TWI862170B - Method for displaying watermark frame - Google Patents

Abstract

The disclosure provides a method for displaying a watermark frame, which generates a watermark frame through a processor based on a display data, wherein the watermarked frame includes a watermarked pattern and a frame display area. The watermark frame is displayed through a display panel during a first fame period and a second frame period, wherein a first brightness sum of the watermark frame during the first frame period is the same as a second brightness sum of the watermark frame during the second frame period, wherein a first brightness distribution displayed by the watermark pattern during the first frame period is different from a second brightness distribution displayed thereby during the second frame period, and a third brightness distribution displayed by the frame display area during the first frame period is different from a fourth brightness distribution displayed thereby during the second frame.

Description

How to display the watermark screen

The present invention relates to a display method, and in particular to an image display method for displaying a watermark.

In confidential documents (such as paper documents or electronic documents), watermarks are usually added to warn users and to leave a clear mark when they are copied. However, in the traditional way of displaying watermarks, when the displayed information is similar to the color tone/grayscale of the watermark, it will hinder reading and cause discomfort in reading.

The present invention provides a method for displaying a watermark image, which can reduce the flicker between watermark images containing watermark patterns.

The present invention provides a method for displaying a watermark image, which generates a watermark image through a processor based on display data, wherein the watermark image includes a watermark pattern and an image display area; and displays the watermark image through a display panel during a first image period and a second image period, wherein the first brightness sum of the watermark image during the first image period is the same as the second brightness sum of the watermark image during the second image period, wherein the first brightness distribution of the watermark pattern displayed during the first image period is different from the second brightness distribution displayed during the second image period, and the third brightness distribution of the image display area displayed during the first image period is different from the fourth brightness distribution displayed during the second image period.

Based on the above, in the display method of the watermark image of the embodiment of the present invention, by making the first brightness sum of the watermark image during the first frame period equal to the second brightness sum of the watermark image during the second frame period, the brightness difference perceived by the human eye due to the change in brightness distribution can be suppressed to reduce the flicker between the watermark images.

In order to make the above features and advantages of the present invention more clearly understood, the following is a detailed description of the embodiments with reference to the accompanying drawings.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs. It will be further understood that those terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present invention, and will not be interpreted as an idealized or overly formal meaning unless expressly defined as such herein.

It should be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and/or parts, these elements, components, regions, and/or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, the "first element", "component", "region", "layer" or "part" discussed below can be referred to as a second element, component, region, layer or part without departing from the teachings of this article.

The terms used herein are for the purpose of describing specific embodiments only and are not limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include plural forms, including "at least one". "" or "means" and/or". As used herein, the term "and/or" includes any and all combinations of one or more of the relevant listed items. It should also be understood that when used in this specification, the term "includes" and/or "includes" specifies the presence of the features, regions, wholes, steps, operations, elements, and/or parts, but does not exclude the presence or addition of one or more other features, regions, wholes, steps, operations, elements, parts, and/or combinations thereof.

FIG. 1 is a flow chart of a method for displaying a watermark image according to an embodiment of the present invention. Referring to FIG. 1 , in the present embodiment, the method for displaying a watermark image includes the following steps. In step S110, a watermark image is generated by a processor based on display data, wherein the watermark image includes a watermark pattern and an image display area. In step S120, the watermark image is displayed by a display panel during a first frame period and a second frame period, wherein the sum of the first brightness of the watermark image during the first frame period (i.e., the sum of the brightness displayed by each pixel in the display panel) is the same as the sum of the second brightness of the watermark image during the second frame period. The order of steps S110 and S120 is for illustration, and the embodiments of the present invention are not limited thereto. Furthermore, the details of steps S110 and S120 may refer to the embodiments shown in FIG. 1 to FIG. 8 .

In addition, during a single frame period, the watermark pattern and the pixels with the same grayscale data in the frame display area may have color difference, that is, display different brightness, so that the watermark pattern is obvious to the image capture device. Moreover, the first brightness distribution (that is, the distribution presented by the brightness displayed by all pixels in the display panel) of the watermark pattern during the first frame period is different from the second brightness distribution displayed during the second frame period, and the third brightness distribution displayed by the frame display area during the first frame period is different from the fourth brightness distribution displayed during the second frame period, wherein the first brightness distribution and the fourth brightness distribution can refer to the same gamma curve, and the second brightness distribution and the third brightness distribution can refer to another gamma curve, so that the watermark becomes inconspicuous to the human eye.

