Image projector, and method for controlling same

Abstract

Disclosed are an image projector and a method for controlling same. An image projector according to an embodiment of the present invention may comprise: a projection unit for forming a white pattern and outputting the white pattern onto a projection surface; and a processor which generates a map representing chromaticity and luminance on the basis of the RGB values of each pixel of an image taken of the projection surface, detects the position of external light on the basis of the map, generates a plurality of color patches, each including a plurality of colors, on the basis of the position of the external light and arranges the plurality of color patches on the projection surface, corrects the chromaticity and luminance of remaining color patches on the basis of the chromaticity and luminance of a color patch selected through a user interface, and corrects the chromaticity and luminance of an RGB output image on the basis of the correction values.

Description

Video projector and method for controlling the same

[0001] The disclosed invention relates to a video projector and a method for controlling the same.

[0002] An image projector can project images in any direction and location specified by the user. An image projector can project image data stored in memory or image signals input to an image input terminal onto a screen or wall.

[0003] The color of an image projected by a video projector can be affected by, for example, the brightness of an external light source (also known as ambient light). Such projection environments can degrade image quality.

[0004] These problems can be exacerbated in portable video projectors, so image quality improvement that takes outdoor lighting conditions into account is necessary.

[0005] However, it has been very difficult for general users without specialized knowledge to operate a video projector to achieve high image quality with uniformity according to external lighting conditions.

[0006] The disclosed invention provides an image projector capable of providing high uniform image quality by taking external light conditions into consideration, and a method for controlling the same.

[0007] An image projector according to one aspect of the disclosed invention may include a projection unit that forms a white pattern and outputs it to a projection surface; and a processor that generates a map representing chromaticity and luminance based on the RGB values ​​of each pixel of an image photographed on the projection surface, detects a location of external light based on the map, generates a plurality of color patches each including a plurality of colors based on the locations of the external light, and arranges the color patches on the projection surface, performs correction for the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of a color patch selected through a user interface, and corrects the chromaticity and luminance of an RGB output image based on the correction value.

[0008] It may further include a sensor unit that photographs the projection surface and generates an image.

[0009] The above processor can calculate a relative value by dividing the color and luminance of each pixel of the captured image by the average value of the color and luminance of the entire image, and generate the map based on the relative value.

[0010] The processor can detect the location of the external light by recognizing at least one of a color change and a brightness change of the image based on the map.

[0011] The processor can generate the plurality of color patches based on at least one of brightness, contrast, and color temperature according to the location of the external light.

[0012] The above processor can place one color patch in the center of the projection surface and two color patches in the upper and lower areas on each side of the projection surface.

[0013] The above processor can generate the plurality of color patches, each having a plurality of color cells.

[0014] The above processor can perform correction on the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell when a color patch having a color cell closest to white is selected by the user through the user interface.

[0015] A method for controlling an image projector according to another aspect may include forming a white pattern and outputting it to a projection surface, generating a map representing chromaticity and luminance based on the RGB values ​​of each pixel of an image photographed on the projection surface, detecting a position of external light based on the map, generating a plurality of color patches each including a plurality of colors based on the positions of the external light, and arranging the color patches on the projection surface, performing correction for the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of a color patch selected through a user interface, and correcting the chromaticity and luminance of an RGB output image based on the corrected values.

[0016] Generating the above map includes calculating a relative value by dividing the color and luminance of each pixel of the captured image by the average value of the color and luminance of the entire image, and the map can be generated based on the relative value.

[0017] Detecting the location of the external light includes recognizing at least one of a color change and a brightness change of the image based on the map, and detecting the location of the external light based on the recognition result.

[0018] The plurality of color patches may be generated based on at least one of brightness, contrast, and color temperature according to the position of the external light.

[0019] Generating the plurality of color patches and placing them on the projection surface may include placing one color patch in the center of the projection surface and two color patches in the upper and lower areas on each side of the projection surface.

[0020] The above plurality of color patches can be generated so that each has a plurality of color cells.

[0021] When a color patch having a color cell closest to white is selected by the user through the above user interface, correction can be made for the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell.

[0022] In another aspect, a computer-readable recording medium can store one or more programs including commands for performing a method of controlling an image projector.

[0023] The disclosed video projector and its control method can provide highly uniform image quality by taking external light conditions into consideration.

[0024] A user interface can be used to allow a user to easily select a color patch, and the chromaticity and luminance of an RGB output image can be corrected based on the correction value of the color patch to ensure uniform image quality.

[0025] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0026] Figure 1 is a block diagram showing components of an image projector according to one embodiment.

[0027] Figure 2 illustrates color patches arranged on a projection surface according to one embodiment.

[0028] Figure 3 is a flowchart illustrating a method for controlling a video projector according to one embodiment.

