A watermark generating apparatus that is invisible to the human eye

Abstract

An apparatus for generating a watermark on an image according to one embodiment of the present disclosure comprises an image recognition unit that recognizes an image of a specific region of the image, an image analysis unit that extracts colors from the image of the specific region, and a watermark information generation unit that generates the watermark, wherein the image analysis unit matches a target color having the maximum number among the colors extracted from the image of the specific region, and the color of the watermark may correspond to the target color by combining a plurality of colors.

Description

Technology Field

[0001] The content of the present disclosure relates to a watermark generating device, and more specifically, to a device that generates a watermark that is not visible to the human eye on a screen displayed on an image but is visible in an image captured from the image. Background Technology

[0003] With the miniaturization of semiconductor circuits and the advancement of high-density integrated circuit technologies, camera modules capable of capturing images of objects are being installed in small smartphones, replacing conventional standard cameras. Individuals can easily capture images of desired objects while carrying small smartphones for personal use. Furthermore, it has recently become common practice to handle work within a company using ICT technology. Typically, employees working in-house acquire and process information using display screens on monitors such as desktops or laptops. In this scenario, individuals can easily access security data displayed on the screen that is prohibited from being leaked externally, and they can easily photograph and possess such data. For instance, not only can an individual photograph security data with the intent to leak it externally, but there may also be cases where data stored on a smartphone is leaked through hacking. In the former case, tracing the leakage path of the security data may be relatively easy, whereas in the latter case, it is difficult to identify the leakage route. In addition, if a watermark that can identify an individual is additionally displayed on the display screen to identify the leakage path of security data, it may interfere with other textures on the display and reduce work efficiency. Prior art literature

[0004] Korean Published Patent Application No. 10-2022-0157853 (Title of Invention: Device and Method for Preventing Screen Data Leakage, Date of Publication: Nov. 29, 2022) The problem to be solved

[0005] The present disclosure is devised in response to the aforementioned background technology and has one objective of providing a watermark generating device capable of efficiently displaying a watermark on an image.

[0006] In addition, the present disclosure has one objective of providing a device that generates a watermark that is invisible to the eyes of a person viewing a display screen but visible to an image captured of the display screen.

[0007] The purpose is to provide security technology that utilizes the difference between the human eye, which perceives objects slowly, and a camera, which captures images relatively quickly.

[0008] However, the problems to be solved in this disclosure are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs from this specification and the attached drawings. means of solving the problem

[0009] A watermark generating device according to one embodiment of the present disclosure is disclosed for realizing the aforementioned objectives. A device for generating a watermark on an image according to one embodiment includes an image recognition unit that recognizes an image of a specific area of ​​the image, an image analysis unit that extracts colors from the image of the specific area, and a watermark information generating unit that generates the watermark. The image analysis unit matches a target color having the maximum number among the colors extracted from the image of the specific area, and the color of the watermark may correspond to the target color by combining a plurality of colors.

[0010] Alternatively, the watermark may be composed of a combination of a first watermark having a first color combination and a second watermark having a second color combination different from the first color combination, and the first watermark and the second watermark may be repeatedly output in the same area of ​​the specific area.

[0011] Alternatively, the first watermark may be output to the image during an odd number of frames that appear during one second of the image, and the second watermark may be output to the image during an even number of frames that appear during one second of the image.

[0012] Alternatively, the first color combination and the second color combination may be repeatedly output to the specific area above so that the first color combination and the second color combination overlap with the human eye and are recognized as the target color.

[0013] Alternatively, the watermark may be composed of a combination of a first watermark having a first color combination, a second watermark having a second color combination, and a third watermark having a third color combination, wherein the first color combination, the second color combination, and the third color combination may be different from each other.

[0014] Alternatively, the first watermark, the second watermark, and the third watermark may be alternately output to the same area of ​​the specific area, the first watermark may be output to the image N times (N is a natural number) during which a frame appears for 1 second of the image, the second watermark may be output to the image N+1 times during which a frame appears for 1 second of the image, and the third watermark may be output to the image N+2 times during which a frame appears for 1 second of the image.

