Watermark embedding method and display device

Abstract

The present disclosure provides a watermark embedding method and a display device. The watermark embedding method includes the following steps. A processing circuit multiplies a time series signal and a preset data signal to generate a watermark signal. In a first period of each of a plurality of periods and a second period adjacent to the first period, the phases of the time series signal are opposite and the average values of the preset data signal are the same, so that the sum of the watermark signal in the first period and the second period is zero. The processing circuit embeds the watermark signal in a first partition dimming signal to generate a second partition dimming signal, so that the second partition dimming signal carries a watermark message. A backlight module controls the brightness of a plurality of dimming regions according to the second partition dimming signal carrying the watermark message.

Description

TECHNICAL FIELD

[0001] The present application relates to a watermark embedding method, in particular, to a watermark embedding method and display device associated with human visual perception. BACKGROUND

[0002] In today's life, with the increasing dependence on display and the improvement of the display, users often need to use the display to present the presentation, data, picture, image. However, in such a case, if the picture or image presented by the display does not indicate its source, and is taken and randomly spread, it is usually difficult to trace its source. Therefore, how to improve the situation that the displayed data is outflowed by the camera and the source cannot be traced is an important issue in the art. SUMMARY

[0003] The present disclosure provides a watermark embedding method, comprising the following steps. A first partition dimming signal is generated by a processing circuit according to an input image. A time series data and a preset gray scale scheme are multiplied to generate a gray scale message of a floating watermark signal by the processing circuit. Wherein in a first period of each of a plurality of consecutive periods and a second period adjacent to the first period, the phase of the time series data is opposite and the average value of the preset gray scale scheme is the same, so that the total of the gray scale message of the floating watermark signal is zero. The floating watermark signal is embedded in the first partition dimming signal by the processing circuit to generate a second partition dimming signal, so that the second partition dimming signal carries the floating watermark information. The brightness of a plurality of dimming regions is controlled by a backlight module according to the second partition dimming signal carrying the floating watermark information.

[0004] The present disclosure provides a display device. The display device comprises a processing circuit and a storage device. The storage device is electrically coupled to the processing circuit. The storage device is used to store instructions or data for the processing circuit to execute. The processing circuit is used to perform the following steps. A time series data and a preset gray scale scheme are multiplied to generate a gray scale message of a floating watermark signal, wherein in a first period of each of a plurality of periods and a second period adjacent to the first period, the phase of the time series data is opposite and the average value of the preset data signal is the same, so that the sum of the floating watermark signal in the first period and the second period is zero. The floating watermark signal is embedded in the first partition dimming signal by the processing circuit to generate a second partition dimming signal. The brightness of a plurality of dimming regions is controlled by a backlight module according to the second partition dimming signal.

[0005] In summary, the background brightness presented by the backlight module will include the periodically displayed high dynamic floating watermark state image of the floating watermark, so that the image displayed by the display device will also include the floating watermark pattern switched by the backlight module at high frequency at different gray scales, thereby improving the probability that the camera captured picture includes recognizable floating watermark pattern information. And under the high update rate of the backlight module, the periodically presented floating watermark in the bright and dark states cannot be perceived by the human eye. BRIEF DESCRIPTION OF DRAWINGS

[0006] In order to make the above and other objects, features, advantages and embodiments of the present disclosure more comprehensible, the following will explain the drawings in brief:

[0007] Figure 1 Schematic diagrams of a display device and an electronic device according to some embodiments of the present disclosure.

[0008] Figure 2 Flowchart of a watermark embedding method according to some embodiments of the present disclosure.

[0009] Figure 3 Schematic diagrams of a preset gray scale scheme, time series data, and gray scale information of a watermark signal according to some embodiments of the present disclosure.

[0010] Figure 4 Gray scale information of a watermark signal, gray scale information of a first dimming signal, gray scale information of a second dimming signal, and the second dimming signal according to some embodiments of the present disclosure.

[0011] Figure 5A And Figure 5B Schematic diagrams of gray scale data of a second dimming signal in a watermark region and a non-watermark region according to some embodiments of the present disclosure.