[0029] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0030] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0031] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0032] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0033] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0034] The terms "part," "module," and "member" may be implemented in hardware or software. Depending on the embodiments, multiple "parts," "modules," or "members" may be implemented as a single component, or a single "part," "module," or "member" may include multiple components.

[0035] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0036] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0037] The terms "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0038] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0039] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0040] Below, displays according to various embodiments are specifically described with reference to the attached drawings.

[0041] Figure 1 is a block diagram showing components of an image projector according to one embodiment.

[0042] Referring to FIG. 1, the image projector (100) may include a projection unit (110), a sensor unit (120), a user interface (130), a processor (140), and a memory (150). Without being limited thereto, the image projector (100) may include various known elements, such as a means for receiving audio and image signals by being connected to an external device, a power supply means, and a projector driving means, although not illustrated. The image projector (100) may include, for example, a DLP (Digital Light Processing) projector, an LCD projector, and the like.

[0043] The projection unit (110) can form a white pattern and output it to the projection surface (screen). That is, the projection unit (110) can form a white pattern using RGB white signals (255, 255, 255) and evenly project it onto the projection surface.

[0044] The projection unit (110) may include a lamp that generates white light and a digital mirror device (DMD, Digital Micromirror Device) or display panel that uses the light from the lamp to form a white pattern or color image. The digital mirror device may be used in a DLP projector, and the display panel may be used in an LCD projector.

[0045] The sensor unit (120) captures the projection surface and generates an image. The sensor unit (120) may include, for example, a camera of an image projector (100).

[0046] The sensor unit (120) can obtain information on color and brightness by analyzing the RGB values ​​of each pixel of the image. The sensor unit (120) can be included in a processor (140) to be described later.

[0047] The sensor unit (120) may use CCD (Charge-Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor) technology. In another example, the projection surface may be captured using another camera connected to the image projector (100).

[0048] In addition, the sensor unit (120) may include at least one of a light sensor that detects the brightness and intensity of ambient external light (external light source), a color sensor that detects the color of the external light, and an image sensor that detects the chromaticity and luminance of a captured image.

[0049] The user interface (130) may be provided in various forms, such as buttons or selection screens. For example, when a plurality of color patches (Color Patches) described later are arranged on a projection surface, the user interface (130) may enable the user to select a desired color patch from among the color patches.

[0050] Additionally, the user interface (130) may enable, for example, turning the video projector (100) on and off, selecting a source to project from among various input sources (e.g., computer, laptop, DVD player, etc.), changing various settings, etc.

[0051] The processor (140) can control the overall operation and function of the image projector (100), and the functions of the image projector (100) can be processed by one processor (140) or performed by a combination of multiple processors (140).

[0052] The processor (140) may be implemented as a digital signal processor (DSP), a microprocessor, or the like. However, the present invention is not limited thereto, and may include at least one of a central processing unit (CPU), a micro controller unit (MCU), a micro processing unit (MPU), a controller, an application processor (AP), a communication processor (CP), or an ARM processor, or may be defined by the terms thereof. In addition, the processor (140) may be implemented in the form of a system on chip (SoC), a large scale integration (LSI), or a field programmable gate array (FPGA) having a built-in processing algorithm.

[0053] The processor (140) may include logic circuits and arithmetic circuits as hardware. The processor (140) may control electrically connected components of the image projector (100) using programs, instructions, and data stored in the memory (150) for the operation of the image projector (100). The processor (140) and the memory (150) may be implemented as separate chips or as a single chip.

[0054] The processor (140) can generate a map representing color and brightness based on the RGB values ​​of each pixel of the image captured by the sensor unit (120) described above.

[0055] A map can represent the color of each pixel in an image as coordinates in a specific color space, allowing for quantitative determination of the chromaticity of each pixel. Furthermore, a map can provide brightness information for each pixel in an image.

[0056] The processor (140) can analyze the RGB values ​​of each pixel of the image by the sensor unit (120) to obtain color and luminance information and create a map based on this.

[0057] Here, the processor (140) can calculate a relative value by dividing the color and luminance of each pixel of the image photographed on the projection surface by the average value of the color and luminance of the entire image, and can create a map based on the calculated relative value.

[0058] The processor (140) can detect the location of external light based on the map. Areas in the image close to the location of external light can have relatively high chromaticity and luminance.

[0059] The processor (140) can detect the location of external light by recognizing at least one of color change and brightness change of an image based on a map. By detecting the location of external light, the direction of the external light can be naturally determined. In other words, the direction from which the external light is emitted can be determined.

[0060] In addition, the processor (140) can generate a plurality of color patches, each containing a plurality of colors, based on the position of the external light described above, and place them on the projection surface.

