JP5455506B2 - Image display device - Google Patents

Description

  The present invention relates to an image display device, and more specifically to an image display device capable of controlling correction for ambient light in accordance with image content.

Japanese Patent No. 3854678 JP 2001-060082 A

  Conventionally, a color management system has attracted attention as means for correcting an image according to ambient light. The color management system tries to eliminate the color difference between devices by using a common color space, and the same coordinate color in the same color space should look the same color visually. based on. By expressing all colors in the same color space and matching the corresponding coordinates, the appearance of the colors can be matched.

  For example, a method is known in which a CIE-XYZ color space is used as a color space, and XYZ tristimulus values that are internal description coordinate values are used to correct differences between devices. With this technology, the color of an image can be faithfully reproduced under any ambient light.

  Japanese Patent Application Laid-Open No. 2005-228561 describes a technique for obtaining a printed material that looks the same color on the receiving side in a system that transmits image data from the transmitting side to the receiving side via a network. Specifically, the transmission side transmits the transmission side observation light information and the profile information of the input device to the reception side together with the image data. The reception side generates a printed material that is color-reproduced so as to be seen in the same color as that seen with the transmission side observation light from the reception information, the profile information of the output device, and the reception side observation light information.

  Patent Document 2 describes a technology for providing an illumination light sensor or a sensor for confirming the color reproducibility of a display device and stabilizing the appearance color of a display image in accordance with observation results of photographing environment light and light around the display. ing. Further, the reproduction color is corrected by transmitting the illumination light information through the network, downloading the color conversion program from the color reproduction server, and applying it. If this technology is used, the face color of the other party can be faithfully reproduced during remote medical treatment over a network.

  In an image display device, there is a desire to display an input image after correcting it according to the display environment. In an environment in which an image is transmitted to a remote place and displayed, there is a demand for displaying the input image so that it looks the same as the creation place, for example, the appearance at the shooting place.

  In a system in which two image display devices are connected via a network and both display the same image, the user wants to display the image in the same color regardless of the difference in ambient light, and the appearance under the other's ambient light. Sometimes you want to display an image with the same look. For example, when a still image or a moving image is displayed on two image display devices for presentation or for viewing or reporting, it is necessary to faithfully reproduce the color of the image. In addition, there may be a case where it is desired to match the appearance in the environment of the transmission side or the reception side in order to obtain a sense of reality.

  An object of this invention is to show the image display apparatus which can satisfy | fill such a request.

An image display device according to the present invention includes an image input unit, an input image determination unit that determines an input image by the image input unit, an ambient light information acquisition unit that acquires ambient light information, and the input image that is the ambient light. An image correcting unit that corrects according to the ambient light information acquired by the information acquiring unit, the image correcting unit controlling whether or not correction is necessary according to a determination result of the input image determining unit, and an output image of the image correcting unit An image display device comprising a display means for displaying , comprising a communication means for receiving an image taken by a camera connected via a network and ambient light information thereof, wherein the image correction means is received by the communication means. and means for correcting in accordance with the ambient light information the photographed image, characterized in that it is controlled the necessity of correction in accordance with the determination result of the input image judging unit

  According to the present invention, since the presence / absence of the ambient light correction or the amount of the correction is controlled according to the input image, a more realistic image or a more faithful color reproduction image is displayed. be able to.

  The same operation / control can be performed on an image transmitted via a network such as a TV conference system. This makes it possible to display the other party's appearance as if the other party is here, or to display materials such as presentations that are displayed with the same faithful color reproducibility as the other party is viewing. Can see.

It is a schematic block diagram of one Example of this invention. FIG. 2 is a configuration block diagram showing the embodiment shown in FIG. 1 in more detail. It is an operation | movement flowchart of the Example shown in FIG. It is a schematic block diagram of the second embodiment of the present invention. It is an operation | movement flowchart of the Example shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic block diagram of an embodiment of an image display apparatus according to the present invention. The control unit 12 controls each block of the image display device 10. An image signal from an information processing apparatus 40 such as a personal computer (PC) is input to the image input unit 14. The image input unit 16 receives an image signal from a camera 44 that captures a subject (for example, a person) 42 on the spot. The input image determination unit 18 determines an image input from the image input units 14 and 16.

