Apparatus for generating invisible watermark

Abstract

An apparatus for generating a watermark in an image, according to an embodiment of the present disclosure, comprises: an image recognition unit that recognizes an image for a specific area of the image; an image analysis unit that extracts colors from the image for the specific area; and a watermark information generation unit that generates the watermark, wherein the image analysis unit matches a target color having a maximum number from among colors extracted from the image for the specific area, and the color of the watermark may be obtained from a combination of a plurality of colors to correspond to the target color.

Description

Invisible watermark generator

[0001] The present disclosure relates to a watermark generating device, and more specifically, to a device for generating a watermark that is invisible to the human eye on a screen displayed on an image, but visible in an image captured from the image.

[0002] As semiconductor circuits become smaller and high-density integrated circuit technologies advance, camera modules capable of capturing images of objects are now embedded in even small smartphones, replacing traditional cameras. Individuals can easily carry small smartphones for personal use and capture images of desired objects. Furthermore, it's becoming commonplace to utilize ICT technology for work within the company. Typically, employees within the company acquire and process information using the display screens of desktop or laptop monitors. In this case, individuals can easily access and capture protected data displayed on the display screen, making it easy for them to capture and possess this data. For example, this risk extends beyond individuals attempting to capture confidential data. Furthermore, there are also cases where confidential data stored on smartphones is compromised through hacking or other means. While the former scenario makes it relatively easy to trace the source of the leak, the latter scenario presents significant challenges. In addition, if a watermark that can identify an individual is additionally displayed on the display screen to identify leak routes of security data, it may interfere with other textures on the display, thereby reducing work efficiency.

[0003] The present disclosure has been made in response to the aforementioned background technology, and has as its primary purpose the provision of a watermark generation device capable of efficiently displaying a watermark on a captured image.

[0004] In addition, the present disclosure aims to provide a device for generating a watermark that is invisible to the eyes of a person viewing the display screen, but is visible in an image captured by the display screen.

[0005] The purpose is to provide security technology that utilizes the difference between the human eye, which perceives objects slowly, and the camera, which takes pictures relatively quickly.

[0006] However, the problems to be solved in the present disclosure are not limited to the problems described above, and problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure pertains from this specification and the attached drawings.

[0007] A watermark generating device according to one embodiment of the present disclosure for realizing the task described above is disclosed. The device for generating a watermark in an image according to one embodiment includes an image recognition unit for recognizing an image of a specific area of ​​an image, an image analysis unit for extracting a color from the image of the specific area, and a watermark information generating unit for generating the watermark, wherein the image analysis unit matches a target color having the maximum number of colors extracted from the image of the specific area, and the color of the watermark may be a combination of a plurality of colors and correspond to the target color.

[0008] Alternatively, the watermark may be 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 to the same area of ​​the specific area.

[0009] Alternatively, the first watermark may be output to the image at odd times during which a frame appears for 1 second of the image, and the second watermark may be output to the image at even times during which a frame appears for 1 second of the image.

[0010] Alternatively, the first color combination and the second color combination may be repeatedly output to the specific area so that the first color combination and the second color combination overlap and are recognized as the target color by the human eye.

[0011] Alternatively, the watermark may be 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.

[0012] Alternatively, the first watermark, the second watermark, and the third watermark may be output alternately to the same area of ​​the specific area, and the first watermark may be output to the image N times (N is a natural number) in which a frame appears for 1 second of the image, the second watermark may be output to the image N+1 times in which a frame appears for 1 second of the image, and the third watermark may be output to the image N+2 times in which a frame appears for 1 second of the image.

[0013] Alternatively, the watermark may be combined with colors consisting of natural numbers of 4 or more.

[0014] Alternatively, the image analysis unit can calculate the maximum area formed by adjacent unit blocks having the target color within the specific area.

[0015] Alternatively, the image analysis unit may set the maximum area as a target area where the watermark is to be output.

[0016] Alternatively, the watermark information generating unit may further include a watermark output unit that outputs the watermark generated by the watermark information generating unit to the image.

[0017] Alternatively, the watermark output unit can output the watermark to the target area.