According to the above, by making the first brightness sum of the watermark picture in the first frame period equal to the second brightness sum of the watermark picture in the second frame period, the brightness difference perceived by the human eye due to the change in brightness distribution can be suppressed to reduce the flicker between the watermark pictures.

FIG. 2 is a schematic diagram of a watermark screen according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a display timing of a watermark screen according to an embodiment of the present invention. Referring to FIG. 2 and FIG. 3, in the present embodiment, a watermark screen 100 generated according to display data may include a watermark pattern 110 and a screen display area 120, and may be displayed at least in a first screen period FP1 and a second screen period FP2, that is, the watermark screen 100 may be a static display screen, but the present embodiment is not limited thereto.

Further, during the first frame period FP1, the watermark pattern 110 presents (or displays) a brightness distribution Gd1 (corresponding to the first brightness distribution), and the frame display area 120 presents a brightness distribution Gd2 (corresponding to the third brightness distribution). During the second frame period FP2, the watermark pattern 110 presents a brightness distribution Gd3 (corresponding to the second brightness distribution), and the frame display area 120 presents a brightness distribution Gd4 (corresponding to the fourth brightness distribution). The first brightness sum TBr1 of the watermark frame 100 during the first frame period FP1 is the same as the second brightness sum TBr2 of the watermark frame 100 during the second frame period FP2. The first brightness distribution Gd1 of the watermark pattern 110 displayed in the first frame period FP1 is different from the second brightness distribution Gd3 displayed in the second frame period FP2, and the third brightness distribution Gd2 of the frame display area 120 displayed in the first frame period FP1 is different from the fourth brightness distribution Gd4 displayed in the second frame period FP2.

In the embodiment of the present invention, the brightness distribution of the watermark pattern 110 and the screen display area 120 varies with time, so the ratio of the area of the watermark pattern 110 to the area of the screen display area 120 will affect the change of the total brightness (such as TBr1, TBr2). That is, when the area of the watermark pattern 110 is closer to the area of the screen display area 120, the change of the total brightness (such as TBr1, TBr2) of the watermark screen 100 will become smaller accordingly. In one embodiment of the present invention, the area of the watermark pattern 110 can be the same as the area of the screen display area 120.

FIG. 4 is a schematic diagram of a gamma curve of a display method according to an embodiment of the present invention. Referring to FIG. 2 to FIG. 4, in the present embodiment, the watermark screen 100 is divided into two parts (i.e., the watermark pattern 110 and the screen display area 120), and the display panel can be driven by at least two gamma curves (e.g., a first gamma curve Gamma1 and a second gamma curve Gamma2). For example, the brightness distribution Gd1 and the brightness distribution Gd4 can be determined based on the first gamma curve Gamma1, and the brightness distribution Gd3 and the brightness distribution Gd2 can be determined based on the second gamma curve Gamma2 different from the first gamma curve Gamma1, but the present embodiment is not limited thereto.

FIG. 5 is a schematic diagram of a watermark screen according to another embodiment of the present invention. FIG. 6 is a schematic diagram of a display timing of a watermark screen according to another embodiment of the present invention. Referring to FIG. 6, in this embodiment, a watermark screen 200 generated according to display data may include a watermark pattern 110 and a screen display area 220, wherein the screen display area 220 includes at least one first sub-display area (here, two sub-display areas 221 are used as an example) and at least one second display area (here, two second display areas 222 are used as an example). And the watermark screen 200 is displayed at least in the first screen period FP1, the second screen period FP2, and the third screen period FP3, that is, the watermark screen 200 may be a static display screen, but the embodiment of the present invention is not limited thereto.

Specifically, during the first frame period FP1, the watermark pattern 110 presents the brightness distribution Gd1, the first sub-display area 221 presents the sub-brightness distribution Gds1 (corresponding to the first sub-brightness distribution), and the second sub-display area 222 presents the sub-brightness distribution Gds2 (corresponding to the fourth sub-brightness distribution). During the second frame period FP2, the watermark pattern 110 presents the brightness distribution Gd3, the first sub-display area 221 presents the sub-brightness distribution Gds3 (corresponding to the second sub-brightness distribution), and the second sub-display area 222 presents the sub-brightness distribution Gds4 (corresponding to the fifth sub-brightness distribution). During the third frame period FP3, the watermark pattern 110 presents the brightness distribution Gd5 (corresponding to the fifth brightness distribution), the first sub-display area 221 presents the sub-brightness distribution Gds5 (corresponding to the third sub-brightness distribution), and the second sub-display area 222 presents the sub-brightness distribution Gds6 (corresponding to the sixth sub-brightness distribution). The total brightness TBx3 (corresponding to the third total brightness) of the watermark image 200 during the third frame period FP3 may be the same as the total brightness TBx1 of the watermark image 200 during the first frame period FP1 and the total brightness TBx2 of the watermark image 200 during the second frame period FP2, that is, the total brightness TBx1, TBx2 and TBx3 may be completely the same or almost the same, which may depend on the circuit design, and the embodiment of the present invention is not limited thereto.