[0012] Figure 6 Schematic diagrams of gray scale information of a watermark signal and exposure time of a camera according to some embodiments of the present disclosure.

[0013] Figure 7 Schematic diagrams of a display device and an electronic device according to some embodiments of the present disclosure.

[0014] Figure 8 Schematic diagrams of a low dynamic watermark signal and a watermark signal according to some embodiments of the present disclosure.

[0015] Figure 9 Schematic diagrams of a frame of an input image, a frame of a display image, and a frame of human visual perception according to some embodiments of the present disclosure.

[0016] Figure 10A And Figure 10B Schematic diagrams of a frame of a display device according to some embodiments of the present disclosure.

[0017] Figure 11Fig. 1 shows a schematic diagram of a preset gray scale scheme, time series data, and a gray scale message of a watermark signal according to some embodiments of the present disclosure.

[0018] Figure 12 Fig. 2 shows a schematic diagram of a preset gray scale scheme, time series data, and a gray scale message of a watermark signal according to some embodiments of the present disclosure.

[0019]

Symbol Description

[0020] In order to make the above and other objects, features, advantages and embodiments of the present disclosure more comprehensible, the following will further describe the present disclosure with reference to the drawings in which:

[0021] 11-16, 21-26: output data

[0022] 100: display device

[0023] 110: processing circuit

[0024] 120: backlight module

[0025] 130: storage device

[0026] 200: watermark embedding method

[0027] 910, 921, 922, 1010, 1020: picture

[0028] HUMV: picture

[0029] DEC: electronic device

[0030] GPU: graphics processor

[0031] VIN: input image

[0032] VOUT: output image

[0033] SDIM2: second partition dimming signal

[0034] S205, S210-S230: step

[0035] PGP, PGPa, PGPb, PGPc: preset gray scale scheme

[0036] TSD, TSDa, TSDb, TSDc: time series data

[0037] IGRAa, IGRAb, IGRAc, IGRAL: gray scale message

[0038] P1H, P2H, P3H: first period

[0039] P1L, P2L, P3L: second period

[0040] C1, C2, C3: cycle

[0041] Pa1-Pa6, Pb1-Pb6, Pc1-Pc6: data scheme

[0042] a11-a13, a21-a23, a31-a33, a41-a43: gray scale value

[0043] b11-b12, b21-b24, b31-b32, b41-b44: gray scale value

[0044] c11-c14, c21-c22, c31-c34, c41-c42: gray scale value

[0045] GL1, GL2W, GL2W: gray scale data DETAILED DESCRIPTION

[0046] The following embodiments will be described in detail with reference to the accompanying drawings, but the embodiments provided are not intended to limit the scope encompassed by the present disclosure, and the description of the structure and operation is not intended to limit the execution order thereof, and any structure recombined by elements, the device generated having equal efficacy, is encompassed by the scope of the present disclosure. In addition, the drawings are only for illustration purposes and are not drawn to scale. For ease of understanding, the same elements or similar elements will be described with the same reference numerals in the following description.

[0047] The terms used in the entire specification and claims, unless otherwise specifically noted, generally have the ordinary meaning as each term is used in the art, in the context of the disclosure, and in the context of the special context.

[0048] In addition, the terms "comprise", "include", "have", "contain", and the like used herein are open terms, i.e., meaning "including, but not limited to". In addition, "and / or" used herein includes any one of the relevant listed items or more than one of them.

[0049] In this document, when an element is referred to as being "coupled" or "connected" to another element, it can mean that the "electrically coupled" or "electrically connected". "Coupled" or "connected" can also be used to indicate that two or more elements are operatively coupled, or interact with each other. In addition, although the terms "first", "second", and the like are used herein to describe different elements or operations, the terms are only used to distinguish the elements or operations described by the same technical terms.

[0050] Please refer to Figure 1 , Figure 1This is a schematic diagram illustrating a display device 100 and an electronic device 130 according to some embodiments of this disclosure. In some embodiments, the display device 100 may be implemented as a display. In other embodiments, the display device 100 may be implemented as a screen of a computer, tablet, or mobile phone, and its associated elements, components, circuits, or modules. Therefore, this application is not limited thereto.