[0061] Here, the processor (140) can generate a plurality of color patches based on at least one of brightness, contrast, and color temperature according to the location of external light.

[0062] Figure 2 illustrates color patches arranged on a projection surface according to one embodiment.

[0063] Referring to FIG. 2, the processor (140) can generate a plurality of color patches (105a to 105e) including a plurality of color cells (104). For example, the processor (140) can generate a plurality of color patches (105a to 105e) each having 12 color cells (104).

[0064] The color cells (104) of each color patch (105a to 105e) can be arranged in the same number and have the same rows and columns.

[0065] The color set in each color cell (104) can be selected by taking into account changes in the color temperature of external light, etc.

[0066] Each color cell (104) can have a different tone of color, and the arrangement order of the color cells (104) can be the same for each color patch (105a to 105e).

[0067] Each color cell (104) may have a variety of colors, such as white (also called white), red, and green, so that the influence of external light can be estimated in various shades. Each color cell (104) may be formed in the shape of a square box, for example, and arranged at set intervals.

[0068] The processor (140) can, for example, place five color patches (105a to 105e) on the projection surface. Specifically, the processor (140) can place one color patch (105e) in the center of the projection surface and two color patches (105a to 105d) in the upper and lower areas on each side of the projection surface.

[0069] The color patch (105e) placed in the central area of ​​the projection surface is located at the center of the projection surface, so it can be usefully used to correct the balance between the dark and bright parts of the image quality.

[0070] Color patches (105a to 105d) arranged in the upper and lower areas on both sides of the projection surface can be usefully utilized to correct color distortion occurring on the side of the projection surface.

[0071] In this way, the color patch (105e) positioned in the center of the projection surface and the color patches (105a to 105d) positioned in the upper and lower areas on both sides are exposed to different external light conditions, and thus can be effectively utilized to correct for uniformly high image quality in various areas of the projection surface.

[0072] For example, if external light is located at the lower right of the projection surface, each color patch (105a to 105e) may have different chromaticity and luminance. To provide high-quality image quality, the five color patches (105a to 105e) must have uniform chromaticity and luminance.

[0073] Accordingly, the processor (140) can correct the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the color patch selected through the user interface (130), and can correct the chromaticity and luminance of the RGB output image based on the correction value of the color patch.

[0074] When correcting an RGB output image, the processor (140) can perform correction according to the optical characteristics of the image projector (100). For example, the processor (140) can perform correction of an RGB output image considering the distortion coefficient, focal length, etc. of the lens of the image projector (100) to provide an optimal visual effect to the user.

[0075] When a color patch having a color cell closest to white is selected by a user through the user interface (130), the processor (140) can perform correction on the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell of the color patch.

[0076] For example, if a user selects a color patch (105b) in the upper left area as the color patch with the color cell closest to white through the user interface (130), correction can be made for the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell (102) of the color patch (105b).

[0077] The user can repeatedly select a color patch with cells closest to white according to his / her judgment through the user interface (130), and correction of the remaining color patches can be performed to match the white tone of the color patch.

[0078] In another example, the processor (140) may automatically select a color patch positioned in an area closest to the location of the external light on the projection surface, and perform corrections for the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell of the color patch.

[0079] The memory (150) can store programs, applications, and data for the operation of the video projector (100), and can store data generated by the processor (140).

[0080] The memory (150) can store information about an image captured by the sensor unit (120), information detected by the sensor unit (120), information related to the position and direction of external light, map information, RGB values ​​of each pixel of the image, chromaticity and luminance information of the image, information related to color patches, color coordinate correction, etc.

[0081] The memory (150) may include non-volatile memory such as ROM (Read Only Memory) and flash memory for long-term storage of data. The memory may include volatile memory such as S-RAM (Static Random Access Memory) and D-RAM (Dynamic Random Access Memory) for temporarily storing data.

[0082] Figure 3 is a flowchart illustrating a method for controlling a video projector according to one embodiment.

[0083] Referring to Fig. 3, the projection unit (110) forms a white pattern and outputs it to the projection surface (301).

[0084] Here, the projection unit (110) can form a white pattern using RGB white signals (255, 255, 255) and project it evenly onto the projection surface.

[0085] The processor (140) generates a map representing color and luminance based on the RGB values ​​of each pixel of the image photographed on the projection surface (311).

[0086] Here, the color and luminance of each pixel of the captured image can be divided by the average value of the color and luminance of the entire image to calculate a relative value, and a map can be created based on the relative value.

[0087] The processor (140) detects the location of external light based on the map, and generates a plurality of color patches, each containing a plurality of colors, based on the location of the external light, and places them on the projection surface (331).

[0088] Here, detecting the location of the external light includes recognizing at least one of a color change and a brightness change of the image based on the map, and the location of the external light can be detected based on the recognition result.

