JP5041874B2 - Intercom device with TV - Google Patents

Description

  The present invention comprises an intercom handset installed outdoors and an intercom base unit installed indoors. The intercom base station and the interphone base unit communicate with each other by transmitting audio signals to each other and intercom handsets. The present invention relates to an interphone apparatus with a television set in which an image captured by an imaging apparatus provided in a monitor is transmitted to an interphone master unit and displayed on a display device provided in the interphone master unit.

As a conventional interphone device with a television, a wide-angle lens is mounted on the image pickup device provided in the intercom handset, and a part of one screen imaged with a wide angle of view, for example, an area where a visitor's face is shown There has been provided a display which enlarges and displays the size of one screen using a processing technique (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 6-38214

  By the way, the image pickup apparatus provided in the intercom handset has an exposure control function for controlling the exposure of the captured image to an appropriate level, a color balance control function for controlling a color balance (also referred to as white balance) in a color image, A gradation characteristic control function for controlling the gradation characteristic of the video signal, an outline enhancement function for enhancing the outline of the subject, and the like are installed. Conditions (control conditions) for performing control by these functions, for example, Even if the position in the screen of the evaluation area that evaluates the signal strength of the video signal when performing exposure control is optimal for the video signal for one screen before expansion, it is optimal for the video signal after expansion. Not necessarily, but when you enlarge a part of the image that was controlled to the optimal exposure before enlargement, the exposure of the enlarged image becomes higher or the exposure becomes lower A.

  The present invention has been made in view of the above circumstances, and a purpose thereof is a television capable of appropriately performing exposure control, color balance control, gradation characteristic control, and contour cooperative control even for an enlarged image. It is to provide an attached intercom device.

In order to achieve the above object, the invention of claim 1 comprises an intercom handset installed outdoors and an interphone base unit installed indoors, and the interphone base unit and the interphone base unit are mutually connected. In an interphone device with a television set that transmits a voice signal and makes a phone call, and an image captured by an imaging device provided in the interphone slave unit is transmitted to the interphone master device and displayed on a display device provided in the interphone master device. An imaging device includes an imaging device that converts incident light into an electrical signal, an exposure control unit that controls exposure of a video signal output from the imaging device, and a color balance control that controls color balance of the video signal output from the imaging device. Means, a gradation characteristic control means for controlling the gradation characteristic of the video signal output from the image sensor, and the degree of contour enhancement of the video signal output from the image sensor. Setting a contour enhancement control means, the photographing mode and illuminating means for illuminating only the center portion of the image capturing element is output, the amount of light incident on the imaging device to illuminate by controlling the illuminating means is less than the predetermined value The interphone handset expands an arbitrary area smaller than the one screen to the size of the one screen by performing signal processing on the video signal for one screen output from the imaging device. and expansion processing means for generating a video signal for and displaying, in accordance with the position of the region to be enlarged by the enlargement processing unit, wherein the exposure control means, the color balance control unit, either at least one of the gradation control means or by changing the control conditions in one unit, and in accordance with the magnification of the area to be enlarged by the enlargement processing unit, wherein the exposure control means, the color balance control unit, of the contour cooperative control means And a control condition changing means for changing a control condition in at least one of the means, control conditions changed by the control condition changing means, the signal strength of the video signal for exposure control means exposure control in one screen The position of the evaluation area where the color balance control means evaluates the color balance of the video signal for color balance control within one screen, and the control condition changing means is the shooting mode setting means When the shooting mode is set to illuminate by the illumination means, the position of the evaluation area where the exposure control means evaluates the signal intensity of the video signal for exposure control within one screen is set to the center of the unenlarged screen or It changes to the vicinity .

According to the first aspect of the present invention, the exposure control means, the color balance control means, and the gradation according to the position of the area enlarged by the enlargement processing means and the enlargement magnification by the control condition changing means provided in the intercom handset. Since the control condition in at least one of the control means and the contour emphasis control means is changed, exposure control, color balance control, gradation characteristic control, and contour cooperative control are appropriately applied to an enlarged image. Can be done. In addition, exposure control, color balance control, gradation characteristic control, and contour cooperative control can be appropriately performed even when the shooting mode set by the shooting mode setting unit of the imaging apparatus is changed. Further, the exposure is not controlled based on the signal intensity of the video signal around the screen that is not illuminated by the illumination means, and the exposure of the enlarged video can be prevented from becoming higher than an appropriate level.