[0051] like Figure 1 As shown, the display device 100 includes a processing circuit 110, a storage device 130, and a backlight module 120. In some embodiments, the processing circuit 110 may be a central processing unit, a microprocessor, a graphics processor, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or other hardware devices suitable for retrieving or executing instructions stored in memory.

[0052] Storage device 130 may be implemented as an electrical, magnetic, optical memory device or other memory for storing instructions or data. In some embodiments, storage device 130 may be implemented as volatile or non-volatile memory. In some embodiments, storage device 130 may be implemented as random access memory (RAM), dynamic random access memory (DRAM), magnetoresistive random access memory (MRAM), phase-change random access memory (PCRAM) or other memory.

[0053] In some embodiments, the backlight module 120 is used to provide sufficient brightness and uniform light source for the display device 100 to display images. In some embodiments, the backlight module 120 may be implemented by a backlight module that supports local dynamic dimming. In some embodiments, the backlight module 120 has 288, 1024 or other numbers of dimming areas. Therefore, this application is not limited thereto.

[0054] In some embodiments, the display device 100 receives the input image VIN from a graphic processing unit GPU of an electronic device DEC. The processing circuit 110 calculates and generates the first partition dimming signal of the backlight module 120 according to the input image VIN, and generates the gray scale data of the watermark signal according to the time series data TSD and the preset gray scale scheme PGP, so as to embed the gray scale data of the watermark signal into the first partition dimming signal, thereby generating the second partition diming signal SDIM2 with the watermark information, so that the backlight module 120 controls the luminance of the plurality of dimming regions according to the second partition dimming signal SDIM2.

[0055] Please refer to Figures 1 to 6 , Figure 2 The flowchart of the watermark embedding method 200 according to some embodiments of the present disclosure is shown. Figure 3 The schematic diagram of the preset gray scale scheme PGP a, the time series data TSD a, and the gray scale information IGRA a of the watermark signal according to some embodiments of the present disclosure is shown. Figure 4 The gray scale information IGRA a of the watermark signal, the gray scale data GL1 of the first dimming signal, the gray scale data GL2W and GL2W0 of the second dimming signal, and the second partition dimming signal SDIM2 according to some embodiments of the present disclosure are shown. Figure 5A and Figure 5B The schematic diagram of the gray scale data GL2W and GL2W0 of the second dimming signal in the watermark region and the non-watermark region according to some embodiments of the present disclosure is shown. Figure 6 The schematic diagram of the gray scale information IGRA a of the watermark signal and the exposure time of the camera according to some embodiments of the present disclosure is shown.

[0056] As Figure 2 shown, the watermark embedding method 200 includes steps S205, S210-S230. In step S205, the processing circuit 110 generates the first partition dimming signal according to the input image VIN. Specifically, the processing circuit 110 receives the input image VIN from the graphic processing unit GPU. In some embodiments, the processing circuit 110 generates the partition dimming signal according to the adjacent frame of the input image VIN, and the backlight module 120 performs dynamic regional dimming according to the partition dimming signal to enhance the bright-dark contrast of the display image.

[0057] In step S210, the processing circuit 110 multiplies the time series data TSD a and the preset gray scale scheme PGP a to generate the gray scale information IGRA a of the watermark signal. In some embodiments, one period (e.g., period C1) of the time series data TSD a includes two periods (e.g., first period P1H and second period P1L).

[0058] In some embodiments, in the first period P1H, the time series data TSDa is in positive phase (with a value of "+1"), and the preset gray scale scheme PGPa multiplied by +1 is in the positive value domain. The gray scale information IGRAa of the watermark signal is set to be in the relatively bright state, and thus the first period P1H can be understood as the watermark bright state period.

[0059] On the other hand, in the second period P1L, the time series data TSDa is in negative phase (with a value of "-1"), and the preset gray scale scheme PGPa multiplied by -1 is in the negative value domain. The gray scale information IGRAa of the watermark signal is set to be in the relatively dark state, and thus the second period P1L can be understood as the watermark dark state period.