[0015] Alternatively, the above watermark may be composed of colors consisting of four or more natural numbers.

[0016] Alternatively, the image analysis unit can calculate the maximum area formed by adjacent unit blocks having the target color within the specific area.

[0017] Alternatively, the image analysis unit may set the maximum area as the target area where the watermark is to be output.

[0018] Alternatively, a watermark output unit that outputs the watermark generated by the watermark information generation unit to the image may be further included.

[0019] Alternatively, the watermark output unit may output the watermark to the target area.

[0020] Alternatively, the watermark output unit may output the watermark to the image such that the number of frames appearing during one second of the image is proportional to the number of colors included in the color combination of the watermark. Effects of the invention

[0022] According to one embodiment of the present disclosure, a watermark can be efficiently displayed on an image.

[0023] In addition, according to one embodiment of the present disclosure, a watermark can be generated that is not visible to the eyes of a person viewing the display screen but is visible to an image captured of the display screen.

[0024] In addition, according to one embodiment of the present disclosure, security can be enhanced without reducing work efficiency.

[0025] The effects of the present disclosure are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from the present specification and the accompanying drawings. Brief explanation of the drawing

[0027] FIG. 1 is a schematic diagram showing a watermark generating device and an image display device according to one embodiment of the present disclosure. Figure 2 is a block diagram schematically showing the watermark generating device of Figure 1. FIGS. 3 to 5 are schematic diagrams for sequentially explaining the mechanism of the watermark generating device of FIG. 1 generating and outputting a watermark on an image. Specific details for implementing the invention

[0028] Hereinafter, embodiments of the present disclosure are described in detail with reference to the attached drawings so that those skilled in the art can easily practice the present disclosure. Embodiments of the present disclosure may be modified and implemented in various forms and are not limited to the embodiments described below. Furthermore, the embodiments described below are provided to enable those skilled in the art to explain the present disclosure more completely. Accordingly, the shapes of components in the drawings are exaggerated to emphasize clear explanations. Additionally, in describing preferred embodiments of the present disclosure in detail, if it is determined that a detailed description of related known functions or configurations could unnecessarily dilute the essence of the present disclosure, such detailed description is omitted. Also, the same reference numerals are used throughout the drawings for parts having similar functions and operations.

[0029] The term 'comprising' a component means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components. Specifically, terms such as 'comprising' or 'having' refer to the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0030] Singular expressions include plural expressions unless the context clearly indicates otherwise. Additionally, terms such as "first," "second," etc., may be used to describe various components, but said components are not limited by said terms. These terms may be used for the purpose of distinguishing one component from another. For example, without departing from the scope of the rights of this disclosure, the first component may be named the second component, and similarly, the second component may be named the first component.

[0031] In context, the expression 'less than' can be used to include the meaning of 'less than,' and the expression 'more than' can be understood to include the meaning of 'exceeding.'

[0032] Unless otherwise defined, all terms used, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted in a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined below.

[0033] A watermark generating device according to an embodiment of the present disclosure may be a device for generating and outputting a watermark on an image.

[0034] Here, the term "image" may be defined as a general term for an image appearing on a screen, regardless of the type of screen. For example, in the present disclosure, the term "image" may be an image appearing on a desktop monitor screen, an image appearing on a mobile screen (including PDPs, mobile phones, etc.), or an image appearing on a portable laptop monitor screen. Furthermore, it is not limited to the type of display device, such as an LCD (Liquid Crystal Display), PDP (Plasma Display Panel), or OLED (Organic Light Emitting Diodes). In addition, the watermark of the present disclosure may be displayed on the image for each frame generated by the display. For example, if 60 frames are displayed on the screen of a display for one second, the display is understood to have a screen refresh rate of 60 Hz, and the watermark of the present disclosure may be displayed on the image 60 times per second.