According to a second aspect of the present invention, in the first aspect of the invention, the control condition changing means sets the region enlarged by the enlargement processing means to a position above the center position in the vertical direction of the screen that is not enlarged. If it is, the position of the evaluation area where the exposure control means evaluates the signal intensity of the video signal for exposure control within one screen is changed below the center position.

According to the invention of claim 2 , when the area enlarged by the enlargement processing means is set at a position higher than the center position in the vertical direction of the non-enlarged screen, a high-luminance sky is present in the screen. In such a case, the position of the evaluation area in which the control condition changing unit evaluates the signal intensity of the video signal for exposure control is set to be higher than the central position. Therefore, the exposure of the enlarged image can be prevented from becoming lower than an appropriate level.

According to a third aspect of the present invention, in the first or second aspect of the invention, the control condition changing means increases the degree of contour emphasis by the contour emphasis control means as the enlargement magnification increases.

According to the invention of claim 3 , since the sharpness of the enlarged image generally decreases as the enlargement magnification increases, the degree of contour enhancement by the contour enhancement control means increases as the enlargement magnification increases. The sharpness of the enlarged image can be improved.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, the control condition changing means shifts the frequency range of contour emphasis by the contour cooperative control means to the low frequency side as the enlargement magnification increases. .

According to the invention of claim 4 , since the sharpness of the enlarged image generally decreases as the enlargement magnification increases, the frequency range of the contour emphasis by the contour emphasis control means decreases as the enlargement magnification increases. The sharpness of the enlarged image can be improved by shifting to the side.

The invention of claim 5 is the invention according to any one of claims 1 to 4 , wherein the enlargement processing means decreases the enlargement magnification as the area to be enlarged moves away from the center of one screen before enlargement. To do.

According to the invention of claim 5 , even if the position of the area to be enlarged changes, the size of the subject shown on the screen can be made substantially the same.

  According to the present invention, exposure control, color balance control, gradation characteristic control, and contour cooperative control can be appropriately performed even on an enlarged image.

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

  As shown in FIG. 1, the intercom apparatus with a television according to the present embodiment includes an image pickup apparatus 1 and is installed outdoors (for example, an exterior entrance of a dwelling unit). S and an interphone master unit (hereinafter abbreviated as “master unit”) M that is installed indoors (for example, in the living room of the dwelling unit) with the display device 100 built-in. Between the two, the voice signal is transmitted to each other via the signal line Ls to make a call, and an image captured by the imaging device 1 of the slave unit S is transmitted to the master unit M via the signal line Ls. It is displayed on the display device 100. However, since the configuration related to the telephone call is well known in the art, illustration and description thereof will be omitted.

  The master M is connected to a display device 100 such as an LCD panel and a display device 100 including a driver circuit that displays the video by driving the display device, and the slave unit S via the signal line Ls. A signal transmission unit 101 that performs frequency division multiplex transmission of signals and control signals, an operation input reception unit 102 that receives an operation input by a person, and the like are provided.

  The subunit | mobile_unit S is the signal transmission part 2 which frequency-division-multiplex-transmits an audio | voice signal, a video signal, and a control signal via the signal wire | line Ls between the imaging device 1 and the main | base station M, and the imaging device 1 outputs 1 A video signal for enlarging an arbitrary area smaller than the one screen (hereinafter referred to as “enlarged area”) to a size corresponding to the one screen is generated by performing signal processing on the video signal for the screen. And a control unit 4 that receives the control signal transmitted from the master unit M from the signal transmission unit 2 and executes necessary processing, and controls the imaging device 1 and the enlargement processing unit 3 as will be described later. And.

  The image pickup apparatus 1 includes an image pickup element 10 composed of a CCD image sensor or a CMOS image sensor, a lens 11 for condensing light on an image pickup surface of the image pickup element 10, and a light source such as a light emitting diode, and applies light to a subject. An illumination unit 12 that irradiates, a video signal processing unit 13 that performs signal processing on a video signal output from the image sensor 10, and a shooting mode setting unit 14 that sets a shooting mode of the imaging device 1 as will be described later. . Here, the image sensor 10 in the present embodiment can output a video signal compliant with the YUV422 video format, that is, a digital video signal composed of a Y luminance component and U and V color difference components. However, the video format of the digital video signal is an example and is not limited to the embodiment.