  The ambient light sensor 20 measures ambient light of the image display device 10 (in the illustrated example, illumination light of the illumination light source 46). The ambient light information acquisition unit 22 controls the ambient light sensor 20 and acquires the result of measuring the illumination light from the illumination light source 46 as ambient light measurement information. The image correction unit 24 corrects the input image from the input image determination unit 18 based on the ambient light information from the ambient light information acquisition unit 22.

  The image conversion unit 26 converts the resolution of the output image of the image correction unit 24 for display. The image conversion unit 26 may also be responsible for conversion from an interlace signal to a progressive signal (I / P conversion). The display unit 28 expands and displays the output image data of the image conversion unit 26 on the display element.

  FIG. 2 shows a more detailed block diagram of the image display device 10. The image display device 10 shown in FIG. 2 is a so-called liquid crystal projector. Constituent elements having the same functions as those in FIG.

  The user can input various instructions to the control unit 12 through the operation unit 50. The power source unit 52 includes a battery, an AC power source, or both, and supplies necessary power to each unit of the image display device.

  The display unit 28 includes a light source 54, a liquid crystal display panel 56 as a spatial light modulator that spatially modulates output light from the light source 54, and a projection optical system that projects display image light whose intensity is modulated by the liquid crystal display panel 56 onto a screen. 58. The light source controller 60 controls on / off of the light source 54 and the output light quantity. The liquid crystal driving unit 62 drives the liquid crystal display panel 56 according to the input image signal, and causes the liquid crystal display panel 56 to display an image. The liquid crystal display panel 56 includes one or three liquid crystal panels that can display an image. The optical system control unit 64 controls the zoom lens and focus lens of the projection optical system 58 in order to adjust the zoom magnification and focus of the projection optical system 58. The light source photometry unit 66 measures the light quantity or luminance of illumination light emitted from the light source 54.

  Here, the image input units 14 and 16 are composed of HDMI terminals or the like, and digital video signals are input from an external PC or DVD playback device or the like. In the case of an HDMI terminal, a control signal may also be transmitted from the outside at the same time, and thereby video control or the like may be performed. Of course, the image input units 14 and 16 may be configured by an analog video signal input terminal and an A / D converter that converts the analog video signal into a digital signal. In addition, a communication device that receives image data or the like via a USB interface or a network may be used.

  In addition to the functions described above, the image conversion unit 26 doubles the frame rate as the video signal of the output image of the image correction unit 24 for AC driving of the liquid crystal display panel 56. If necessary, conversion from an interlace signal to a progressive signal (I / P conversion) is also performed. The AC drive of the liquid crystal display panel is a method of displaying by alternately switching the direction of the voltage applied to the liquid crystal of the liquid crystal display panel. The liquid crystal display panel utilizes the property that an image can be generated regardless of whether the direction of the voltage applied to the liquid crystal is the forward direction or the reverse direction. At this time, since it is necessary to send the image for the forward direction and the image for the reverse direction one by one to the liquid crystal drive unit 62, the image conversion unit 26 doubles the number of frames of the video signal. The liquid crystal drive unit 62 drives the liquid crystal display panel 56 with alternating current based on the image signal from the image conversion unit 26 to display an image.

  When an image is projected on the screen from an oblique direction, the projection screen on the screen is distorted into a trapezoidal shape, for example. The image conversion unit 26 deforms the shape of the image so as to cancel such distortion in advance. This process is called keystone correction. When performing keystone correction, the enlargement / reduction ratio in the horizontal direction and / or vertical direction of the image displayed on the liquid crystal display panel 56 is changed. In this way, the distortion of the trapezoidal shape of the projection screen is offset by the distortion of the video area on the liquid crystal display panel, and the projected image is displayed on the screen in a shape approaching a rectangular video display with a normal aspect ratio. The keystone correction may be automatically performed based on the tilt angle obtained by the tilt sensor 68, or may be operated in accordance with the operation of the operation unit 50 by the user.

