JP4784411B2 - Video display system - Google Patents

Description

  The present invention relates to a video display system capable of sharpening a displayed image.

  Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2004-180165 (Patent Document 1), a video display system capable of sharpening processing is known. As shown in FIG. 3, the video display system includes an imaging device 91 capable of adjusting exposure, A / D conversion means 92 for A / D converting the output of each pixel of the imaging device 91, and A / D conversion. A histogram creating means 93 for creating a histogram based on the output of the means 92, a histogram edge removing means 94 for removing a part of the histogram, a centroid calculating means 95 for calculating the centroid of the histogram, and a preset reference range Comparing means 96 for calculating the direction and magnitude of the histogram centroid shift, and exposure control for controlling the exposure so that the histogram centroid approaches the reference value based on the histogram centroid shift direction and magnitude relative to the reference range. Means 97.

Therefore, in this case, by controlling the exposure of the imaging device 91, the entire image of the display unit (not shown) can be sharpened.
JP 2004-180165 A

  On the other hand, when the video display system is used in a TV door phone device for crime prevention, there is a problem that it is difficult to see a human image or the like reflected on the display unit depending on environmental conditions such as background light.

  However, in the conventional video display system described above, the video of the entire display unit is sharpened, and effective sharpening processing can be performed when it is desired to sharpen a specific area in the display unit. It was not a system. For example, in a TV door phone device, even if a clearing process is performed on the entire display unit, a region where a person image is displayed is not sharpened compared to other regions, and still depends on the intensity of background light. The figure of the person remained unclear.

  The present invention has been invented in view of the above-described background art, and an object thereof is to provide a video display system capable of sharpening a specific area in a display unit.

In order to solve the above problem, in the invention according to claim 1 of the present application, an imaging device, a display unit that displays an image captured by the imaging device, and a display unit that performs video signal processing on the image captured by the imaging device. The video display system includes a video signal processing unit that outputs and displays the image, and the display unit includes a touch panel, and controls the image sharpening process for the screen area touch-inputted in the display unit. An image analysis unit is provided, and the image analysis unit averages the brightness of a screen area to be sharpened selected by touch input, in which only the screen area is displayed with an average brightness limited to the screen area. Thus, the image sharpening process is performed.

Further, in the invention described in claim 2 of the present application, in the video display system according to claim 1, the image analysis unit is also performing the playback display even when the video recorded by the imaging device is played back on the display unit. The image sharpening process is performed by averaging the luminance with respect to the screen area to be sharpened, which is input by touching, on the video image.

According to a third aspect of the present invention, in the video display system according to the first or second aspect, the image analysis unit corrects the exposure of the imaging apparatus for the screen area to be sharpened selected by touch input. The image sharpening process is performed by performing the above.

Further, in the invention according to claim 4 of the present application, in the video display system according to claim 3, the image analysis unit creates a brightness histogram for the screen area to be sharpened that has been touch-input, and the brightness is set in advance. A range of a certain width from the maximum value and the minimum value is removed from the luminance histogram, the center of gravity of the remaining luminance histogram is calculated, and exposure correction of the imaging device is performed so that the center of gravity falls within a preset reference range. It is characterized by that.

In the video display system according to claim 1 of the present application, an image analysis unit that performs an image sharpening process on a screen area touch-inputted in the display unit is provided, and the image analysis unit performs the sharpening selected by touch input. The image sharpening process is performed on the target screen area by performing luminance averaging for displaying an image with an average luminance limited to the screen area only in the screen area . As a result, a specific area on the display unit can be selected and sharpened, and even if there is an area with a partially protruding luminance, it is affected by the protruding luminance by averaging in the selected area. A clear image can be displayed without any problem.

Further, in the video display system according to claim 2 of the present application , even when the video recorded by the imaging device is reproduced and displayed on the display unit, the screen to be clarified by touch input for the video being reproduced and displayed. Since it is possible to average the brightness of the area, even if there is an area with a partly protruding brightness, averaging the selected area makes it possible to clearly display the image without being affected by the protruding brightness. Can be displayed.

  Further, in the video display system according to claim 3 of the present application, by performing exposure correction of the imaging device, it is possible to cause the imaging device to take an image under appropriate conditions.

  In the video display system according to claim 4 of the present application, the image analysis unit performs calculation processing such as creation of a luminance histogram on the selected region to perform exposure correction, and therefore performs calculation on all the captured regions. Compared with processing, the processing load on the screen analysis unit can be further reduced, and the sharpening processing can be speeded up.

  Accordingly, since the followability to the change in brightness is improved, the system is particularly effective when the imaging apparatus is installed in an environment where the brightness is likely to change due to ambient light.

