0035] Furthermore, it also includes a synchronization receiving device, used to synchronously receive the display content of the display terminal when the display terminal displays the first target image, and to turn off receiving the display content of the display terminal when the display terminal displays the second target image.

[0036] In summary, the embodiments of the present invention provide a display information protection method and apparatus. The method includes: displaying a first target image and a second target image on the same display terminal, wherein the first target image is an image to be displayed and the second target image is an image formed by scrambling the first target image; controlling the brightness change of the display terminal when displaying the first target image to a first brightness range, and the brightness change when displaying the second target image to a second brightness range, wherein the second brightness range is greater than or equal to the first brightness range;

[0037] The average brightness of the display terminal when displaying the first target image is set to a first brightness, and the average brightness of the display terminal when displaying the second target image is set to a second brightness. The second brightness is greater than the first brightness, and both the first and second brightness fall within the range of the second brightness. This embodiment of the invention, by scrambling the target image and displaying it at different brightness levels, and by controlling a synchronous receiving device to receive the target image, ensures that the target image to be displayed cannot be seen or captured by the naked eye or a camera from the display terminal, thereby improving the security of information display and fundamentally preventing the leakage of displayed information. Attached Figure Description

[0038] Figure 1 This is a flowchart of the display information protection method provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram showing the first target image and the second target image alternately and cyclically over time. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0041] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of the present invention should have the ordinary meaning understood by those skilled in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in one or more embodiments of the present invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0042] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings. In an embodiment of the present invention, a method for protecting display information is provided. Figure 1 The flowchart of the display information protection method 100 is shown, and the method includes the following steps:

[0043] S102. Display a first target image and a second target image on the same display terminal. The first target image is the image to be displayed, and the second target image is an image formed by real-time scrambling of the first target image based on its characteristics. In this embodiment of the invention, the display terminal can be any one of a mobile phone, laptop computer, desktop monitor, television, or conference all-in-one machine, or other common display terminals. The first target image is the image to be displayed, i.e., the image expected to be displayed. This image can be a text image or a pattern image, and can be a static image or a dynamic image. The second target image is an image formed by scrambling the first target image. For example, the scrambling method involves dividing the first target image into units, shuffling the order of the units, and then rearranging and combining them to generate the second target image.

[0044] According to some embodiments, the first target image is segmented into a matrix of cells. When displayed on a display terminal, each pixel cell in the pixel array of the display terminal corresponds to each element of the matrix. For example, the first target image is represented as matrix HM1:

[0045]

[0046] Where h1l1 represents the content displayed by the first pixel in the first row and first column of the pixel array of the display terminal, h1l2 represents the content displayed by the first pixel in the second column, and so on, for a total of M rows and N columns.

[0047] The content displayed in the second target image can be obtained by translating the content displayed in the first target image. The content displayed in the second target image HM2 can be generated by translating the content displayed in the first target image HM1 vertically between rows, horizontally between columns, or by translating both rows and columns.

[0048] For example, by cyclically shifting the matrix HM1 of the first target image by one row up and down, the matrix HM2 of the generated second target image is:

[0049]

[0050] For example, by cyclically shifting the left and right columns of the matrix HM1 of the first target image by one column, the resulting matrix HM2 of the second target image is:

[0051]

[0052] For example, by cyclically shifting the matrix HM1 of the first target image by one row up and one column down and one column left and right, the matrix HM2 of the generated second target image is:

[0053]

[0054] When performing vertical translation between rows, horizontal translation between columns, and simultaneous translation of rows and columns using the above method, the number of rows and columns to be translated, as well as the number of rows and columns to be translated in the interval, can be determined according to actual needs, and will not be listed here.