[0018] Alternatively, the watermark output unit may output the watermark to the image such that the number of frames appearing in one second of the image is proportional to the number of colors included in the color combination of the watermark.

[0019] According to one embodiment of the present disclosure, a watermark can be efficiently displayed on a captured image.

[0020] Additionally, according to one embodiment of the present disclosure, a watermark that is invisible to the eyes of a person viewing the display screen, but visible in an image captured of the display screen, can be generated.

[0021] Additionally, according to one embodiment of the present disclosure, security can be enhanced without reducing work efficiency.

[0022] The effects of the present disclosure are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from this specification and the attached drawings.

[0023] FIG. 1 is a schematic diagram schematically showing a watermark generating device and an image displaying device according to one embodiment of the present disclosure.

[0024] Fig. 2 is a block diagram schematically showing the watermark generation device of Fig. 1.

[0025] Figures 3 to 5 are schematic diagrams for sequentially explaining the mechanism by which the watermark generation device of Figure 1 generates and outputs a watermark on an image.

[0026] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings so that those skilled in the art can easily practice the present disclosure. The embodiments of the present disclosure may be modified and implemented in various forms and are not limited to the embodiments described below. In addition, the embodiments described below are provided so that those skilled in the art can more completely explain the present disclosure. Therefore, the shapes of components in the drawings are exaggerated to emphasize clear explanation. In addition, when describing the preferred embodiments of the present disclosure in detail, if it is determined that a specific description of a related known function or configuration may unnecessarily dilute the gist of the present disclosure, a detailed description thereof will be omitted. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and operations.

[0027] To "include" a component, unless otherwise specifically stated, does not exclude other components, but rather implies that other components may be included. Specifically, terms such as "include" or "have" should be understood to mean features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] Singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "first" and "second" may be used to describe various components, but these components are not limited by these terms. These terms may be used to distinguish one component from another. For example, within the scope of the present disclosure, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component."

[0029] In context, the expression 'less than' can be used to mean 'less than', and the expression 'more than' can be understood to be used to mean 'exceeding'.

[0030] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted in a way consistent with their meaning within the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined below.

[0031] 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.

[0032] Here, the term "image" can be defined as a general term for an image displayed on a screen, regardless of the type of screen. For example, in the present disclosure, the term "image" may be an image displayed on a desktop monitor screen, an image displayed on a mobile (including PDP, cell phone, etc.) screen, or an image displayed on a portable laptop monitor screen. Furthermore, the term "image" is not limited to the type of display device, such as an LCD (Liquid Crystal Display), a PDP (Plasma Display Panel), or an OLED (Organic Light Emitting Diodes). In addition, the watermark of the present disclosure may be displayed on an image for each frame generated by the display. For example, if 60 frames are displayed on the screen of a display for 1 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 for 1 second.

[0033] Here, a watermark can be defined as a combination of shapes, characters, and / or numeric strings displayed for security purposes. For example, the watermark may be the employee number of a specific person working in the company. In addition, the watermark of the present disclosure may be of a size that is identifiable to the human eye. However, the interpretation is not limited thereto, and the watermark of the present disclosure should be understood as a concept that includes all means for identifying a specific person. In addition, the watermark of the present disclosure may have a color 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 RGB three colors. In the present disclosure, the RGB color model is used as an example, but the present disclosure is not limited thereto, and various color models such as CMY and HSV may be used.

[0034] Hereinafter, a watermark generating device according to one embodiment of the present disclosure will be described in detail with reference to the attached drawings.

[0035]

[0036] FIG. 1 is a schematic diagram schematically showing a watermark generating device and an image displaying device according to one embodiment of the present disclosure. FIG. 2 is a block diagram schematically showing the watermark generating device of FIG. 1. FIGS. 3 to 5 are schematic diagrams sequentially explaining the mechanism by which the watermark generating device of FIG. 1 generates and outputs a watermark on an image.