  The tilt sensor 68 detects the tilt of the image display device 10. The timer 70 detects the operation time of the image display device 10 and the operation time of each block. The thermometer 72 measures the temperature of the light source 54 of the image display device 10, the temperature of the liquid crystal display panel 56, the outside air temperature, and the like. The focus detection unit 74 detects the distance between the image display device 10 and a screen (not shown). The information display unit 76 displays the status of the image display device 10 and warnings. The cooling unit 78 cools the image display device 10 by releasing the heat in the image display device 10 to the outside. The cooling unit 78 includes, for example, a heat sink and a fan.

  The operation of the image display apparatus 10 shown in FIG. 2 will be described with reference to the operation flowchart shown in FIG. As shown in FIG. 1, for example, an information processing apparatus 40 such as a PC is connected to the image input unit 14, and a camera 44 is connected to the image input unit 16.

  The control unit 12 determines whether there is a power-on instruction from the operation unit 50 (S1). When the power-on instruction is detected (S1), the control unit 12 instructs the power supply unit 52 to supply power to each block, and puts each block in a standby state (S2). Next, the control unit 12 instructs the light source control unit 60 to emit light from the light source 54 (S3).

  As preparation for projection, the control unit 12 instructs the optical system control unit 64 to adjust the projection optical system 58 based on distance information to the screen obtained by the focus detection unit 74 and the like. The optical system control unit 64 operates the zoom lens and the focus lens of the projection optical system 58 to form an image of the projection light on the screen screen.

  The control unit 12 instructs the ambient light information acquisition unit 22 to drive the ambient light sensor 20 to measure the ambient light of the image display device 10 (S4). Thereby, the control part 12 acquires environmental light data.

  The input image determination unit 18 determines an image signal input via the image input units 14 and 16 (S5). When the input image determination unit 18 determines that the captured image from the camera 44 is not input (S6), the image correction unit 24 adds a predetermined value to the input image based on the ambient light information from the ambient light information acquisition unit 22. Correction processing is performed (S7). When the image is a photographed image from the camera 44 (S6), the image correction unit 24 outputs the input image data as it is without performing image correction based on the ambient light information.

  The image conversion unit 26 converts the resolution of the image data from the image correction unit 24 into a resolution suitable for the liquid crystal display panel 56, and performs gamma correction, luminance unevenness correction, and keystone correction (S8).

  The liquid crystal drive unit 62 drives the liquid crystal display panel 56 according to the image signal processed by the image conversion unit 26. Thereby, the liquid crystal display panel 56 displays an image (S9). The output light of the light source 54 is spatially intensity-modulated by the image displayed on the liquid crystal display panel 56 and projected onto a screen (not shown) by the projection optical system 58. During the display projection, the control unit 12 detects the temperature of the light source 54 and the like with the thermometer 72. For example, when the temperature of the light source 54 becomes 40 ° C. or higher, the control unit 12 operates the cooling unit 78 to cool the light source 54.

  It is determined whether or not the user gives an instruction to turn off the power using the operation unit 50 (S10). When there is an instruction to turn off the power (S10), the control unit 12 instructs each block to end processing (S11). When preparation for termination is completed, the power supply unit 52 sequentially ends power supply to each block. The cooling unit 78 operates for a while after the power is turned off. When the necessary part is cooled, the image display device 10 ends the series of operations.

  As described above, in this embodiment, the input image is determined, and whether or not the ambient light correction is necessary for the input image is controlled. That is, it controls whether to display an image with a sense of presence or to display an image with more faithful color reproduction depending on the content of the input image.