[0055] The first target image and the second target image can be displayed on the same display terminal in the following ways:

[0056] A first target image and a second target image are simultaneously displayed on the same display terminal, with the first and second target images displayed alternately, odd-numbered rows displaying the first target image and even-numbered rows displaying the second target image. For example, the first target image matrix HM1 is:

[0057]

[0058] The second target image matrix HM2 is:

[0059]

[0060] At this point, for example, the first row of pixels on the display terminal displays the content of the first row of the matrix HM1:

[0061] [h1l1 h1l2 h1l3 …… h1l N ]

[0062] The second row of pixels on the display terminal shows the content of the second row of the matrix HM2:

[0063] [h1l N h1l1 h1l2 …… h1l N ]

[0064] The third row of pixels in the display terminal shows the contents of the third row of the display matrix HM1:

[0065] [h3l1 h3l2 h3l3 …… h3l N ]

[0066] The fourth row of the display terminal shows the content of the fourth row of the pixel display matrix HM2:

[0067] [h3l N h3l1 h3l2 …… h3l N ]

[0068] This process continues until the contents of both the first and second target images are fully displayed.

[0069] Alternatively, the first and second target images can be displayed in alternating columns, with odd-numbered columns displaying the first target image and even-numbered columns displaying the second target image. The specific display method is the same as the alternating row display described above, and will not be repeated here.

[0070] According to some embodiments, a first target image and a second target image are displayed on the same display terminal, or the first target image and the second target image are displayed alternately and cyclically in time. Figure 2 The diagram illustrates the alternating display of a first target image and a second target image over time, as shown below. Figure 2 As shown in the timing diagram Ts1, both the first target image TX1 and the second target image TX2 are displayed at a frame rate of 40 frames per second. Under normal circumstances, each frame lasts 25ms within one second. When the two images are displayed alternately, each frame of the first target image TX1 is displayed for only 12.5ms, and each frame of the second target image TX2 is also displayed for only 12.5ms, thus creating an alternating display of the two images in time. It can be seen that the frame rates of the first target image TX1 and the second target image TX2 are the same. The frame rates of the first target image TX1 and the second target image TX2 can also be different. Furthermore, to improve the clarity of the corresponding target images, the duration of a single frame can be extended.

[0071] S104. The brightness variation of the display terminal when displaying the first target image is controlled to be a first brightness range, and the brightness variation when displaying the second target image is controlled to be a second brightness range, wherein the second brightness range is greater than or equal to the first brightness range. For example, suppose the display terminal is in a normal mode when displaying the target image normally, and the brightness variation range in the normal mode is the normal brightness range. In the scrambling mode, the brightness variation when displaying the first target image is the first brightness range, and the brightness variation when displaying the second target image is the second brightness range, wherein the second brightness range is greater than or equal to the first brightness range, and both the first and second brightness ranges are greater than the normal brightness range. By expanding the brightness variation range of the display terminal in the scrambling mode, the image displayed in the scrambling mode is less easily distinguishable to the naked eye. For brightness control of the display terminal, computer video signals are typically in RGB format, with each of the three colors occupying 8 bits, for a total of 24 bits. First, the RGB signal format of the pixels in the first target image is converted to YUV (4:4:4) format, where Y is luminance (8 bits) and UV is chrominance (8 bits each), also for a total of 24 bits. The value of Y ranges from 0 to 255. At this time, we have:

[0072] Y=(0.257*R)+(0.504*G)+(0.098*B)+16

[0073] C r =V=(0.439*R)-(0.368*G)-(0.071*B)+128

[0074] C b =U=-(0.148*R)-(0.291*G)+(0.439*B)+128

[0075] S106. The average brightness of the display terminal when displaying the first target image is set to a first brightness, and the average brightness of the display terminal when displaying the second target image is set to a second brightness. The second brightness is greater than the first brightness, and both the first and second brightness are within the range of the second brightness. In this step, the brightness values ​​of the display terminal when displaying the first and second target images are further controlled. The average brightness of the display terminal when displaying the target image can be calculated as follows: Let the original brightness of pixel M(i,j) in the target image (where i,j are the coordinates of the pixel in the image) be Y. M (i, j); while in scrambling mode, the brightness of the corresponding pixel in the target image is adjusted to Y. M (i, j). Similarly, the brightness values ​​of 3×3 points centered at point M can be marked sequentially. Typically, the brightness of a pixel in an image is correlated with the brightness of its surrounding pixels. In this case, the (weighted) average brightness value of a certain area around that point is calculated. It can more accurately reflect the changes in regional brightness.