[0037]

[0038] As illustrated in FIG. 1, a watermark generating device (100) according to one embodiment is connected to a display (10). The type of the display (10) is not limited as described above. In addition, the watermark generating device (100) may be connected wirelessly to the display (10). Furthermore, the watermark generating device (100) may also be connected to the display (10) by wire. In addition, instead of being directly connected to the display (10), the watermark generating device (100) may be connected wirelessly or by wire to a video card, a graphics card, or other OS (SW) driving driver that outputs a screen to the display (10). In another embodiment, the watermark generating device (100) may be installed as a firmware in an OS (SW) driving driver, and a watermark may be generated and output on an image of the display (10) by executing the firmware.

[0039]

[0040] As illustrated in FIG. 2, a watermark generation 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 generation unit (130), and a watermark output unit (140).

[0041] In one embodiment, the image recognition unit (110) recognizes an image of an image currently displayed on the display (10). Specifically, the image recognition unit (110) can recognize an image of a specific area of ​​the image. The specific area may mean the entire area of ​​the image displayed on the display (10) or an area of ​​a portion of the entire area of ​​the image.

[0042] For example, as illustrated in FIG. 3, the image recognition unit (110) can divide the entire area of ​​the image displayed on the display (10) into four areas and recognize one area (e.g., the upper right area) among them as a specific area (MA). However, this is merely an example for convenience of understanding, and the present disclosure is not limited thereto.

[0043] In addition, the image recognition unit (110) can acquire an image for a specific area (MA) by dividing it into unit blocks. A unit block may refer to a block having a set horizontal and vertical size. For example, a unit block may have a size of 1 pixel, but this is merely exemplary. Accordingly, the image recognition unit (110) can acquire at least one unit block image for the specific area (MA).

[0044] In one embodiment, the image analysis unit (120) receives an image for a specific area (MA) recognized by the image recognition unit (110). As described above, the image recognition unit (110) can obtain an image for the specific area (MA) by dividing it into unit blocks, and therefore, the image analysis unit (120) can also receive at least one unit block image included in the specific area (MA) from the image recognition unit (110).

[0045] The image analysis unit (120) extracts colors from the image for the received specific area (MA). Specifically, the image analysis unit (120) distinguishes and individually extracts the colors of each of the unit block images included in the specific area (MA). For example, as illustrated in FIG. 3, among the colors of the unit block images within the specific area (MA), approximately 90% may be extracted as yellow, approximately 8% as gray, and approximately 2% as white. In this case, the image analysis unit (120) may extract the predominant color from the image for the specific area (MA) as yellow, and match the color as the target color. That is, the image analysis unit (120) matches the color with the largest number of colors among the colors extracted from the image for 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, a color with the next highest number of colors can be matched as the target color.

[0046] In addition, the image analysis unit (120) evaluates the adjacency of unit blocks having a color matched to the target color within the received specific area (MA). Specifically, the image analysis unit (120) calculates 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 compares and evaluates the sizes of each area (A1, A2, TA) with each other. The image analysis unit (120) sets the area having the largest 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 secure the area where the watermark will be output as much as possible. This is because, although desktop displays often have a sufficient area for displaying a watermark, displays of small devices such as mobile devices often do not have a sufficient area for displaying a watermark. Therefore, the present disclosure can be effectively applied to displays of small devices.

[0047] A watermark information generation unit (130) according to one embodiment generates a watermark on an image. The watermark generated by the watermark information generation unit (130) may have a predetermined 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. For convenience of explanation, the following description will be made using an example in which the watermark according to one embodiment is the English letter "S" as illustrated in FIG. 4.

[0048] The watermark information generation unit (130) generates M or more watermarks (M is a natural number greater than or equal to 2). In addition, 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). In one example, the first watermark (WM1) can have a first color combination, and the second watermark (WM2) can have a second color combination. The color combinations constituting each watermark can be different from each other. In addition, the color combinations constituting each watermark can have a symmetrical structure. In addition, the color combinations constituting each watermark can have the same kind of color. That is, each color combination constituting each watermark can have a structure in which the same colors are arranged symmetrically (or alternately) with each other.