  The video signal processing unit 13 includes a frame memory that stores a video signal output from the image sensor 10. An exposure control process that controls exposure of the video signal with respect to the video signal stored in the frame memory, and a video signal Various signal processes including color balance control processing for controlling color balance, gradation characteristic control processing for controlling gradation characteristics of video signals, and edge enhancement control processing for controlling the degree of edge enhancement of video signals are performed. That is, in this embodiment, the video signal processing unit 13 corresponds to an exposure control unit, a color balance control unit, a gradation characteristic control unit, and an edge enhancement control unit.

  The exposure control process compares the level of the luminance component in an area smaller than the size of one screen (hereinafter referred to as “exposure evaluation area”) with a predetermined threshold (hereinafter referred to as “appropriate exposure value”). If the exposure value is lower than the appropriate exposure value, control is performed to increase the level of the luminance component by increasing the charge storage time in the image sensor 10. Conversely, if the exposure value is higher than the appropriate exposure value, the charge storage time in the image sensor 10 is shortened. In this way, the control is performed so as to lower the level of the luminance component. In the present embodiment, the charge accumulation time of the image sensor 10 is adjusted in the exposure control process. However, when an iris (aperture) is provided between the lens 11 and the image sensor 10, the iris opening degree is set. Exposure can also be controlled by adjusting.

  The color balance control process is a process of adjusting a conversion formula used for color space conversion from R, G, B to Y, U, V in the image sensor 10, and is an area smaller than the size of one screen (hereinafter, referred to as “color balance control process”). The value for the color difference components U and V of the color space conversion formula is adjusted so that the pixel having the highest luminance component level in the color balance evaluation area is close to white. The gradation characteristic control process is also a process for adjusting a conversion formula used for color space conversion from R, G, B to Y, U, V in the image sensor 10, and the luminance characteristic Y in the exposure evaluation area is adjusted. The value for the luminance component Y of the color space conversion equation is adjusted according to the maximum value. Furthermore, the contour cooperative control process separates the luminance component Y into a low-frequency component and a high-frequency component by a low-pass filter composed of a digital filter and amplifies only the high-frequency component and then adds the low-frequency component to the subject relative to the background. This is a process for emphasizing the outline of the image.

  The shooting mode setting unit 14 controls the illumination unit 12 to illuminate the subject when the amount of light incident on the image sensor 10 (for example, an average value or maximum value per unit time) is less than a predetermined value. The setting of the shooting mode (with or without illumination) is changed according to the brightness of the subject (luminance component Y of the video signal). The incident light amount can be obtained based on the charge accumulation time controlled by the exposure control process or the charge accumulation time and the luminance component level.

  The enlargement processing unit 3 performs processing for enlarging the enlargement area instructed by the control unit 4 at the same enlargement magnification instructed by the control unit 4, but specific enlargement processing is conventionally known. Description is omitted.

  In master device M, a frame indicating an enlargement area is appropriately displayed on the screen of display device 100. When operation input for selecting the position and enlargement magnification of the enlargement area by the user is accepted by operation input accepting unit 102, the enlargement is performed. Information indicating the position of the region and the magnification (magnification information) is transmitted from the signal transmission unit 101 by a control signal. In the slave unit S, the control signal transmitted from the master unit M via the signal line Ls is received by the signal transmission unit 2, and the control unit 4 obtains the enlarged information from the control signal to obtain the position of the enlarged region. The enlargement magnification is instructed to the enlargement processing unit 3.

  Further, the control unit 4 controls the control conditions in the exposure control process (position of the exposure evaluation area), the control conditions in the color balance control process (position of the color balance evaluation area), and gradation characteristics according to the position of the enlargement area and the enlargement magnification. Processing for changing the control conditions (position of the exposure evaluation area) in the control processing and the control conditions (frequency range: cutoff frequency of the low-pass filter, degree of contour enhancement: amplification degree of the high frequency component) in the contour enhancement control processing is also performed. That is, in the present embodiment, the control unit 4 corresponds to control condition changing means.

  Next, the control condition changing process in the control unit 4 will be described in more detail.