[0076]

[0077] The average brightness can also be calculated by marking the brightness values ​​of 5×5 points, 7×7 points, or more points centered on point M.

[0078] The control of the first and second brightness levels in this step can be achieved through the following methods:

[0079] S1061. Control the first brightness to a preset value; control the second brightness to a value that changes over time. For example, let the first brightness be k1 and the second brightness be k2, then k1 = K, where K is the preset brightness value, within the range of the first brightness; k2 = g(t), where g(t) is a function that changes with time t, which can be a linear function or a non-linear function. That is, the display brightness when displaying the second target image changes over time, it can become brighter or darker over time, and the rate of change can be a constant or a variable value, and the final range of change should be within the range of the second brightness.

[0080] S1062. Control the first brightness to a preset value; control the second brightness to a value that varies with the display area. For example, let the first brightness be k1 and the second brightness be k2. Then k1 = K, where K is a preset brightness value within the above first brightness range; k2 = f(l), where f(l) is a function that varies with the display area l and can be a linearly varying function or a non-linearly varying function, that is, the display brightness when displaying the second target image varies with the display area. The display area l can be the row or column of the pixel array of the display terminal. When l represents the row of the pixel array, when the display terminal displays the second target image, the display brightness changes sequentially with the number of rows of the pixel array; when l represents the column of the pixel array, when the display terminal displays the second target image, the display brightness changes sequentially with the number of columns of the pixel array. The display area l can also be the divided area after the pixel array of the display terminal divides the display image according to a predetermined rule. For example, areas with similar colors can be divided into one area, or the area that does not change in multiple consecutive frames of a dynamic image can be used as the background area, and the area that changes can be used as the foreground area. After such display area division, when the display terminal displays the second target image, the display brightness changes with different areas.

[0081] S1063. Control the first brightness to a value that varies with time, and the rate of change with time is the first change rate t1; control the second brightness to a value that varies with time, and the rate of change with time is the second change rate t2; where t1 < t2. For example, let the first brightness be k1 and the second brightness be k2. Then k1 = g1(t), k2 = g2(t), and both g1(t) and g(t) are functions that vary with time t. When both g1(t) and g2(t) are linearly varying functions, that is, both the first change rate t1 and the second change rate t2 are constants, and t1 < t2. g1(t) and g2(t) can also both be non-linearly varying functions, or one of them is a linearly varying function and the other is a non-linearly varying function.

[0082] S1064. Control the first brightness as a value that varies with the display area, and the change rate with respect to the display area is the first change rate l1; control the second brightness as a value that varies with the display area, and the change rate with respect to the display area is the second change rate l2; where l1 < l2. For example, let the first brightness be k1 and the second brightness be k2, then k1 = f1(l); k2 = f2(l), and both f1(l) and f2(l) are functions that vary with the display area l. They can be linearly varying functions or non-linearly varying functions, that is, the display brightness when showing the first target image and the second target image varies with the display area. When both are linearly varying functions, l1 < l2. f1(t) and f2(t) can also both be non-linearly varying functions, or one of them is a linearly varying function and the other is a non-linearly varying function. The display area l can be the rows or columns of the pixel array of the display terminal. When l represents the rows of the pixel array, when the display terminal shows the target image, the display brightness changes sequentially with the number of rows of the pixel array; when l represents the columns of the pixel array, when the display terminal shows the target image, the display brightness changes sequentially with the number of columns of the pixel array. The display area l can also be the divided area after the pixel array of the display terminal divides the display image according to a predetermined rule. For example, areas with similar colors can be divided into one area, or the areas that do not change in multiple consecutive frames of a dynamic image can be used as the background area, and the areas that change can be used as the foreground area. After such a display area division, when the display terminal shows the target image, the display brightness changes with different areas.