[0089] And, the plurality of color patches can be generated based on at least one of brightness, contrast, and color temperature according to the position of the external light.

[0090] Multiple color patches can be generated, each having multiple color cells.

[0091] Additionally, generating multiple color patches and placing them on the projection surface may include placing one color patch in the center of the projection surface and two color patches in the upper and lower areas on each side of the projection surface.

[0092] The processor (140) performs correction for the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the color patch selected through the user interface (130) (331).

[0093] Here, when a color patch having a color cell closest to white is selected by the user through the user interface (130), correction can be made for the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell.

[0094] The processor (140) corrects the chromaticity and luminance of the RGB output image based on the above-described correction values ​​(341).

[0095] That is, the processor (140) can correct the chromaticity and luminance of the RGB output image based on the correction value of the color patch. When correcting the RGB output image, the correction can be performed according to the optical characteristics of the image projector (100). For example, the processor (140) can perform correction of the RGB output image considering the distortion coefficient, focal length, etc. of the lens of the image projector (100) to provide an optimal visual effect to the user.

[0096] In this way, the above-described embodiment allows a user to easily select a color patch through a user interface, and corrects the chromaticity and luminance of an RGB output image based on the correction value of the color patch, thereby providing a uniform image quality.

[0097] The methods according to various embodiments disclosed in this document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store (e.g., Play Store™) or directly between multiple user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0098] The above illustrates and describes specific embodiments. However, the present invention is not limited to the aforementioned embodiments, and those skilled in the art will appreciate that various modifications and implementations can be made without departing from the spirit and scope of the invention as set forth in the claims below.

Claims

1. A projection unit that forms a white pattern and outputs it to the projection surface; and An image projector comprising a processor that generates a map representing color and luminance based on the RGB values of each pixel of an image photographed on the projection surface, detects the location of external light based on the map, generates a plurality of color patches each including a plurality of colors based on the location of the external light, places them on the projection surface, performs correction for the color and luminance of the remaining color patches based on the chromaticity and luminance of the color patch selected through a user interface, and corrects the color and luminance of the RGB output image based on the correction value.

2. In paragraph 1, An image projector further comprising a sensor unit that photographs the projection surface and generates an image.

3. In paragraph 1, The above processor, The relative value is calculated by dividing the color and luminance of each pixel of the above-mentioned captured image by the average value of the color and luminance of the entire image, An image projector that generates the map based on the above relative values.

4. In paragraph 1, The above processor, An image projector that detects the location of the external light by recognizing at least one of a color change and a brightness change of the image based on the map.

5. In paragraph 4, The above processor, An image projector that generates the plurality of color patches based on at least one of brightness, contrast, and color temperature according to the position of the external light.

6. In paragraph 5, The above processor, A video projector that places one color patch in the center of the projection surface and two color patches in the upper and lower areas on each side of the projection surface.

7. In paragraph 5, The above processor, An image projector that generates the plurality of color patches, each having a plurality of color cells.

8. In paragraph 7, The above processor, An image projector that, when a color patch having a color cell closest to white is selected by a user through the above user interface, corrects the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell.

9. Create a white pattern and print it on the projection surface. Generate a map representing color and luminance based on the RGB values of each pixel of the image captured on the projection surface, Detect the location of external light based on the above map, Based on the location of the above external light, a plurality of color patches each containing a plurality of colors are generated and placed on the projection surface, Corrects the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the color patch selected through the user interface, A control method for an image projector that corrects the color and luminance of an RGB output image based on the above-mentioned corrected values.

10. In paragraph 9, Creating the above map is: It includes calculating a relative value by dividing the color and luminance of each pixel of the above-mentioned captured image by the average value of the color and luminance of the entire image, A method for controlling an image projector that generates the map based on the above relative values.

11. In paragraph 9, Detecting the location of the above external light is, Recognizing at least one of a color change and a brightness change of the image based on the map, A control method for an image projector that detects the position of the external light based on the above-described recognition result.

12. In paragraph 11, A control method for an image projector in which the plurality of color patches are generated based on at least one of brightness, contrast, and color temperature according to the position of the external light.

13. In paragraph 12, Generating the above plurality of color patches and placing them on the projection surface, A method for controlling an image projector, comprising placing one color patch in the center of the projection surface and two color patches in the upper and lower areas on each side of the projection surface.

14. In paragraph 12, A method for controlling an image projector, wherein each of the plurality of color patches is generated to have a plurality of color cells.

15. In paragraph 14, A control method for an image projector, wherein when a color patch having a color cell closest to white is selected by a user through the above user interface, correction is made to the chromaticity and luminance of the remaining color patches based on the chromaticity and luminance of the white color cell.

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