[0060] The preset gray scale scheme PGPa is generated according to data schemes Pa1-Pa6, and the data schemes Pa1-Pa6 correspond to consecutive periods C1-C3. In some embodiments, in the same period, the integral values of the gray scale values of each data scheme Pa1-Pa6 after time integration are equal to each other, and the sum of the gray scale information IGRAa of the watermark signal in each of the periods C1-C3 is zero.

[0061] For example, in the first period P1H, the data scheme Pa1 includes gray scale values a11-a13. The gray scale values a11-a13 are gray scales of 10, 5, and 15, respectively, and the time lengths are 2t, 1t, and 1t, respectively, where t is an arbitrary positive number. On the other hand, in the second period P1L, the data scheme Pa2 includes gray scale values a21-a23. The gray scale values a21-a23 are gray scale values / gray scale ratios of 10, 5, and 15, respectively, and the time lengths are 2t, 1t, and 1t, respectively. In this way, the integral values of the gray scale values of the data scheme Pa2 of the preset gray scale scheme PGPa are set to be equal to the integral values of the gray scale values of the data scheme Pa1.

[0062] Moreover, the data of the data scheme Pa1 in the first period P1H multiplied by the time series data TSDa of "+1" generates the gray scale information IGRAa of the watermark signal in the first period P1H. On the other hand, the data of the data scheme Pa2 in the second period P1L multiplied by the time series data TSDa of "-1" generates the gray scale information IGRAa of the watermark signal in the second period P2H.

[0063] Thus, in the period C1, the gray scale information IGRAa of the watermark signal is zero in the first period P1H and the second period P1L. In such a case, the gray scale information IGRAa of the watermark signal is embedded in the picture, and it is difficult to perceive that the picture has the watermark due to the visual persistence phenomenon, and in the arrangement case of the data schemes Pa1 to Pa6, the probability that the image photographed after the camera is focused (for example, one of the frames of high luminance or low luminance) has the watermark information is greatly increased.

[0064] It is worth noting that the duration lengths of the gray scale values a11 to a13 are different, which can increase the probability that the camera photographs the picture with the watermark. In other embodiments, the duration lengths of the gray scale values a11 to a13 are the same. Therefore, the present application is not limited thereto.

[0065] In the embodiment of Figure 3 , the data scheme Pa1 and the data scheme Pa2 are translationally symmetrical on the time axis. In other embodiments, the data scheme Pa1 and the data scheme Pa2 are mirror symmetrical or asymmetrical on the time axis. Therefore, the present application is not limited thereto.

[0066] In step S220, the watermark signal is embedded in the first partition dimming signal by the processing circuit 110 to generate a second partition dimming signal DIM2, so that the second partition dimming signal DIM2 carries the watermark information. As shown in Figure 4 , in the period C1, the gray scale information IGRAa of the watermark signal is embedded in the gray scale data GL1 of the first partition dimming signal. For better understanding, all the gray scales originally displayed by the dimming regions (the gray scale data GL1 of the first partition dimming signal) are taken as an example of 150 gray scale values. In the watermark mode, the dimming regions are divided into the watermark display regions and the regions without the watermark.

[0067] For the watermark display regions, the gray scale data GL1 of the first partition dimming signal is adjusted according to the gray scale information IGRAa of the watermark signal to generate the gray scale data GL2W. As shown in Figure 5A and Figure 5B , the gray scale data GL2W is output as the gray scale information of the watermark display regions (for example, each region in the triangular region).

[0068] For the regions without the watermark, the gray scale data GL1 of the first partition dimming signal is directly output as the gray scale data GL2WO. As shown in Figure 5A and Figure 5B , the gray scale data GL2WO is output as the gray scale information of the regions without the watermark (for example, each region outside the triangular region).

[0069] The processing circuit 110 generates the second sub-zone dimming signal SDIM2 according to the gray scale data GL2W and the gray scale data GL2WO, so that the second sub-zone dimming signal SDIM2 carries the watermark information, as shown in Figure 5A and Figure 5B .