[0083] The method in this embodiment of the invention further includes: when the display terminal displays a first target image, synchronously receiving the display content of the display terminal; when the display terminal displays a second target image, turning off the reception of the display content of the display terminal. The display image can be received using a synchronous receiving device, such as synchronous glasses. When the first target image is displayed, the two lenses of the synchronous glasses are controlled to open synchronously, at which time the light from the display terminal screen is viewed through the two lenses; when the display terminal displays the second target image, the two lenses of the synchronous glasses are controlled to close synchronously, at which time the light from the display terminal screen is blocked by the two lenses and cannot be viewed. Therefore, only the normal first target image display content can be seen through the synchronous glasses. It can be seen that when the first target image is displayed within its corresponding display time, the first target image, i.e., the normal image, can be observed through the synchronous glasses. However, when the second target image, i.e., the scrambled image, is displayed within its corresponding display time, the scrambling cannot be observed through the synchronous glasses because the control signal sent to the synchronous glasses during the display time of the second target image causes the synchronous glasses to close, preventing the display content of the second target image from being seen. Therefore, when the user wears the synchronous glasses, they only see the first target image, i.e., the normal image. As for shooting equipment or direct observation with the naked eye, since the display terminal shows the first target image and the second target image, that is, the normal image and the scrambled image, the overall image is presented as a messy image. Therefore, a normal image cannot be obtained, which has the effect of preventing shooting and peeping, or in other words, the captured image has no visual value.

[0084] An embodiment of the present invention also provides a display information protection device, comprising:

[0085] A display control device is used to display a first target image and a second target image on the same display terminal. The first target image is an image to be displayed, and the second target image is an image formed by scrambling the first target image. A brightness control device is used to control the brightness change of the display terminal when displaying the first target image to a first brightness range, and the brightness change when displaying the second target image to a second brightness range. The second brightness range is greater than or equal to the first brightness range.

[0086] The brightness control device is further configured to control the average brightness of the display terminal when displaying the first target image to be a first brightness, and the average brightness of the display terminal when displaying the second target image to be a second brightness, wherein the second brightness is greater than the first brightness, and both the first brightness and the second brightness are within the range of the second brightness.

[0087] According to some embodiments, the display control device may include a scrambling image generation device, which is used to generate a scrambled second target image in real time based on the characteristics of the first target image to be displayed.

[0088] It also includes a synchronization receiving device, used to synchronously receive the display content of the display terminal when the display terminal displays the first target image, and to turn off receiving the display content of the display terminal when the display terminal displays the second target image. This synchronization receiving device is, for example, synchronization glasses. The synchronization glasses are wirelessly or wiredly interconnected with the brightness control device. The synchronization glasses receive wireless communication signals from the brightness control device and synchronously control the opening action of the lenses of the synchronization glasses to match the display of the first target image, including time synchronization and frequency adaptation. Preferably, the wireless communication signal is an encrypted and / or interference-resistant direct sequence spread spectrum signal or frequency hopping signal, thereby ensuring that the wireless communication signal can effectively and reliably control the synchronization glasses synchronously, preventing the synchronization glasses from malfunctioning due to interference.

[0089] The specific functions and operations of each module in the above-mentioned display information protection device have been described in detail in the display information protection method of the above embodiments, so their repeated description will be omitted here.

[0090] In summary, the embodiments of the present invention relate to a display information protection method and apparatus. The method includes: displaying a first target image and a second target image on the same display terminal, wherein the first target image is an image to be displayed, and the second target image is an image formed by scrambling the first target image; controlling the brightness variation of the display terminal when displaying the first target image to a first brightness range, and the brightness variation of the display terminal when displaying the second target image to a second brightness range, wherein the second brightness range is greater than or equal to the first brightness range; controlling the average brightness of the display terminal when displaying the first target image to a first brightness, and the average brightness of the display terminal when displaying the second target image to a second brightness, wherein the second brightness is greater than the first brightness, and both the first brightness and the second brightness are within the second brightness range. The technical solution of the embodiments of the present invention, by scrambling the target image and displaying it with different display brightness, and by controlling a synchronous receiving device to receive the target image, makes it impossible for the naked eye or a shooting device to see or capture the target image to be displayed from the display terminal, thereby improving the security of information display and fundamentally preventing the leakage of display information.