[0049] 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 the center line passing through the upper and lower portions of the English letter "S." In addition, the second color combination of the second watermark (WM1) may be green on the left side and red on the right side, based on the center line passing through the upper and lower portions of the English letter "S." In this example, the center line passing through the upper and lower portions is used as the reference, but it is not limited thereto, and it is obvious that the color division and color combination may be freely modified within a range that can be easily changed by those skilled in the art.

[0050] In one embodiment, the watermark output unit (140) outputs the watermarks (WM1, WM2) generated by the watermark information generation unit (130) to the target area (TA) described above. 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 that the screen refresh rate of the display is 60 Hz, the first watermark (WM1) can be output on the display (10) image at odd times that 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 that the image appears in the frame for 1 second. In other words, the first watermark (WM1) and the second watermark (WM2) can be output at the same location within the target area (TA) by alternately switching 30 times each for 1 second.

[0051] Accordingly, the first watermark (WM1) and the second watermark (WM2) are output to the image of the display (10) as shown in FIG. 4(a), but the watermark (WM) in which the first watermark (WM1) and the second watermark (WM2) are overlapped is recognized by the eyes of the person viewing the image due to the difference in speed between the organ that receives light and the organ that transmits it as shown in FIG. 4(b) (in FIG. 4(b), the outline of the watermark (WM) is indicated by a dotted line for ease of understanding, but the outline dotted line is not visible to the eyes of the person). That is, due to the flicker principle, the target color of the target area (TA) and the color of the watermark (WM) recognized by the eyes of the person become the same. As a result, the watermark (WM) in which the first watermark (WM1) and the second watermark (WM2) are overlapped are not visible to the eyes 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) output to the target area (TA) of the image is displayed on the captured image.

[0052] According to the embodiments of the present disclosure described above, a watermark can be clearly displayed in an image captured while remaining invisible to the human eye. This effectively enhances image security without compromising the efficiency of workers viewing and working with the image.

[0053]

[0054] In the above example, the watermark information generation unit (130) generates two watermarks (i.e., a combination of two colors), but the present invention is not limited thereto. For example, the watermark information generation unit (130) may generate a first watermark, a second watermark, and a third watermark, respectively, and the first watermark may be formed of a first color combination, the second watermark may be formed of a second color combination, and the third watermark may be formed 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 vertically divided into three. At this time, the first color combination may be a combination of red on the left, green in the center, and blue on the right, the second color combination may be a combination of green on the left, blue in the center, and red on the right, and the third color combination may be a combination of blue on the left, red in the center, and green on the right. In addition, the first watermark may be output to the image N times (N is a natural number) that appear in the frame for 1 second of the image, the second watermark may be output to the image N+1 times that appear in the frame for 1 second, and the third watermark may be output to the image N+2 times that appear in the frame for 1 second. That is, the first watermark, the second watermark, and the third watermark may be switched and output at the same position on the image. Accordingly, the final color of the watermark displayed on the image may be recognized by the human eye as white, which is the same as the target color of the target area.

[0055] It goes without saying that the above mechanism can be equally applied even when the watermark generated by the watermark information generation unit (130) is output on an image by combining four or more colors. In addition, the number of frames that appear on the image of the display for one second can be proportional to the number of colors that the watermark generated by the watermark information generation unit (130) has. For example, if the number of colors that the watermark has is two, the screen refresh rate of the display can be 120 Hz, and if the number of colors that the watermark has is three, the display screen refresh rate can be 180 Hz. In the present disclosure, the screen refresh rate is described based on a multiple of 60 as an example, but is not limited thereto, and the standard screen refresh rate can be set in various ranges other than 60 Hz, and the screen refresh rate of the display can be set in proportion to the number of colors that the watermark has and the standard screen refresh rate. If the range of the screen refresh rates that can be set for the display is fixed, the number of colors that the watermark can have can be determined according to the screen refresh rate.

[0056]

[0057] In addition, in addition to the above-described embodiment, the watermark generation device (100) of the present disclosure can preemptively compare the brightness of the image within the specific area (MA) before extracting the color from the image for the specific area (MA) received from the image analysis unit (120). That is, the image analysis unit (120) can adaptively determine whether there are many dark pixels or many white pixels, compare the numbers thereof, and select an optimal area within the specific area (MA) as the target area (TA). For example, an area in which the watermark is well displayed in the captured image while being relatively unobtrusive to the human eye depending on the color or brightness within the image can be selected as the target area (TA).