In this embodiment, the brightness distribution Gd1, brightness distribution Gd3 and brightness distribution Gd5 of the watermark pattern 110 are different from each other, the sub-brightness distribution Gds1, sub-brightness distribution Gds3, and sub-brightness distribution Gds5 of the first sub-display area 221 are different from each other, and the sub-brightness distribution Gds2, sub-brightness distribution Gds4, and sub-brightness distribution Gds6 of the second sub-display area 222 are different from each other.

In the embodiment of the present invention, the brightness distribution of the watermark pattern 110, the first sub-display area 221 and the second sub-display area 222 varies with time, so the ratio of the areas of the watermark pattern 110, the first sub-display area 221 and the second sub-display area 222 will affect the variation of the total brightness (such as TBx1, TBx2, TBx3). In other words, when the ratio of the areas of the watermark pattern 110, the first sub-display area 221 and the second sub-display area 222 is more exclusive, the variation of the total brightness (such as TBx1, TBx2, TBx3) of the watermark screen 100 will become smaller accordingly. In one embodiment of the present invention, the areas of the watermark pattern 110, the first sub-display area 221 and the second sub-display area 222 may be the same.

FIG7 is a schematic diagram of a gamma curve of a display method according to an embodiment of the present invention. Referring to FIG5 to FIG7, in this embodiment, the corresponding watermark image 200 is divided into three parts (i.e., the watermark pattern 110, two sub-display areas 221, and two second display areas 222), and the display panel can be driven by at least three gamma curves (e.g., a first gamma curve Gamma1, a second gamma curve Gamma2, and a third gamma curve Gamma3). For example, brightness distribution Gd1, sub-brightness distribution Gds3, and sub-brightness distribution Gds6 can be determined based on the first gamma curve Gamma1, brightness distribution Gd2, sub-brightness distribution Gds5 and sub-brightness distribution Gds2 can be determined based on the second gamma curve Gamma2 different from the first gamma curve Gamma1, and brightness distribution Gd5, sub-brightness distribution Gds1 and sub-brightness distribution Gds4 can be determined based on the third gamma curve Gamma3 different from the first gamma curve Gamma1 and the second gamma curve Gamma2.

In the above-mentioned embodiment, when the watermark screen 100 is divided into two parts (i.e., the watermark pattern 110 and the screen display area 120) for driving, the areas of the two parts can be 1/2 of the area of the watermark screen 100 respectively, so that the change of the total brightness of the watermark screen 100 becomes smaller; when the watermark screen 200 is divided into three parts (i.e., the watermark pattern 110, the two sub-display areas 221 and the two second display areas 222) for driving, the areas of the three parts can be 1/3 of the area of the watermark screen 200 respectively, so that the change of the total brightness of the watermark screen 200 becomes smaller. That is, when the watermark image (such as 100, 200) is divided into N parts for driving, the area of each part can be 1/N of the area of the watermark image (such as 100, 200), so as to reduce the change of the total brightness of the watermark image (such as 100, 200), where N is a positive integer greater than or equal to 2.

FIG8 is a system schematic diagram of a display device according to an embodiment of the present invention. Referring to FIG8 , in this embodiment, the display device system 300 at least includes an image processing circuit 310, a timing controller 320, a source driver 330, a gate driver 340, and a display panel 350, wherein a plurality of pixels PX (e.g., arranged in an array) may be configured on the display panel 350. In addition, the timing controller 320 is coupled to the image processing circuit 310, the source driver 330, and the gate driver 340. The display panel 350 is coupled to the source driver 330 and the gate driver 340.

After receiving the input image data DTin, the image processing circuit 310 may output the display data DTdisp generated based on the input image data DTin to the timing controller 320. Then, the timing controller 320 may output the first control signal CSg to the gate driver 340 based on the display data DTdisp, and output the second control signal CSd to the source driver 330, wherein the first control signal CSg may control the gate driver 340, and the second control signal CSd may control the source driver 330. The gate driver 340 can provide a gate signal SG to the display panel 350 based on the first control signal CSg to turn on the pixels PX row by row, and the source driver 330 can output the pixel voltage Vpx to the display panel 350 based on the second control signal CSd to write the grayscale value corresponding to each pixel PX into each pixel PX based on the display data DTdisp. In the embodiment of the present invention, at least a part of the display method of the watermark screen shown in Figures 1 to 7 can be operated in the image processing circuit 310 and/or the timing controller 320, but the embodiment of the present invention is not limited thereto.