  First, a case where the control conditions for the exposure control process and the control conditions for the color balance control process are changed according to the position of the enlarged region will be described. 2 (a) and 2 (b) show images before magnification (hereinafter referred to as “original images”) captured by the imaging device 1 of the slave unit S, respectively, (a) is an original image in the daytime, and (b) ) Is the original video at night. In this original image, two buildings X1 and X2 are shown side by side in the center of the screen, with the sky in the upper half and the ground in the lower half. Further, what are indicated by broken lines in FIG. 2 are three enlarged regions W1, W2, and W3 having different positions. The enlarged area W1 is located in the upper right corner of the original image, and in the example shown in the drawing, the sky is shown almost entirely in the area. The enlarged area W2 is located at the center of the original image, and in the illustrated example, a part of the two buildings X1 and X2 are shown in almost the entire area. Furthermore, the enlarged area W3 is located at the lower left corner of the original image, and in the example shown in the drawing, the ground is shown in almost the entire area.

  For example, in the daytime original image shown in FIG. 2A, when the enlarged area W1 in the upper right corner is enlarged, most of the enlarged area W1 is occupied by the sky, so that the entire area becomes the exposure evaluation area. There is a risk that the exposure will be too low and subjects other than the sky will be blacked out and displayed, and if the entire area is made the color balance evaluation area, the sky with the large luminance component Y will become white and the color balance will shift. There is a risk that. In addition, in the daytime original image shown in FIG. 2A, when the enlarged area W3 in the lower left corner is enlarged, most of the enlarged area W3 is occupied by the ground, so a part of the area is set as an exposure evaluation area. If this happens, the exposure will be too high and the object outside the ground may fly white and be displayed. If a part of the area is set as the color balance evaluation area, the wall surface of the building X1 having a large luminance component Y will be white. As described above, the color balance may be shifted.

  Further, at night, the shooting mode setting unit 14 sets the shooting mode in which the illumination unit 12 performs illumination. When the irradiation range Z of the illumination unit 12 is only the central portion in the original image, the irradiation is performed as shown in FIG. Since the level difference of the luminance component Y is very large inside and outside the range Z, the range in which the level of the luminance component Y increases depending on the position of the enlarged region, and the entire enlarged region is used as an exposure evaluation area or a color balance evaluation area. Therefore, it becomes difficult to control the exposure and color balance appropriately.

  Therefore, in the present embodiment, as shown in FIG. 4, the position of the enlarged region W is classified into three types of up, middle, and bottom in the vertical direction, and the level of the luminance component Y of the video signal is 3 The control unit is classified into stages, and the evaluation area (exposure evaluation area and color balance evaluation area) R is narrowed and shifted downward as the position of the enlarged area W increases for the same luminance component Y level. 4 gives an instruction to the video signal processing unit 13. When the enlargement region W is “up”, the control unit 4 gives an instruction to the video signal processing unit 13 so as to shift the evaluation area R narrower and lower regardless of the level of the luminance component Y, and enlarges. When the region W is “down”, the control unit 4 instructs the video signal processing unit 13 to shift the luminance component Y so that it is narrower and upward as the level of the luminance component Y becomes lower, and the enlarged region W is “medium”. In some cases, the control unit 4 gives an instruction to the video signal processing unit 13 so as to shift the luminance component Y narrower and lower as the level of the luminance component Y becomes higher.

  If the control unit 4 changes the control conditions of the exposure control process and the color balance control process in the video signal processing unit 13 according to the rules as described above, an appropriate exposure is always performed according to the position of the enlarged region and the luminance component Y of the video signal. The quality of the image displayed on the display device 100 of the parent device M can be improved by performing the control and the color balance control. In the above description, the case where the enlargement magnification is made constant is described. However, even when the enlargement magnification is changed, the control unit 4 similarly performs exposure control processing and color in the video signal processing unit 13 according to predetermined rules. What is necessary is just to change the control conditions of balance control processing.

  Then, the case where the control conditions of a contour cooperative control process are changed according to an expansion magnification is demonstrated.

  The spatial frequency characteristic (MTF: Modulation Transfer Function) of the video signal output from the imaging device 1 is deteriorated from the original video by enlarging the video as shown in FIG. Therefore, in the present embodiment, as the enlargement magnification becomes higher, control is performed so that the frequency range (cut-off frequency of the low-pass filter) is shifted to the lower frequency side and the degree of contour enhancement is increased (the amplification degree of the high-frequency component is increased). The unit 4 gives an instruction to the video signal processing unit 13 to compensate for the deterioration of the spatial frequency characteristic, thereby improving the quality of the video displayed on the display device 100 of the parent device M.