[0058]

[0059] In addition to the above-described embodiments, 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 wide, so the pattern of the watermark to be output on the image can be varied, and the watermark can be generated and output in a relatively large size. In contrast, in the case of a mobile screen, since the overall image size is relatively small, it is relatively difficult to secure the output location of the watermark. In this case, the pattern of the watermark to be output on the image can be simplified, and the watermark can be generated and output in a relatively small size. Furthermore, the watermark generating device (100) of the present disclosure can output the generated watermark even in an area of ​​the display image where letters are displayed, in order to make it difficult for a specific person to arbitrarily edit an image captured by a specific person. In addition, watermarks having different patterns, letters, and shapes can be generated, and these can be output in the areas (A1, A2, TA) described with reference to FIG. 3, respectively. For example, a watermark consisting of an affiliation can be output in one area (A1), a watermark consisting of a position can be output in another area (A2), and a watermark consisting of an employee number can be output in yet another area (TA).

[0060]

[0061] The detailed description above is illustrative of the present disclosure. Furthermore, the above description illustrates and describes preferred embodiments of the present disclosure, and the present disclosure can be used in various other combinations, modifications, and environments. In other words, changes or modifications are possible within the scope of the concept of the present disclosure, the scope equivalent to the disclosed disclosure, and / or the scope of technology or knowledge in the art. The described embodiments illustrate the best possible state for implementing the technical idea of ​​the present disclosure, and various modifications required for specific applications and uses of the present disclosure are also possible. Therefore, the detailed description of the invention above is not intended to limit the present disclosure to the disclosed embodiments. Furthermore, the appended claims should be construed to include other embodiments.

Claims

1. A device that creates a watermark on an image. An image recognition unit that recognizes an image of a specific area of ​​an image; An image analysis unit for extracting colors from an image for the above specific area; and Including a watermark information generation unit that generates the above watermark, The above image analysis unit matches the target color with the maximum number of colors extracted from the image for the specific area, A watermark generating device, characterized in that the color of the watermark is a combination of multiple colors and corresponds to the target color.

2. In paragraph 1, The above watermark is, It 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, A watermark generating device characterized in that the first watermark and the second watermark are repeatedly output to the same area of ​​the specific area.

3. In paragraph 2, The above first watermark is output to the image at odd times when the frame appears for 1 second of the image, A watermark generating device characterized in that the second watermark is output to the image at even number of times during which a frame of the image appears for 1 second.

4. In paragraph 3, A watermark generating device 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 and are recognized as the target color by the human eye.

5. In paragraph 1, The above watermark is, It 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. A watermark generating device, characterized in that the first color combination, the second color combination, and the third color combination are different from each other.

6. In paragraph 5, The above first watermark, the above second watermark and the above third watermark are output alternately in the same area of ​​the specific area, The above first watermark is output to the image N times (N is a natural number) when the frame appears for 1 second of the image, The above second watermark is output to the image at N+1 times when the frame appears for 1 second of the image, A watermark generating device characterized in that the third watermark is output to the image N+2 times during which a frame of the image appears for 1 second.

7. In paragraph 1, A watermark generating device characterized in that the above watermark is composed of colors consisting of natural numbers of 4 or more.

8. In any one of paragraphs 1 to 7, The above image analysis unit, A watermark generating device characterized by calculating the maximum area formed by adjacent unit blocks having the target color within the specific area.

9. In paragraph 8, The above image analysis unit, A watermark generating device characterized in that the above maximum area is set as a target area where the watermark is to be output.

10. In paragraph 9, A watermark generation device further comprising a watermark output unit that outputs the watermark generated by the watermark information generation unit to the image.

11. In paragraph 10, The above watermark output section, A watermark generating device characterized by outputting the watermark to the target area.

12. In paragraph 11, The above watermark output section, A watermark generating device characterized in that it outputs the watermark to the image so that the number of frames appearing for 1 second of the image is proportional to the number of colors included in the color combination of the watermark.

Images