JP2016213781A - Imaging apparatus, control method thereof, and control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut out a partial image with reduced deterioration in image quality without regard to the position of a cut-out area, when the partial image is cut out from a captured image.SOLUTION: In an imaging apparatus, an optical image is formed through an imaging lens 100 and a diaphragm 101, and an imaging sensor 103 outputs an image corresponding to the optical image. An image cut-out part 110 cuts out a designated cut-out area of the image as a partial image. An image cut-out position calculation part 107, a determination part 108, and an exposure control part 105 adjust the diaphragm and control exposure, in accordance with the position of the cut-out area in the image.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus, a control method thereof, and a control program, and more particularly, to an imaging apparatus that cuts out a designated area as a partial image from an image obtained as a result of imaging.

  2. Description of the Related Art In recent years, there is an omnidirectional camera (a monitoring camera provided with a lens having a horizontal and vertical angle of view of 180 ° or more) that can monitor and photograph a wide range in a monitoring camera that is one of imaging apparatuses. In surveillance cameras, the number of pixels of an image sensor is increasing, and there is a demand for miniaturization of the lens and the camera itself.

  Due to such demands, when the lens is miniaturized, the high-pixel image sensor is large, so resolution degradation and lens aberration are conspicuous due to a decrease in pixel density at the periphery of the image obtained as a result of shooting. End up.

  Further, when an image captured by a monitoring camera is displayed on a client device for monitoring, a user selects an area to be watched in the image and displays the selected area as a partial image. However, when a partial image is cut out by a surveillance camera with a miniaturized lens, it is assumed that an area including a peripheral portion of the image (entire image) is selected. In this case, as described above, degradation of resolution and lens aberration become conspicuous in the partial image. As a result, it is not possible to provide a partial image with image quality that satisfies the user.

  On the other hand, there is a surveillance camera in which a plurality of partial images are cut out from a captured image (captured image), and the image size is converted and output (see Patent Document 1). In this surveillance camera, focus control is performed with the focus position at which the function representing the maximum value of the circle of confusion with respect to the focus position is the minimum value as the focus focus position of the entire image, and each partial image is focused. ing.

  In addition, when a cutout area is selected in the surveillance camera, if the amount of optical aberration or the amount of decrease in peripheral light exceeds a predetermined threshold, the cutout area is displayed as a warning area on the display unit. (Patent Document 2).

JP 2007-322921 A JP 2011-55361 A

  However, in the above-mentioned Patent Document 1, since the focus positions regarding all the cut-out images (partial images) are averaged, it is not possible to obtain an optimum image quality for the partial image that the user wants to watch.

  Further, in the above-described Patent Document 2, when a user wants to cut out an area such as a peripheral part of an image, the user cannot cut out the area as a partial image only by giving a warning.

  Accordingly, an object of the present invention is to provide an imaging apparatus capable of performing clipping while suppressing degradation in image quality regardless of the position of the area to be cut out when cutting out a partial image from an image obtained as a result of imaging, a control method thereof, And providing a control program.

  In order to achieve the above object, an imaging apparatus according to the present invention is an imaging apparatus including an imaging element that forms an optical image through an imaging lens and a diaphragm and outputs an image corresponding to the optical image. The image processing apparatus includes: a clipping unit that clips a clipped region specified in an image as a partial image; and a control unit that performs exposure control by adjusting the diaphragm according to the position of the clipped region in the image.

  A control method according to the present invention is a control method for an imaging apparatus including an imaging element that forms an optical image through an imaging lens and a diaphragm and outputs an image corresponding to the optical image, and is designated in the image. A cutout step of cutting out the cutout region as a partial image, and a control step of performing exposure control by adjusting the diaphragm according to the position of the cutout region in the image.

  A control program according to the present invention is a control program used in an imaging apparatus including an imaging element that forms an optical image through an imaging lens and a diaphragm and outputs an image corresponding to the optical image. A computer comprising: a cutout step of cutting out a cutout area specified in the image as a partial image; and a control step of performing exposure control by adjusting the diaphragm according to the position of the cutout area in the image. It is characterized by.

  According to the present invention, the exposure is controlled by adjusting the aperture according to the position of the cutout area in the image, so that deterioration of image quality is suppressed regardless of the position of the cutout area when the partial image is cut out from the image. And can be cut out.