[0091] It should be understood that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of this invention, technical features of the above embodiments or different embodiments can also be combined, steps can be implemented in any order, and many other variations exist regarding different aspects of one or more embodiments of the invention as described above, which are not provided in the details for the sake of brevity. The specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A method for protecting display information, characterized in that, The method includes: A first target image and a second target image are displayed on the same display terminal. The first target image is the image to be displayed, and the second target image is an image formed by real-time scrambling of the first target image. The brightness change of the display terminal when displaying the first target image is a first brightness range, and the brightness change when displaying the second target image is a second brightness range, wherein the second brightness range is greater than or equal to the first brightness range; The average brightness of the display terminal when displaying the first target image is defined as the first brightness, and the average brightness of the display terminal when displaying the second target image is defined as the second brightness. The second brightness is greater than the first brightness, and both the first brightness and the second brightness are within the range of the second brightness.

2. The method according to claim 1, characterized in that, The method further includes: Set the initial brightness to the preset value; The second brightness is controlled to be a value that changes over time.

3. The method according to claim 1, characterized in that, The method further includes: Set the initial brightness to a preset value; The second brightness is controlled to a value that varies with the display area.

4. The method according to claim 1, characterized in that, The method further includes: The initial brightness is controlled to be a value that changes over time, with a rate of change of t1 over time; The second brightness is controlled to be a value that changes over time, with a rate of change of t2. Among them, t1 <t2。 5. The method according to claim 1, characterized in that, The method further includes: The first brightness is controlled to be a value that varies with the display area, and the rate of change with the display area is l1; The second brightness is controlled to be a value that varies with the display area, and the rate of change with the display area is l2; Among them, l1 <l2。 6. The method according to any one of claims 2-5, characterized in that, The method further includes: When the display terminal displays the first target image, the display content of the display terminal is received synchronously; When the display terminal displays the second target image, the display content of the receiving display terminal is turned off.

7. The method according to claim 6, characterized in that, The display of the first target image and the second target image on the same display terminal includes: Simultaneously display a first target image and a second target image on the same display terminal, and display the first target image and the second target image alternately, with odd-numbered rows of pixels displaying the first target image and even-numbered rows of pixels displaying the second target image; or... The first target image and the second target image are displayed simultaneously on the same display terminal, and the first target image and the second target image are displayed in alternate columns, with the first target image displayed in odd-numbered columns and the second target image displayed in even-numbered columns.

8. The method according to claim 6, characterized in that, The display of the first target image and the second target image on the same display terminal includes: The first target image and the second target image are displayed alternately in time.

9. A display information protection device, characterized in that, include: A display control device is used to display a first target image and a second target image on the same display terminal. The first target image is an image to be displayed, and the second target image is an image formed by scrambling the first target image. A brightness control device is used to control the brightness change of the display terminal when displaying a first target image to a first brightness range, and the brightness change when displaying a second target image to a second brightness range, wherein the second brightness range is greater than or equal to the first brightness range. The brightness control device is further configured to control the average brightness of the display terminal when displaying the first target image to be a first brightness, and the average brightness of the display terminal when displaying the second target image to be a second brightness, wherein the second brightness is greater than the first brightness, and both the first brightness and the second brightness are within the range of the second brightness.

10. The apparatus according to claim 9, characterized in that, It also includes a synchronization receiving device, used to synchronously receive the display content of the display terminal when the display terminal displays the first target image, and to turn off receiving the display content of the display terminal when the display terminal displays the second target image.

Images