  In this embodiment, whether or not the ambient light correction is performed is controlled based on whether or not the image to be displayed is a captured image from the camera, but the present invention is not limited thereto. It is only necessary to determine whether the image should be displayed while being influenced by the ambient light, or whether the input image is an image that is displayed after canceling the influence of the ambient light. For example, it may be determined that the ambient light correction is performed based on whether the image is from an information processing apparatus such as a PC. For example, the same effect can be obtained even with an image created by application software for document creation, table formation, or report creation, or a CAD diagram, a moving image for viewing and examination, or a still image.

  The input image determination unit 18 may determine by directly analyzing the image itself or may be determined by a flag added to the image, a tag, metadata, a control command, or the like. Furthermore, the same effect can be obtained even if it is determined based on input signal information or identification information based on an external operation by a user or the like.

  As an example of directly determining the image itself, subject detection / person detection in the image may be performed, and determination may be performed according to the result. When a subject designated in advance by subject recognition is detected and recognized, a determination may be made according to this result.

  The same effect can be obtained by controlling the correction amount of the ambient light correction according to the input image, or by canceling the ambient light at the time of shooting the input image. By doing in this way, it becomes possible to display an image with higher precision and presence.

  In the present embodiment, as the ambient light sensor 20 for acquiring ambient light information, an image sensor or a photometric sensor other than the dedicated sensor may be used. The ambient light may be directly measured, or the reflected light from a screen or the like may be measured.

  In the configuration shown in FIG. 2, a liquid crystal display panel is used, but it can also be applied to a projector having a built-in DMD panel, a CRT image monitor, or a TV receiver. Even in a system including an image display device such as a TV conference system, or in a process / algorithm for changing the amount of ambient light correction by an input image, the same effect can be obtained.

  Next, an embodiment will be described in which the present invention is applied to a system in which two image display devices are connected via a network, such as a video conference system, and one display image is transmitted to the other and displayed.

  In the conference rooms A and B, image display devices 10A and 10B in which communication units 48A and 48B are added to functional elements corresponding to the image display device 10 shown in FIG. In the conference room A, the same functional blocks as those shown in FIG. Similarly, in conference room B, the same functional block as that shown in FIG. The image display devices 10A and 10B further include functional elements shown in FIG. When the image display device 10A displays an image transmitted from the image display device 10B, the image display device 10B becomes an image transmission device that transmits an image to the image display device 10A. Conversely, when the image display device 10B displays the image transmitted from the image display device 10A, the image display device 10A becomes an image transmission device that transmits an image to the image display device 10B.

  The control units 12A and 12B can transmit and receive various data and control signals to and from the image display apparatuses 10B and 10A via the network 80 using the communication units 48A and 48B. The network 80 is, for example, a LAN, a WAN, or the Internet. In order to facilitate understanding, it is assumed that the illumination light sources 46A and 46B are of different types.

  FIG. 5 shows an operation flowchart of the system shown in FIG. The operation of the system shown in FIG. 4 will be described with reference to FIG. In the image display device 10A, the image signal from the information processing device 40A is input to the image input unit 14A. An image signal from a camera 44A that captures a subject (for example, a person) 42A on the spot is input to the image input unit 16A. Similarly, in the image display device 10B, the image signal from the information processing device 40B is input to the image input unit 14B. An image signal from a camera 44B that captures a subject (for example, a person) 42B on the spot is input to the image input unit 16B.

  First, the operation in the TV conference room A will be described. The control unit 12A of the image display device 10A determines whether there is a power-on instruction from the operation unit (S21). In response to the power-on instruction, the control unit 12A instructs the power supply unit to supply power to each block, and puts each block in a standby state (S22).

  The controller 12A causes the projection light source to emit light in preparation for projection display (S23). The zoom and focus of the projection optical system are adjusted from the distance information to the screen and the like, and the projection light is imaged on the screen screen.