1 is a block diagram illustrating a configuration of an example of an imaging apparatus according to a first embodiment of the present invention. It is a flowchart for demonstrating the image clipping process performed with the surveillance camera shown in FIG. It is a figure for demonstrating calculation of the cut-out distance performed by the image cut-out position calculation part shown in FIG. It is a figure which shows the example about the relationship between an aperture stop and contrast evaluation value in the surveillance camera shown in FIG. FIG. 2 is a diagram illustrating an example of an aperture value corresponding to a distance from the center of an effective area of the image sensor in the monitoring camera illustrated in FIG. It is a figure which shows an example of the aperture value on the basis of image height in the surveillance camera shown in FIG. It is a figure which shows an example of the aperture value which considered the individual variation of the image pick-up element in the surveillance camera shown in FIG. It is a figure for demonstrating an example of the program diagram used by small aperture control in the surveillance camera shown in FIG. It is a figure for demonstrating the other example of the program diagram used by small aperture control in the surveillance camera shown in FIG. It is a block diagram which shows an example of the surveillance camera by the 2nd Embodiment of this invention with a client apparatus. It is a figure which shows an example of the arrangement | sequence in GUI shown in FIG. It is a figure for demonstrating an example of the operation part shown in FIG. It is a figure which shows an example of the display of the partial image which concerns on the cut-out area | region selected by the image cut-out position selection part shown in FIG. It is a flowchart for demonstrating an example of the image cut-out process performed with the surveillance camera shown in FIG. FIG. 11 is a diagram for describing an example of display of a partial image when four cutout areas are selected in the client device illustrated in FIG. 10. It is a figure which shows an example at the time of selecting one when the four partial images are displayed on the client apparatus shown in FIG. It is a figure which shows an example when a moving body is detected in one when the four partial images are displayed on the client apparatus shown in FIG.

  Hereinafter, an example of an imaging apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of an example of an imaging apparatus according to the first embodiment of the present invention.

  The illustrated imaging apparatus is, for example, a digital surveillance camera (hereinafter simply referred to as a surveillance camera) 1 and includes an imaging lens 100. The imaging lens 100 has a fixed focus. A diaphragm 101 is disposed at the rear stage of the imaging lens 100, and the diaphragm 101 adjusts the amount of light incident from the imaging lens 100. The aperture diameter of the diaphragm 101 is controlled by the diaphragm controller 102. The diaphragm 101 may be arranged at a predetermined position between a plurality of lenses constituting the imaging lens 100.

  An optical image (subject image) is formed on the imaging element 103 via the imaging lens 100. The image sensor 103 outputs an electrical signal (analog signal) corresponding to the optical image. The A / D conversion unit 103 A / D converts an analog signal that is an output of the image sensor 103 and outputs a digital signal.

  A digital signal that is an output of the A / D converter 104 is sent to the exposure controller 105. The exposure control unit 105 adjusts the aperture diameter of the diaphragm 101 by the diaphragm control unit 102 according to the luminance of the digital image signal. Further, the exposure control unit 105 may perform gain control for adjusting the amplification factor in accordance with the control of the exposure time and the signal level of the digital signal. That is, the exposure control unit 105 adjusts the exposure to a predetermined exposure for the digital signal.

  The image processing unit 106 performs image processing such as gamma correction, edge enhancement, noise reduction, and contrast adjustment on the digital signal output from the exposure control unit 105 to generate image data.

  The image cutout position calculation unit 107 obtains a distance (hereinafter referred to as a cutout distance) between the current image cutout position and the center of the effective area of the image sensor 103 in the image obtained as a result of shooting. Although not shown in FIG. 1, the image cutout position calculation unit 107 is provided with cutout information (also referred to as image cutout information) indicating the position of the cutout area from the client device via the network.

  The storage unit 109 stores an aperture value corresponding to the distance from the center of the effective area of the image sensor 103. The determination unit 108 refers to the storage unit 109 according to the cut-out distance, and determines whether or not the aperture 102 is to be a small aperture, as will be described later. The exposure control unit 105 controls the aperture diameter of the diaphragm 101 by the diaphragm control unit 102 according to the determination result by the determination unit 108.

  The image cutout unit 110 generates a partial image using an area specified by a cutout distance in image data (hereinafter also simply referred to as an image) that is output from the image processing unit 106. The image size changing unit 111 changes the size of the partial image output from the image cutout unit 110 in accordance with the size designation. Changing the image size includes enlargement and reduction, and is not particularly limited with respect to the aspect ratio. If no size is specified, the image size changing unit 111 does not change the image size of the partial image.