[0035] Herein, a watermark may be defined as a combination of shapes, characters, and / or sequences of numbers displayed for security purposes. For example, the watermark may be the employee number of a specific person working within the company. Furthermore, the watermark of the present disclosure is sufficient if it is of a size identifiable to the human eye. However, it is not limited thereto, and the watermark of the present disclosure should be understood as a concept that includes all means capable of identifying a specific person. Additionally, the watermark of the present disclosure may have colors expressed in RGB. That is, the watermark of the present disclosure may have various types of colors that can be expressed as a combination of the three RGB colors. Although the RGB color model has been used as an example in the present disclosure, it is not limited thereto, and various color models such as CMY and HSV may be used.

[0036] Hereinafter, a watermark generating device according to one embodiment of the present disclosure will be described in detail with reference to the attached drawings.

[0038] FIG. 1 is a schematic diagram showing a watermark generating device and an image display device according to one embodiment of the present disclosure. FIG. 2 is a block diagram showing the watermark generating device of FIG. 1 in a schematic manner. FIG. 3 to 5 are schematic diagrams for sequentially explaining a mechanism for the watermark generating device of FIG. 1 to generate and output a watermark on an image.

[0040] As illustrated in FIG. 1, a watermark generating device (100) according to one embodiment is connected to a display (10). The type of display (10) is not limited as described above. Additionally, the watermark generating device (100) may be wirelessly connected to the display (10). Furthermore, the watermark generating device (100) may be wired to the display (10). In addition, instead of being directly connected to the display (10), the watermark generating device (100) may be wirelessly or wiredly connected to a video card, graphics card, or other OS (SW) driving driver that transmits an image to the display (10). In another embodiment, the watermark generating device (100) may be installed as a firmware to an OS (SW) driving driver, etc., and may generate and output a watermark on an image of the display (10) by executing the said firmware.

[0042] As illustrated in FIG. 2, a watermark generating device (100) according to one embodiment generates and outputs a watermark on an image of a display (10), and may include an image recognition unit (110), an image analysis unit (120), a watermark information generating unit (130), and a watermark output unit (140).

[0043] An image recognition unit (110) according to one embodiment recognizes an image of an image currently displayed on a display (10). Specifically, the image recognition unit (110) can recognize an image of a specific area of ​​the image. A specific area may refer to the entire area of ​​the image displayed on the display (10), or may refer to an area of ​​a part of the entire area of ​​the image.

[0044] For example, as illustrated in FIG. 3, the image recognition unit (110) may divide the entire area of ​​the image displayed on the display (10) into four parts and recognize any one of the parts (e.g., the upper right area) as a specific area (MA). However, this is merely an example for convenience of understanding and the present disclosure is not limited thereto.

[0045] In addition, the image recognition unit (110) can obtain an image of a specific area (MA) by dividing it into unit blocks. A unit block may refer to a block having a set width and height. For example, a unit block may be 1 pixel in size, but this is merely an example. Accordingly, the image recognition unit (110) can obtain at least one unit block image of a specific area (MA).

[0046] An image analysis unit (120) according to one embodiment receives an image of a specific region (MA) recognized by an image recognition unit (110). As described above, since the image recognition unit (110) can obtain an image of a specific region (MA) by dividing it into unit blocks, the image analysis unit (120) can also receive at least one unit block image included in the specific region (MA) from the image recognition unit (110).

[0047] The image analysis unit (120) extracts colors from an image of a specific area (MA) received. Specifically, the image analysis unit (120) distinguishes and individually extracts the colors of each unit block image included in the specific area (MA). For example, as shown in FIG. 3, approximately 90% of the colors of the unit block images within the specific area (MA) may be extracted as yellow, approximately 8% as gray, and approximately 2% as white. In this case, the image analysis unit (120) can extract the main color as yellow from the image of the specific area (MA) and match that color as the target color. That is, the image analysis unit (120) matches the color having the maximum number among the colors extracted within the image of the specific area (MA) as the target color. In one embodiment, the target color is preferably a color that can be created by a combination of two or more colors in RGB. If the target color is matched but is not a color that can be created by combining two or more colors, the color with the next highest number can be matched as the target color.