  By the way, when there is no distortion aberration of the lens 11 included in the imaging apparatus 1 or the distortion is small enough to be ignored in practical use, as shown in FIG. When there are a plurality of subjects (three persons H1, H2, and H3 in the illustrated example) above, as shown in FIG. 6B, the persons H1 and H3 that are on the left and right sides compared to the person H2 that is at the center of the screen. Will appear larger. Therefore, if the control unit 4 instructs the enlargement processing unit 3 to reduce the enlargement magnification as the enlargement area shifts from the center to the periphery, any person H1, H2, H3 is enlarged and displayed in the above case. Even in this case, it is possible to display on the display device 100 with substantially the same size.

It is a block diagram which shows embodiment of this invention. It is operation | movement explanatory drawing same as the above. It is operation | movement explanatory drawing same as the above. It is explanatory drawing for demonstrating the change rule of the evaluation area in the same as the above. It is explanatory drawing of the spatial frequency characteristic of an imaging device same as the above. It is operation | movement explanatory drawing same as the above.

Explanation of symbols

M Interphone main unit S Interphone handset 1 Imaging device 3 Enlargement processing unit (enlargement processing means)
4 Control unit (control condition changing means)
10 Image sensor 13 Video signal processing section (exposure control means, color balance control means, gradation characteristic control means, contour cooperative control means)

Claims (5)

It consists of an intercom handset installed outdoors and an intercom base unit installed indoors. The intercom handset and the interphone base unit communicate with each other by transmitting audio signals to each other and installed in the intercom handset. In the interphone device with a TV, the video captured by the image capturing device is transmitted to the interphone master unit and displayed on the display device provided in the interphone master unit.
An imaging device includes an imaging device that converts incident light into an electrical signal, an exposure control unit that controls exposure of a video signal output from the imaging device, and a color balance control that controls color balance of the video signal output from the imaging device. Means, gradation characteristic control means for controlling gradation characteristics of the video signal output from the image sensor, contour enhancement control means for controlling the degree of contour enhancement of the video signal output from the image sensor, and video output from the image sensor Illuminating means for illuminating only the central part of the imaging device, and a photographing mode setting means for setting the photographing mode for controlling and illuminating the illuminating means when the amount of light incident on the image sensor is less than a predetermined value ,
The intercom handset processes a video signal for one screen output from the imaging device, thereby expanding a video signal for displaying an arbitrary area smaller than the one screen to the size of the one screen. changes and enlargement processing means for creating, in accordance with the position of the region to be enlarged by the enlargement processing unit, wherein the exposure control means, the color balance control unit, the control conditions in at least one of means of gradation control means And a control condition for changing a control condition in at least one of the exposure control means, the color balance control means, and the contour cooperative control means in accordance with the enlargement magnification of the area enlarged by the enlargement processing means and a changing means, control conditions changed by the control condition changing means, evaluation areas exposure control unit evaluates the signal strength of the video signal for control exposure in one screen The position, or the position of the evaluation area where the color balance control means evaluates the color balance of the video signal for color balance control within one screen, and the control condition changing means is illuminated by the photographing mode setting means. When the shooting mode is set, the position of the evaluation area where the exposure control means evaluates the signal intensity of the video signal for exposure control within one screen is changed to the center of the screen that is not enlarged or the vicinity thereof. An interphone device with a TV. The control condition changing means is configured such that when the area enlarged by the enlargement processing means is set at a position above the center position in the vertical direction of the screen that is not enlarged, the exposure control means performs exposure control within one screen. Therefore, the intercom apparatus with a television set according to claim 1 , wherein the position of the evaluation area for evaluating the signal intensity of the video signal is changed below the center position . The intercom apparatus with a television according to claim 1 or 2 , wherein the control condition changing means increases the degree of contour enhancement by the contour enhancement control means as the enlargement magnification increases . The intercom apparatus with a television according to claim 1 or 2 , wherein the control condition changing means shifts the frequency range of contour emphasis by the contour cooperative control means to the low frequency side as the enlargement magnification increases . The interphone apparatus with a television according to any one of claims 1 to 4, wherein the enlargement processing unit decreases the enlargement magnification as the area to be enlarged moves away from the center of one screen before enlargement .

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