  The detection unit 112 performs a contrast evaluation value calculation, edge detection, motion vector detection, face detection, data amount calculation, and the like for the image whose size has been changed by the image size changing unit 111. Note that the detection unit 112 may perform the above processing and detection in accordance with the image data that is the output of the image processing unit 106. The image output unit 113 outputs a partial image that is an output unit of the image size changing unit 111.

  Although not shown in FIG. 1, the surveillance camera 1 includes a CPU (hereinafter referred to as a camera CPU) that controls the entire surveillance camera.

  FIG. 2 is a flowchart for explaining image cutout processing performed by the monitoring camera shown in FIG. Here, a case where one region is designated as a cutout region in an image obtained as a result of imaging (hereinafter referred to as a captured image) will be described.

  Now, when an image cutout designation is sent from a client device (not shown), the surveillance camera 1 starts an image cutout process. Then, the image cutout position calculation unit 107 acquires cutout information indicating the position of the cutout area in the captured image under the control of the camera CPU (step S100). The cutout information has a coordinate position indicating the position of the cutout area, and includes the number of cutout areas and the size (height and width) of the cutout area.

  Subsequently, the image cutout position calculation unit 107 obtains a cutout distance from the center of the effective area of the image sensor 103 to the image cutout position according to the cutout information (step S101).

  FIG. 3 is a diagram for explaining the calculation of the cutout distance performed by the image cutout position calculation unit 107 shown in FIG.

  In FIG. 3, the center coordinate of the effective area of the image sensor 103 is indicated by O (0, 0). The image cutout position, that is, the center coordinates of the cutout area A is indicated by A (x, y). In this case, the image cutout position calculation unit 107 calculates the cutout distance D using the following equation (1).

  When calculating the cutout distance, the distance between the reference coordinate and any one point in the cutout area may be set as the cutout distance with reference to any coordinate in the effective area of the image sensor 103 instead of the center coordinates. .

  The determination unit 108 determines whether the cutout distance D is equal to or greater than a predetermined distance under the control of the camera CPU (step S102). If the cut-out distance D is equal to or greater than the predetermined distance (YES in step S102), the determination unit 108 sends a small aperture command for setting the aperture 101 to the predetermined small aperture to the exposure control unit 105 (step S103). The exposure control unit 105 performs small aperture control according to the small aperture command. In the small aperture control, the exposure control unit 105 performs the exposure control using the exposure time and gain other than the aperture 101.

  In the small aperture control, the exposure control unit 105 controls the aperture value to the aperture value at which the contrast evaluation value in the partial image detected by the detection unit 112 is the highest or the aperture value at which the data amount of the partial image is the largest. To do.

  FIG. 4 is a diagram showing an example of the relationship between the diaphragm and the contrast evaluation value in the monitoring camera shown in FIG.

  In FIG. 4, generally, the depth of field becomes shallow when the aperture 101 is opened. For this reason, the peripheral portion of the captured image is easily blurred and the contrast evaluation value is lowered. On the other hand, when the aperture 101 is a small aperture, the depth of field becomes deep. For this reason, the peripheral portion of the captured image appears to be in focus, and the contrast evaluation value is higher than that in the case where the aperture is fully open.

  However, if the aperture 101 is made too small, a diffraction phenomenon occurs in the aperture 101 and the contrast evaluation value decreases. For this reason, in the small aperture control, the aperture value is set to the aperture value at which the contrast evaluation value is highest on the small aperture side.

  In the aperture control, an aperture value corresponding to the distance from the center of the effective area of the image sensor 103 may be used. One-side blur caused by the imaging lens 100, individual variation caused by the tilt of the image sensor 103, and the like. The aperture value may be determined in consideration of

  FIG. 5 is a diagram illustrating an example of an aperture value corresponding to the distance from the center of the effective area of the image sensor in the monitoring camera illustrated in FIG. 1.

  In the example illustrated in FIG. 5, the aperture value (F number) increases as the distance from the center or the center point (reference point) of the effective area of the image sensor 103 increases. The aperture values shown in FIG. 5 are stored in the storage unit 109 as a table, for example.

  FIG. 6 is a diagram illustrating an example of an aperture value based on the image height in the monitoring camera illustrated in FIG.

  In the example shown in FIG. 6, the aperture value (F number) is increased as the image height ratio increases for image heights up to 100% with reference to the image height of 0% in the imaging lens 100. The aperture values shown in FIG. 5 are stored in the storage unit 109 as a table, for example.

  FIG. 6 shows an example in which the image height ratio increases by 10%. However, at this time, other image height ratios may be obtained by interpolation. At this time, the aperture is made smaller as the image height becomes higher, but depending on the optical characteristics of the imaging lens 100, the aperture value may be arbitrarily changed depending on the image height.