[0048] Additionally, the image analysis unit (120) evaluates the adjacency of unit blocks having colors matched to the target color within a specific area (MA) received. Specifically, the image analysis unit (120) calculates the areas formed by adjacent unit blocks having the target color within the specific area (MA). For example, as illustrated in FIG. 3, the image analysis unit (120) calculates areas (A1, A2, TA) formed by unit blocks having the target color yellow, and evaluates the size of each area (A1, A2, TA) by comparing them. The image analysis unit (120) sets the area having the maximum area among the calculated areas (A1, A2, TA) as the target area (TA) where the watermark will be displayed. As will be described in detail below, the target area (TA) functions as the area where the watermark will be output. That is, the image analysis unit (120) of the present disclosure can set the target area (TA) to maximize the area where the watermark will be output. This is because, while desktop displays relatively often have sufficient area to display a watermark, displays of small devices such as mobile phones often do not have sufficient area to display a watermark, so the present disclosure can be effectively applied to displays of small devices.

[0049] A watermark information generating unit (130) according to one embodiment generates a watermark on an image. The watermark generated by the watermark information generating unit (130) may have a certain pattern (e.g., a stripe pattern, a grid pattern, etc.). Conversely, the watermark according to one embodiment may be formed without a pattern. In addition, the watermark may be composed of a combination of numbers, letters, and / or shapes as described above. Hereinafter, for convenience of explanation, the case where the watermark according to one embodiment is the English letter "S" as shown in FIG. 4 will be described as an example.

[0050] The watermark information generation unit (130) generates M or more watermarks (M is a natural number greater than or equal to 2). Additionally, the watermarks generated by the watermark information generation unit (130) have different color combinations. For example, as illustrated in FIG. 4(a), the watermark information generation unit (130) can generate a first watermark (WM1) and a second watermark (WM2). According to one example, the first watermark (WM1) may have a first color combination, and the second watermark (WM2) may have a second color combination. Each color combination constituting each watermark may be different from one another. Additionally, each color combination constituting each watermark may have a symmetrical structure relative to one another. Furthermore, each color combination constituting each watermark may have the same type of color. That is, each color combination constituting each watermark may have the same type of color, but may have a structure in which the same colors are arranged symmetrically (or alternately).

[0051] For example, as illustrated in FIG. 4(a), the first color combination of the first watermark (WM1) may be red on the left side and green on the right side, based on a center line penetrating the top and bottom of the English letter "S". Additionally, the second color combination of the second watermark (WM1) may be green on the left side and red on the right side, based on a center line penetrating the top and bottom of the English letter "S". Although the above example is based on a center line penetrating the top and bottom, it is not limited thereto, and the color division and color combination can be freely modified within the scope that can be easily changed by a person skilled in the art.

[0052] A watermark output unit (140) according to one embodiment outputs watermarks (WM1, WM2) generated by a watermark information generation unit (130) to the aforementioned target area (TA). At this time, the watermark output unit (140) repeatedly outputs each of the watermarks (WM1, WM2) to the same area. Specifically, the watermark output unit (140) repeatedly outputs the first watermark (WM1) and the second watermark (WM2) to the same area within the target area (TA). In addition, the watermark output unit (140) alternately outputs the watermarks (WM1, WM2) for each frame generated on the display (10). For example, assuming the refresh rate of the display is 60Hz, the first watermark (WM1) can be output on the display (10) image at odd times when the image appears in the frame for 1 second, and the second watermark (WM2) can be output on the display (10) image at even times when the image appears in the frame for 1 second. That is, the first watermark (WM1) and the second watermark (WM2) can be output at the same location within the target area (TA) by switching alternately 30 times each during 1 second.