[0070] In step S230, the backlight module 120 controls the brightness of the plurality of dimming regions according to the second sub-zone dimming signal SDIM2 carrying the watermark information. As shown in Figure 5A and Figure 5B , the brightness of the watermark (for example, the triangular region in Figure 5A ) shown by the output data 11-16 of the second sub-zone dimming signal SDIM2 is relatively high. The brightness of the watermark (for example, the triangular region in Figure 5B ) shown by the output data 21-26 of the second sub-zone dimming signal SDIM2 is relatively low.

[0071] In addition, since the gray scale information IGRAa of the watermark signal includes the gray scale arrangement in the data scheme Pa1-Pa6, it is difficult to completely avoid the watermark being photographed in the exposure time of the camera, so that the probability of the watermark being photographed by the camera can be greatly improved.

[0072] Please refer to Figures 7 to 8 , Figure 7 for the schematic diagram of the display device 100 and the electronic device DEC according to some embodiments of the present disclosure. Figure 8 for the schematic diagram of the low dynamic watermark signal and the gray scale information IGRAL and IGRA of the watermark signal according to some embodiments of the present disclosure.

[0073] In Figure 7 embodiments, the display device 100 further includes a liquid crystal panel 140. In some embodiments, the processing circuit 110 can extract a first average value from the watermark bright state period of the watermark signal and a second average value from the watermark dark state period of the watermark signal, and output the first average value and the second average value as the gray scale information IGRAL of the low dynamic watermark signal. In this way, the processing circuit 110 can embed the low dynamic watermark signal into the input image VIN to generate an output image VOUT with watermark information to the liquid crystal panel 140, so that the display device 100 displays the sub-frames F1-F6 with the watermark (for example, the triangular pattern) switching between the bright state and the dark state at a high frequency.

[0074] In such a case, the liquid crystal panel 140 and the backlight module 120 of the display device 100 synchronously display the picture according to the gray scale information IGRAL of the low dynamic watermark signal and the gray scale information IGRAa of the watermark signal, so as to enhance the probability and the definition of the captured watermark.

[0075] It is noted that the low dynamic watermark signal of the liquid crystal panel 140 is relative to the watermark signal of the backlight module 120. Both the low dynamic watermark signal and the watermark signal cannot be perceived by human vision. In some embodiments, each of the periods C1-C6 of the gray scale information IGRAL of the low dynamic watermark signal corresponds to a frame length (e.g., 1 / 30, 1 / 60 or 1 / 120 second) of the display device 100.

[0076] Referring to Figure 9 , Figure 9 Figures of the input picture 910, the display picture 921 and 922 and the human visual perception HUMV according to some embodiments of the present disclosure are shown. In Figure 9 some embodiments, the sub-frame picture 921 of the display device 100 corresponds to the sub-frames F1, F3 and F5 of Figure 8 the display device 100. The sub-frame picture 922 of the display device 100 corresponds to the sub-frames F2, F4 and F6 of Figure 8 the display device 100.

[0077] The sub-frame picture 921 contains the watermark in the relatively bright state, and the sub-frame picture 922 contains the watermark in the relatively dark state, so that the display picture carries the information of the watermark. Moreover, the information of the watermark carried by the display picture cannot be perceived by human vision.

[0078] Figure 10A and Figure 10B Figures of the pictures 1010 and 1020 captured by the camera from the screen of the display device 100 according to some embodiments of the present disclosure are shown. As Figure 10A shown, during the camera exposure time, if the average of the gray scale information IGRAa of the watermark signal of the display device 100 has a relatively high gray scale value, the picture 1010 captured by the camera from the screen of the display device 100 will contain the watermark pattern with a high gray scale, such as Figure 10A the "AUO" in the relatively bright state shown in

[0079] Figure 10B shown, during the camera exposure time, if the average of the gray scale information IGRAa of the watermark signal of the display device 100 has a relatively low gray scale value, the picture 1020 captured by the camera from the screen of the display device 100 will contain the watermark pattern with a low gray scale, such as Figure 10B the "AUO" in the relatively dark state shown in

[0080] Figure 11 A diagram of a preset gray scale scheme PGPb, time series data TSDb, and a gray scale message IGRAb of a watermark signal according to some embodiments of the present disclosure is shown. As shown, in a first period P1H, the time series data TSDa is positive phase, and in a second period P1L, the time series data TSDa is negative phase. In some embodiments, the length of the first period P1H is 1 / 3 of a period, and the length of the second period P1L is 2 / 3 of a period. Figure 11 Figure 11

[0081] The time series data TSDb includes data schemes Pb1-Pb6 in a period C3-C3. The average of the gray scale values b11-b12 included in the data scheme Pb1 is equal to the average of the gray scale values b21-b24 included in the data scheme Pb2. The data scheme Pb1 is asymmetric to the data scheme Pb2.