In summary, in the method for displaying a watermark image of the embodiment of the present invention, the total first brightness of the watermark image during the first frame period is equal to the total second brightness of the watermark image during the second frame period, so as to suppress the brightness difference perceived by the human eye due to the change in brightness distribution, thereby reducing the flicker between watermark images.

Although the present invention has been disclosed as above by the embodiments, they are not intended to limit the present invention. Any person with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the scope of the attached patent application.

100, 200: watermark screen 110: watermark pattern 120, 220: screen display area 221: first sub-display area 222: second sub-display area 300: display device system 310: image processing circuit 320: timing controller 330: source driver 340: gate driver 350: display panel CSd: first control signal CSg: second control signal DTdisp: display data DTin: input image data FP1, FP2, FP3: screen period Gamma1: first gamma curve Gamma2: second gamma curve Gamma3: third gamma curve Gd1, Gd2, Gd3, Gd4, Gd5: brightness distribution Gds1, Gds2, Gds3, Gds4, Gds5, Gds6: sub-brightness distribution PX: pixel TBr1, TBr2, TBx1, TBx2, TBx3: total brightness Vpx: pixel voltage SG: gate signal S110, S120: steps

FIG. 1 is a flow chart of a method for displaying a watermark screen according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a watermark screen according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a display timing of a watermark screen according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a gamma curve of a method for displaying a watermark screen according to an embodiment of the present invention. FIG. 5 is a schematic diagram of a watermark screen according to another embodiment of the present invention. FIG. 6 is a schematic diagram of a display timing of a watermark screen according to another embodiment of the present invention. FIG. 7 is a schematic diagram of a gamma curve of a method for displaying a watermark screen according to another embodiment of the present invention. FIG. 8 is a system schematic diagram of a display device according to an embodiment of the present invention.

S110, S120: Steps

Claims (8)

A method for displaying a watermark image comprises: generating a watermark image through a processor based on display data, wherein the watermark image comprises a watermark pattern and an image display area; and displaying the watermark image through a display panel in a first image period and a second image period, wherein the watermark image has a first brightness that is the sum of a plurality of first brightnesses displayed by all a plurality of pixels in the display panel during the first image period. The sum is equal to a second brightness sum of the sum of multiple second brightnesses displayed by all the pixels of the watermark image during the second image period, wherein a first brightness distribution displayed by the watermark pattern during the first image period is different from a second brightness distribution displayed during the second image period, and a third brightness distribution displayed by the image display area during the first image period is different from a fourth brightness distribution displayed during the second image period. The display method described in claim 1, wherein the first brightness distribution and the fourth brightness distribution are determined based on a first gamma curve, and the second brightness distribution and the third brightness distribution are determined based on a second gamma curve different from the first gamma curve. A display method as described in claim 2, wherein the area of the watermark pattern is the same as the area of the screen display area. The display method as described in claim 1 further comprises: displaying the watermark image via the display panel during a third frame period, wherein a third brightness sum of the watermark image during the first frame period is equal to the first brightness sum and the second brightness sum of the watermark image. The display method as described in claim 4, wherein the screen display area includes at least one first sub-display area and at least one second display area. The display method as described in claim 5, wherein a fifth brightness distribution of the watermark pattern displayed during the third frame is different from the first brightness distribution and the second brightness distribution, a first sub-brightness distribution displayed during the first frame, a second sub-brightness distribution displayed during the second frame, and a third sub-brightness distribution displayed during the third frame of the at least one first sub-display area are different from each other, and a fourth sub-brightness distribution displayed during the first frame, a fifth sub-brightness distribution displayed during the second frame, and a sixth sub-brightness distribution displayed during the third frame of the at least one second sub-display area are different from each other. The display method as described in claim 6, wherein the first brightness distribution, the second sub-brightness distribution, and the sixth sub-brightness distribution are determined based on a first gamma curve, the second brightness distribution, the third sub-brightness distribution, and the fourth sub-brightness distribution are determined based on a second gamma curve different from the first gamma curve, and the fifth brightness distribution, the first sub-brightness distribution, and the fifth sub-brightness distribution are determined based on a third gamma curve different from the first gamma curve and the second gamma curve. The display method as described in claim 7, wherein the area of the watermark pattern, the area of the at least one first display area, and the area of the at least one second display area are the same as each other.

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