[0053] Accordingly, the first watermark (WM1) and the second watermark (WM2) are respectively output to the image of the display (10) as in FIG. 4(a), but the eye of the person viewing the image perceives a watermark (WM) in which the first watermark (WM1) and the second watermark (WM2) are superimposed due to the difference in speed between the organ that receives light and the organ that transmits it, as in FIG. 4(b) (in FIG. 4(b), the outline of the watermark (WM) is indicated as a dotted line for ease of understanding, but the outline dotted line is not visible to the human eye). That is, due to the flicker principle, the target color of the target area (TA) and the color of the watermark (WM) perceived by the human eye become identical. As a result, the watermark (WM) in which the first watermark (WM1) and the second watermark (WM2) are superimposed is not visible to the eye of the person viewing the image. In contrast, when a specific person captures an image using a camera or the like, either the first watermark (WM1) or the second watermark (WM2) displayed on the target area (TA) on the image is displayed.

[0054] According to the embodiment of the present disclosure described above, a watermark can be clearly displayed on an image captured without being visible to the human eye. Accordingly, the security of the image can be efficiently enhanced without reducing the efficiency of the worker viewing the image.

[0056] In the example described above, the case where the watermark generated by the watermark information generation unit (130) is two (i.e., combined with two colors) was explained as an example, but it is not limited thereto. For example, the watermark information generation unit (130) can generate a first watermark, a second watermark, and a third watermark, respectively, and the first watermark can be composed of a first color combination, the second watermark of a second color combination, and the third watermark of a third color combination. In addition, the first color combination, the second color combination, and the third color combination may be different from each other. For example, when the target color is white, the first color combination, the second color combination, and the third color combination may each be divided into three vertically. At this time, the first color combination may be composed of a combination of red on the left, green in the center, and blue on the right, the second color combination may be composed of a combination of green on the left, blue in the center, and red on the right, and the third color combination may be composed of a combination of blue on the left, red in the center, and green on the right. Additionally, the first watermark can be displayed on the image N times (N is a natural number) that appear in the frame during one second of the image, the second watermark can be displayed on the image N+1 times that appear in the frame during one second, and the third watermark can be displayed on the image N+2 times that appear in the frame during one second. That is, the first watermark, the second watermark, and the third watermark can be switched and displayed at the same location on the image. Accordingly, the final color of the watermark displayed on the image can be perceived by the human eye as white, which is the same as the target color of the target area.

[0057] Of course, the above mechanism can be applied in the same way even when the watermark generated by the watermark information generation unit (130) is combined with four or more colors and output on the image. In addition, the number of frames appearing on the image of the display for one second may be proportional to the number of colors in the watermark generated by the watermark information generation unit (130). For example, if the number of colors in the watermark is two, the refresh rate of the display may be 120 Hz, and if the number of colors in the watermark is three, the refresh rate of the display may be 180 Hz. In this disclosure, the refresh rate is described as an example based on multiples of 60, but it is not limited thereto; the standard refresh rate may be set in a range other than 60 Hz, and the refresh rate of the display may be set in proportion to the number of colors in the watermark and the standard refresh rate. If the range of the adjustable refresh rate of the display is determined, the number of colors that the watermark may have may be determined according to the refresh rate.

[0059] In addition to the above-described embodiment, the watermark generation device (100) of the present disclosure may preemptively compare the brightness of an image within a specific area (MA) before extracting a color from an image of a specific area (MA) received by an image analysis unit (120). That is, the image analysis unit (120) may adaptively determine whether there are many dark pixels or many white pixels and compare the number of such pixels to select an optimal area within the specific area (MA) as a target area (TA). For example, depending on the color or brightness within the image, an area that is relatively unobtrusive to the human eye and displays the watermark well on the captured image may be selected as the target area (TA).