[0082] The configuration of the gray scale values b31-b32 of the data scheme Pb3 is mirror symmetric to the configuration of the gray scale values b11-b12 of the data scheme Pb1. The configuration of the gray scale values b41-b44 of the data scheme Pb4 is mirror symmetric to the configuration of the gray scale values b21-b24 of the data scheme Pb2.

[0083] Thus, the configuration of the gray scale values of the preset gray scale scheme PGPb in a first one of two consecutive periods (e.g., period C1) is mirror symmetric to the configuration of the gray scale values of the preset gray scale scheme PGPb in a second one of the two consecutive periods (e.g., period C2) on the time axis. Also, the gray scale message IGRAb of the watermark signal has gray scale values of “high, low, low” in the first 1 / 3 period, the 1 / 3 to 2 / 3 period, and the 2 / 3 to 3 / 3 period in each of the periods C1-C3, thereby increasing the probability of the watermark being captured by the camera.

[0084] In other embodiments, the configuration of the values of the preset gray scale scheme in a first one of two consecutive periods is translation symmetric to the configuration of the gray scale values of the preset gray scale scheme PGPb in a second one of the two consecutive periods on the time axis. Thus, the present disclosure is not limited thereto.

[0085] Figure 12 A diagram of a preset gray scale scheme PGPb, time series data TSDb, and a gray scale message IGRAb of a watermark signal according to some embodiments of the present disclosure is shown. As shown, in a first period P1H, the time series data TSDa is positive phase, and in a second period P1L, the time series data TSDa is negative phase. In some embodiments, the length of the first period P1H is 1 / 3 of a period, and the length of the second period P1L is 2 / 3 of a period.

[0086] ​​The time series data TSDc contains data schemes Pb1 to Pb6 within periods C3 to C3. The average setting of grayscale values ​​c11 to c14 contained in data scheme Pc1 is equivalent to the average setting of grayscale values ​​c21 to c22 contained in data scheme Pc2. Data schemes Pc1 and Pc2 are asymmetrical.

[0087] and Figure 11 In the embodiments, the grayscale scheme PGPb, time series data TSDb, and grayscale information IGRAB of the watermark signal are compared. Figure 12 The difference between the preset grayscale scheme PcPc, time series data TSDc, and grayscale information IGRAC of the watermark signal in the embodiments is that... Figure 12 In this embodiment, the length of the first period P1H is 2 / 3 of a cycle, and the length of the second period P1L is 1 / 3 of a cycle. This ensures that the grayscale information IGRAC of the watermark signal has a grayscale value of "high, high, low" in the first 1 / 3, 1 / 3 to 2 / 3, and 2 / 3 to 3 / 3 cycles of each period C1 to C3, thereby increasing the probability of the camera capturing the watermark. Other detailed operations of the preset grayscale scheme PGPc, time series data TSDc, and the grayscale information IGRAC of the watermark signal are largely the same as previously described. Figure 11 The grayscale scheme PcPb, time series data TSDb, and grayscale information IGRAB of the watermark signal in the embodiment are preset and will not be described in detail here.

[0088] In summary, the background brightness presented by the backlight module 120 includes a periodically displayed high-dynamic watermark image, and the image displayed by the display device 100 also includes the watermark pattern that the backlight module 120 switches between different gray levels at a high frequency. This increases the probability that the image captured by the camera device of the display device 100 contains identifiable watermark pattern information. Furthermore, due to the high refresh rate of the backlight module 120, the watermark that periodically appears in bright and dark states cannot be perceived by the human eye. Moreover, since the operating frequency of the backlight module 120 is 500kHz to 2MHz, the gray level changes of the watermark within one cycle (e.g., corresponding to the refresh period of the display device 100) can be adjusted more finely, and different durations can be set at each gray level value, thereby increasing the probability that the image captured by the camera device of the display device 100 contains identifiable watermark pattern information.