  In parallel with the projection preparation operation, the control unit 12A instructs the ambient light information acquisition unit 22A to drive the ambient light sensor 20A to measure the ambient light of the image display device 10A (S24). Thereby, control part 12A acquires environmental light data.

  The control unit 12A uses the communication unit 48A to specify the specified one of the input images of the image input units 14A and 16A, the additional information, and the ambient light data acquired in step S24 to the image display device 10B in the conference room B. Transmit (S25). In parallel with this transmission operation, the control unit 12A receives the information (image, its additional information, and ambient light data) transmitted from the image display device 10B in the conference room B via the communication unit 48A (S26).

  The control unit 12A selects which of the input images of the image input units 14A and 16A and the image input from the communication unit 48A (image from the image display device 10B) is to be displayed (S27). When displaying an image input from the communication unit 48A (image from the image display device 10B), the control unit 12A supplies the image data from the communication unit 48A to the input image determination unit 18A.

  The control unit 12A causes the input image determination unit 18A to determine the content of the image selected for display (S28). When the image selected for display is a captured image input from the image input units 14A and 16A of the image display device 10A (S28), the image correction unit 24A does not correct the image data from the input image determination unit 18A. Through. When the captured image is from the image display device 10B (S28), the image correction unit 24A refers to the ambient light data from the conference room B, that is, the captured environment information, and cancels the ambient light in the conference room B. The correction is applied to the input image data (S29).

  When the image selected for display is not a photographed image (S28), the image correction unit 24A refers to the ambient light information from the ambient light information acquisition unit 22A and performs correction so as to cancel the ambient light in the conference room A. Is applied to the input image data (S30). That is, image correction that cancels the influence of the illumination light source 46A is applied.

  The image conversion unit 26A converts the resolution of the image data from the image correction unit 24A into a resolution suitable for the liquid crystal display panel of the display unit 28A, and performs gamma correction, luminance unevenness countermeasure correction, and keystone correction (S31). The display unit 28A projects and displays the image from the image conversion unit 26A (S32).

  It is determined whether or not the user has instructed to turn off the power (S33). When there is an instruction to turn off the power (S33), the control unit 12A instructs each block to end processing (S34). When preparation for completion is completed, the power supply unit of the image display device 10A sequentially ends power supply to each block, and the image display device 10A ends a series of operations.

  The operation of the image display device 10B in the TV conference room B will be described. Basically, the operation is the same as that of the image display device 10A except that the image correction according to the content of the input image is changed.

  The control unit 12B of the image display device 10B determines whether there is a power-on instruction from the operation unit (S41). In response to the power-on instruction, the control unit 12B instructs the power supply unit to supply power to each block, and puts each block in a standby state (S42).

  The control unit 12B causes the projection light source to emit light in preparation for projection display (S43). The zoom and focus of the projection optical system are adjusted from the distance information to the screen and the like, and the projection light is imaged on the screen screen.

  In parallel with the projection preparation operation, the control unit 12B instructs the ambient light information acquisition unit 22B to drive the ambient light sensor 20B to measure the ambient light of the image display device 10B (S44). Thereby, control part 12B acquires environmental light data.

  The control unit 12B transmits the specified one of the input images of the image input units 14B and 16B and its additional information, and the ambient light data acquired in step S44, to the image display device 10A through the communication unit 48B (S45). ). In parallel with this transmission operation, the control unit 12B receives the information (image, its additional information, and ambient light data) transmitted from the image display device 10A via the communication unit 48B (S46).

  The control unit 12B selects which of the input images of the image input units 14B and 16B and the image input from the communication unit 48B (image from the image display device 10A) is to be displayed (S47). When displaying an image input from the communication unit 48B (image from the image display device 10A), the control unit 12B supplies the image data from the communication unit 48B to the input image determination unit 18B.