  1 and 2 show a video display system according to an embodiment of the present invention. This video display system includes an imaging device 11, a display unit 21 that displays an image captured by the imaging device 11, and a video that processes an image captured by the imaging device 11 for output display on the display unit 21. The video display system includes a signal processing unit 22, and the display unit 21 includes a touch panel, and includes an image analysis unit 23 that performs an image sharpening process on a screen area touch-inputted on the display unit 21. It is characterized by having prepared.

  As for the image sharpening process, it is possible to control the image sharpening process by performing a luminance averaging process or by performing exposure correction of the imaging device 11. In the exposure correction method, the image analysis unit 23 creates a luminance histogram for the touch-input screen area, removes a range of a predetermined width from the preset maximum and minimum luminance values from the luminance histogram, and remains. The center of gravity of the brightness histogram is calculated, and control is performed so that the center of gravity is within a preset reference range.

  Hereinafter, the video display system of this embodiment will be described in more detail. As shown in FIG. 2, this video display system is composed of a doorphone slave unit 1 installed outside the house and a master unit 2 installed in the house and connected to the doorphone slave unit 1 via a transmission line in the building. An audio signal and a video signal are transmitted between the master unit 2 and the doorphone slave unit 1 by a frequency modulation method. The intercom 1 is provided with an imaging device 11 that includes an imaging device having a plurality of pixels.

  As shown in FIG. 1, the base unit 2 includes a communication unit 24, a video signal processing unit 22, an audio signal processing unit 25, an audio input / output unit 28, a display unit 21, a control unit 26, and a power supply unit 27. And.

  The communication unit 24 is a communication interface between the imaging device 11 and separates a frequency multiplexed signal of audio and video sent from the transmission line by frequency multiplexing transmission, and sends the video signal to the video signal processing unit 22. The received voice signal is transmitted to the voice signal processing unit 25. Further, the communication unit 24 transmits the transmission voice signal sent from the voice signal processing unit 25 to the door phone slave unit 1 through the transmission line. The communication unit 24 A / D converts the output of each pixel transmitted from the imaging device 11 to generate luminance data, and transmits the luminance data to the control unit 26 as a part of the video signal. Here, the luminance data may be signal-processed by the video signal processing unit 22 and transmitted to the control unit 26 together with the RGB data, as is conventional.

  The video signal processing unit 22 performs video signal processing on the image captured by the imaging device 11 and transmits the processed video signal to the display unit 21 and the control unit 26 as a video signal. The voice signal processing unit 25 performs voice signal processing on the transmission voice and the reception voice, and communicates with the voice input / output unit 28 including a microphone and a speaker. To do.

  The display unit 21 includes a touch input unit 21a including a liquid crystal touch panel, and displays an image captured by the imaging device 11 on the touch input unit 21a. When the touch input unit 21a receives the touch input, the touch input unit 21a transmits a touch input signal for performing a display image sharpening process or the like to the control unit 26. Note that the touch input can select a plurality of areas at a time from among a plurality of divided areas that receive the touch input in the liquid crystal touch panel.

  When the control unit 26 receives a control signal that is frequency-multiplexed in a frequency band different from that of audio and video and is sent from the door phone slave unit 1, the video signal processing unit 22 according to the control request content of the control signal. Alternatively, various operations of the audio signal processing unit 25 are controlled. In addition, the control unit 26 is provided with an image analysis unit 23. When the image analysis unit 23 receives a touch input signal from the display unit 21, the image analysis unit 23 is based on the captured image captured from the video signal processing unit 22. It has a function of detecting a touch-input screen area and locally performing image sharpening processing only on this screen area. Further, the power supply unit 27 supplies the operating power for the entire master unit 2.

  It should be noted that in these video and audio transmission processes, since A / D conversion or D / A conversion is a conventional publicly known technique, description thereof is omitted.

  For example, as shown in FIG. 2, when this video display system is installed in an apartment house or the like, an ambient light source such as the lighting fixture 3 at the entrance of the dwelling unit located on the opposite side of the imaging device 11 may be stored on the screen. . In this case, since the human image 4 captured by the imaging device 11 becomes difficult to see with the ambient light source, it is effective to perform the sharpening process.

  Hereinafter, the sharpening process in the video display system will be described with reference to FIGS. The user in the home can select two types of sharpening processing methods, brightness averaging processing and exposure correction, as the display image sharpening processing. First, the luminance averaging process will be described.

  When a user in the home touches the specific area 5 such as a person image on the liquid crystal touch panel of the display unit 21, a touch input signal is transmitted to the control unit 26. Upon receipt of the touch input signal, the control unit 26 detects the touched specific area 5 in the image analysis section 23, reads luminance data limited to the specific area 5, and calculates an average brightness. The calculated average luminance data is transmitted as a sharpening processing signal from the control unit 26 to the video signal processing unit 22, and an image displayed on the display unit 21 is an image with the calculated average luminance only in the specific area 5. Controlled to display.