[0089] Although this disclosure has been described above with reference to embodiments, it is not intended to limit this disclosure. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be determined by the scope defined in the appended claims.

Claims

1. A watermark embedding method, comprising: The processing circuit generates a first-zone dimming signal based on the input image; The processing circuit multiplies the time series data with a preset grayscale scheme to generate grayscale information of the watermark signal. In each of the first periods of multiple consecutive periods and the second period adjacent to the first period, the phase of the time series data is opposite and the average value of the preset grayscale scheme is the same, so that the sum of the grayscale information of the watermark signal is zero. The processing circuit embeds the watermark signal into the first partition dimming signal to generate a second partition dimming signal, so that the second partition dimming signal carries the watermark information. The processing circuit extracts a first average value from the first period of the watermark signal and extracts a second average value from the second period of the watermark signal, and outputs the first average value and the second average value as a low dynamic watermark signal. The processing circuit embeds the low dynamic range watermark signal into the input image signal to generate an output image signal with the watermark message. The backlight module controls the brightness of multiple dimming zones based on the second-zone dimming signal carrying the watermark information; and The LCD panel, in sync with the backlight module, displays an image based on the output image signal containing the watermark information.

2. The watermark embedding method as described in claim 1, comprising: The processing circuit generates the preset grayscale scheme according to the first data scheme in the first period and generates the preset grayscale scheme according to the second data scheme in the second period, wherein the integral of the grayscale value of the first data scheme with respect to time is equal to the integral of the grayscale value of the second data scheme with respect to time, so that the sum of the grayscale information of the watermark signal in the first period and the second period is zero.

3. The watermark embedding method as described in claim 2, wherein the duration of the first period is different from the duration of the second period.

4. The watermark embedding method as described in claim 2, wherein the duration of the first period is equal to the duration of the second period.

5. The watermark embedding method as described in claim 2, wherein the arrangement of grayscale values ​​in the first data scheme and the arrangement of grayscale values ​​in the second data scheme are symmetrically translated on the time axis.

6. The watermark embedding method as described in claim 2, wherein the grayscale value arrangement of the first data scheme and the grayscale value arrangement of the second data scheme are mirror-symmetrical on the time axis.

7. The watermark embedding method as described in claim 1, wherein the arrangement of grayscale values ​​of the preset grayscale scheme in the first period of two consecutive periods is mirror-symmetrical on the time axis with the arrangement of grayscale values ​​of the preset grayscale scheme in the second period of the two consecutive periods.

8. The watermark embedding method as described in claim 1, wherein the grayscale value of the preset grayscale scheme in the first period of two consecutive periods and the grayscale value of the preset grayscale scheme in the second period of the two consecutive periods are translationally symmetrical on the time axis.

9. A display device, comprising: Processing circuitry; A storage device, electrically coupled to the processing circuit, is used to store instructions or data for execution by the processing circuit, wherein the processing circuit is used to: multiplying time series data and a preset gray scale scheme to generate a gray scale message of a watermark signal, wherein phases of the time series data are opposite and average values of the preset gray scale scheme are the same in a first period of each of a plurality of periods and a second period adjacent to the first period, so that a sum of the watermark signal in the first period and the second period is zero; embedding the watermark signal into a first zone dimming signal to generate a second zone dimming signal, so that the second zone dimming signal carries watermark information; extracting a first average value from the first period of the watermark signal and a second average value from the second period of the watermark signal, and outputting the first average value and the second average value as a low dynamic watermark signal; embedding the low dynamic watermark signal into an input image signal to generate an output image signal with the watermark information; a backlight module, wherein the backlight module is used to control brightness of a plurality of dimming regions according to the second zone dimming signal; and a liquid crystal panel, wherein the liquid crystal panel is used to display an image according to the output image signal with the watermark information in synchronization with the backlight module.

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