  The control unit 12B determines the correction amount of image correction for the image selected for display (S48). As a correction amount determination method, there is a method of selecting a plurality of 3D-LUTs or the like prepared in advance according to an input image. Further, a method of obtaining by calculating the input image parameter and the ambient light data, a method of determining based on the ambient light data transmitted from the conference room A via the network 80, or the like may be used. The image correction unit 24B corrects the image data from the input image determination unit 18B with the determined correction amount (S49).

  The image conversion unit 26B converts the resolution of the image data from the image correction unit 24B into a resolution suitable for the liquid crystal display panel of the display unit 28B, and performs gamma correction, luminance unevenness countermeasure correction, and keystone correction (S51). The display unit 28B projects and displays the image from the image conversion unit 26B (S52).

  It is determined whether or not the user has instructed to turn off the power (S53). When there is an instruction to turn off the power (S53), the control unit 12B instructs each block to end processing (S54). When preparation for termination is completed, the power supply unit of the image display device 10B sequentially ends power supply to each block, and the image display device 10B ends a series of operations.

  As described above, in this embodiment, whether or not the ambient light correction is performed on the input image is controlled according to the determination result of the input image in the image display apparatus constituting the TV conference system via the network. As a result, it is possible to display an image of the other party participant in the TV conference as a realistic image, or to display a presentation material or the like as a color reproduction more faithfully.

  Whether or not to apply correction based on ambient light is controlled depending on whether or not an image to be displayed is a captured image, but the present invention is not limited to this. That is, it is only necessary to determine whether the image should be displayed while being influenced by the ambient light, or the image should be displayed after canceling the influence of the ambient light. For example, it may be determined that the ambient light correction is performed based on whether the image is from an information processing apparatus such as a PC. For example, the same effect can be obtained even with an image created by application software for document creation, table formation, or report creation, or a CAD diagram, a moving image for viewing and examination, or a still image.

  The input image determination units 18A and 18B may determine by directly analyzing the image itself, or may be determined by a flag added to the image, a tag, metadata, a control command, or the like. Furthermore, the same effect can be obtained even if it is determined based on input signal information or identification information based on an external operation by a user or the like.

  As an example of directly determining the image itself, subject detection / person detection in the image may be performed, and determination may be performed according to the result. When a subject designated in advance by subject recognition is detected and recognized, a determination may be made according to this result.

  The same effect can be obtained by controlling the correction amount of the ambient light correction according to the input image, or by canceling the ambient light at the time of shooting the input image. By doing in this way, it becomes possible to display an image with higher precision and presence.

  In this embodiment, as the ambient light sensors 20A and 20B for acquiring ambient light information, an image sensor or a photometric sensor for other purposes may be used in addition to a dedicated sensor. The ambient light may be directly measured, or the reflected light from a screen or the like may be measured.

10, 10A, 10: Image display devices 18, 18A, 18B: Input image determination units 20, 20A, 20B: Ambient light sensors 22, 22A, 22B: Ambient light information acquisition units 24, 24A, 24B: Image correction units

Claims (4)

Image input means;
Input image determination means for determining an input image by the image input means;
Ambient light information acquisition means for acquiring ambient light information;
Image correction means for correcting the input image according to the ambient light information acquired by the ambient light information acquisition means, wherein the image correction means is controlled to determine whether or not correction is required according to the determination result of the input image determination means;
Display means for displaying an output image of the image correction means
An image display device comprising:
Comprising a communication means for receiving an image taken by a camera connected via a network and its ambient light information;
The image correction means is a means for correcting the captured image received by the communication means according to the ambient light information, and the necessity of correction is controlled according to the determination result of the input image determination means. An image display device characterized by that.   The image display apparatus according to claim 1, wherein the input image determination unit determines whether or not the input image is a captured image.   2. The input image determining means determines whether the input image is an image to be displayed while being influenced by ambient light or an image to be displayed after canceling the influence of ambient light. The image display device described in 1. The input image judging unit, a flag is added to the input image, tag, metadata, control commands, as well as by any of the input signal information 及 beauty identification information based on the operation from the outside, it determines the input image The image display device according to claim 3 .

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