[0061] In addition to the embodiments described above, the watermark generating device (100) of the present disclosure can generate and output watermarks differently depending on the type of display. For example, in the case of a desktop monitor, since the overall image size is relatively large, the output location of the watermark can be secured relatively widely, so the pattern of the watermark to be output on the image can be varied, and the size of the watermark can also be generated and output relatively large. In contrast, in the case of a mobile screen, since the overall image size is relatively small, it is difficult to secure the output location of the watermark relatively. In this case, the pattern of the watermark to be output on the image can be simplified, and the size of the watermark can also be generated and output relatively small. In addition, the watermark generating device (100) of the present disclosure can output the generated watermark even in the area where text is displayed on the image of the display in order to make it difficult for a specific person to arbitrarily edit an image captured by a specific person. In addition, different watermarks with different patterns, text, and shapes can be generated and output to the areas (A1, A2, TA) described with reference to FIG. 3, respectively. For example, a watermark consisting of affiliation can be printed in one area (A1), a watermark consisting of position can be printed in another area (A2), and a watermark consisting of employee number can be printed in yet another area (TA).

[0063] The above detailed description is illustrative of the present disclosure. Furthermore, the foregoing describes preferred embodiments of the present disclosure, and the present disclosure may be used in various other combinations, modifications, and environments. That is, modifications or alterations are possible within the scope of the concept of the present disclosure, the scope equivalent to the described disclosure, and / or the scope of the art or knowledge. The described embodiments describe the best state for implementing the technical concept of the present disclosure, and various modifications required for specific fields of application and uses of the present disclosure are possible. Accordingly, the above detailed description of the invention is not intended to limit the present disclosure to the disclosed embodiments. Furthermore, the appended claims should be interpreted as including other embodiments.

Claims

Claim 1 A watermark generating device for generating a watermark on an image, comprising: an image recognition unit that recognizes an image of a specific area of ​​the image; an image analysis unit that extracts colors from the image of the specific area; and a watermark information generating unit that generates the watermark, wherein the image analysis unit matches a target color having the maximum number among the colors extracted from the image of the specific area, and the color of the watermark corresponds to the target color by combining a plurality of colors, and the watermark is composed of a combination of a first watermark having a first color combination and a second watermark having a second color combination different from the first color combination, and wherein the first watermark and the second watermark are repeatedly output to the same area of ​​the specific area. Claim 2 delete Claim 3 A watermark generating device according to claim 1, characterized in that the first watermark is output to the image during an odd number of frames that appear during one second of the image, and the second watermark is output to the image during an even number of frames that appear during one second of the image. Claim 4 A watermark generating device according to claim 3, characterized in that the first color combination and the second color combination are repeatedly output to the specific area so that the first color combination and the second color combination overlap with the human eye and are recognized as the target color. Claim 5 A watermark generating device according to claim 1, wherein the watermark is composed of a combination of a first watermark having a first color combination, a second watermark having a second color combination, and a third watermark having a third color combination, wherein the first color combination, the second color combination, and the third color combination are different from each other. Claim 6 A watermark generating device according to claim 5, wherein the first watermark, the second watermark, and the third watermark are alternately output to the same area of ​​the specific area, the first watermark is output to the image N times (N is a natural number) during which a frame appears for 1 second of the image, the second watermark is output to the image N+1 times during which a frame appears for 1 second of the image, and the third watermark is output to the image N+2 times during which a frame appears for 1 second of the image. Claim 7 A watermark generating device according to claim 1, characterized in that the watermark is composed of colors consisting of four or more natural numbers. Claim 8 A watermark generating device according to claim 1, wherein the image analysis unit calculates the maximum area formed by adjacent unit blocks having the target color within the specific area. Claim 9 A watermark generating device according to claim 8, wherein the image analysis unit sets the maximum area as the target area to be outputted with the watermark. Claim 10 A watermark generating device according to claim 9, further comprising a watermark output unit that outputs the watermark generated by the watermark information generating unit to the image. Claim 11 A watermark generating device according to claim 10, wherein the watermark output unit outputs the watermark to the target area. Claim 12 A watermark generating device according to claim 11, wherein the watermark output unit outputs the watermark to the image such that the number of frames appearing during one second of the image is proportional to the number of colors included in the color combination of the watermark.

Images