  Note that this luminance averaging process can also be used when playing back video recording data captured by the imaging device 11. Therefore, for example, in the case where the image of the suspicious person is recorded while the imaging device 11 is away, the face of the suspicious person can be clarified and used for crime prevention.

  Next, exposure correction will be described. Similar to the luminance averaging process, when the touch input signal is transmitted to the control unit 26, the image analysis unit 23 detects the specific area 5 and limits the pixel value data of the specific area 5 to the number of pixels with respect to the luminance. Create a luminance histogram to show. After the luminance histogram is created, in the same manner as the method shown in the conventional example (Japanese Patent Laid-Open No. 2004-180165), a range of a certain width from the preset maximum and minimum luminance values is removed from the luminance histogram, The center of gravity of the remaining luminance histogram and the difference between the reference range and the center of gravity are calculated.

  The calculation formula used for the calculation is the same as that in the conventional example (Japanese Patent Laid-Open No. 2004-180165), and is omitted here. The maximum value, minimum value, and reference range set in advance can be changed by the user as necessary.

  The control unit 26 transmits information such as the brightness histogram created by the image analysis unit 23, the calculated centroid and the difference between the reference range and the centroid to the communication unit 24 as a sharpening processing signal, and the calculated centroid is the reference. Exposure correction of the imaging device 11 is performed so as to fall within the range. Note that the exposure correction is performed by the imaging device 11 adjusting the aperture amount and shutter speed of the own device.

  Therefore, in the video display system according to this embodiment, the image analysis unit 23 that performs the sharpening process on the screen area touch-inputted on the display unit 21 is provided, so the specific region 5 on the display unit 21 is selected. It can be sharpened.

  In addition, since it is possible to perform luminance averaging processing on the selected area, even if there is an area with a partly protruding luminance, averaging is performed on the selected area without being affected by the protruding luminance. A clear image can be displayed. In addition, since the image sharpening process can be performed by performing exposure correction of the imaging device 11, the imaging device 11 can capture an image under appropriate conditions.

  Further, since this video display system can perform the above-described two types of sharpening processing, one of the sharpening processing can be selected as necessary.

  In addition, when this video display system is used for door phone equipment, in-home users can make the visitor stand out and make it easier to see even if the imaged visitor is difficult to see due to ambient light sources, etc. Therefore, the door phone device is more suitable for crime prevention.

  In addition, since the image analysis unit 23 performs an exposure correction by performing a calculation process such as creation of a luminance histogram for the selected region, the image analysis unit 23 is compared with the case of performing the calculation process for all the captured regions. The processing load can be further reduced, and the sharpening process can be speeded up.

  Accordingly, since the followability to the change in brightness is improved, the system becomes an effective system particularly in the case where the imaging device 11 is installed in an environment in which the brightness is likely to change due to ambient light.

  Alternatively, it is possible to use a low-speed arithmetic device that is less expensive than a conventionally used arithmetic device while maintaining the same followability as the conventional one, and the memory can be reduced, so that the cost can be reduced. .

It is a block diagram of the main | base station in the video display system of this invention. It is explanatory drawing which shows the video display system of this invention. It is a block diagram which shows the conventional communication system.

Explanation of symbols

11 Imaging device
21 display
22 Video signal processor
23 Image Analysis Department

Claims (4)

An image display system including an imaging device, a display unit that displays an image captured by the imaging device, and a video signal processing unit that processes the image signal captured by the imaging device and outputs the signal to the display unit The display unit includes a touch panel, and includes an image analysis unit that controls image sharpening processing for a screen area touch-inputted on the display unit, and the image analysis unit is selected by touch input. The image sharpening process is performed by averaging the brightness of the screen area to be sharpened only by displaying the image with the average brightness limited to the screen area. Video display system. When the video recorded by the imaging apparatus is reproduced and displayed on the display unit, the image analysis unit performs a luminance average on the screen area to be clarified touch-input for the video being reproduced and displayed. 2. The video display system according to claim 1, wherein the image sharpening process is performed by making the image clear.   3. The video according to claim 1, wherein the image analysis unit performs an image sharpening process on the screen area to be sharpened selected by touch input by performing exposure correction of the imaging apparatus. Display system.   The image analysis unit creates a brightness histogram for the touch-input screen area to be sharpened, removes a predetermined range from the preset maximum and minimum brightness from the brightness histogram, and the remaining brightness 4. The video display system according to claim 3, wherein the center of gravity of the histogram is calculated, and exposure correction of the imaging apparatus is performed so that the center of gravity is within a preset reference range.

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