  FIG. 7 is a diagram illustrating an example of an aperture value in consideration of individual variation of the image sensor in the monitoring camera illustrated in FIG.

  In FIG. 5 described above, the aperture value is determined only in accordance with the distance from the center of the effective area of the image sensor 103. On the other hand, FIG. 7 is used, for example, when there is a difference in image degradation and aberrations depending on the position where the image is cut out. Assume that the upper left, upper right, lower left, and lower right of the image are affected by image degradation and aberration. In this case, as shown in FIG. 7, the aperture value is determined according to the distance from the center of the effective area of the image sensor 103, but the upper left, upper right, lower left, and lower right of the image are taken into consideration in consideration of the cutout position of the image. To change the aperture value. The aperture values shown in FIG. 7 are stored in the storage unit 109 as a table.

  Referring to FIG. 2 again, when cutout distance D is less than the predetermined distance (NO in step S102), determination unit 108 issues a command to perform exposure control using the currently set exposure control method. Sent to 105. Thus, the exposure control unit 105 performs normal exposure control (step S104). Thereafter, the camera CPU ends the image cutout process.

  Here, the exposure control methods include, for example, full auto exposure control, exposure time priority control, manual exposure control, and aperture priority control. The above-described small aperture exposure control corresponds to aperture priority control. The aperture value at the time of the small aperture control is not set as a fixed value, and for example, a restriction may be provided on the aperture control range or the small aperture side on the program diagram.

  FIG. 8 is a diagram for explaining an example of a program diagram used for small aperture control in the monitoring camera shown in FIG. 1.

  In FIG. 8, the lower horizontal axis indicates the exposure time, and here, the exposure time becomes shorter toward the right side. The vertical axis on the right side shows the aperture value, and the aperture value becomes smaller toward the upper side. Both the left vertical axis and the upper horizontal axis correspond to the exposure amount (hereinafter, EV value), and the EV value increases toward the upper right.

  Assume that a program diagram indicated by a solid line is set. If the cutout distance (calculated distance) D is equal to or greater than a predetermined distance, a program diagram indicated by a broken line is used in the process of step S103. Here, regardless of the EV value, the aperture value in the small aperture control is fixed, and the exposure control is performed by the exposure time and gain other than the aperture.

  On the other hand, in the program diagram shown in FIG. 8, when the EV value is low, the aperture cannot be opened and sufficient exposure may not be obtained. Therefore, the exposure control unit 105 determines whether or not the EV value is equal to or less than a predetermined EV value (step S105).

  FIG. 9 is a diagram for explaining another example of a program diagram used for small aperture control in the monitoring camera shown in FIG.

  In FIG. 9, the program diagram indicated by the solid line is the same as the program diagram indicated by the solid line in FIG. In the program diagram indicated by the broken line, the EV value increases as the exposure time becomes shorter from the long second exposure, and the EV value becomes constant (predetermined EV value) after the predetermined exposure time. The exposure control unit 105 determines whether or not the EV value is equal to or less than the predetermined EV value. If the EV value is equal to or less than the predetermined EV value (YES in step S105), the exposure control unit 105 increases the upper limit to the small aperture side. Is set (step S106). Thus, when the EV value is low, an upper limit is set when the diaphragm 101 is controlled to the small diaphragm side, so that a situation in which sufficient exposure cannot be obtained can be prevented. Thereafter, the camera CPU ends the image cutout process.

  On the other hand, when the EV value exceeds the predetermined EV value (NO in step S105), the camera CPU ends the image clipping process.

  As described above, in the first embodiment of the present invention, since the exposure control is changed according to the distance between the cutout position and the center of the effective area of the image sensor, the image is cut out when the partial image is cut out from the captured image. Regardless of the position of the region, it is possible to perform clipping while suppressing deterioration in image quality.

[Second Embodiment]
Next, an example of a surveillance camera according to the second embodiment of the present invention will be described.

  FIG. 10 is a block diagram showing an example of a surveillance camera according to the second embodiment of the present invention together with a client device. In FIG. 10, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  As illustrated, a client device (external device) 2 is connected to the monitoring camera 1 via a network or the like. The client device 2 includes a graphic user interface (GUI), and the GUI includes a display unit 201, an operation unit 202, and an image cutout position selection unit 203. The image cutout position selection unit 203 is connected to the image cutout position calculation unit 107, and the display unit 201 is connected to the image output unit 113.

  In FIG. 10, a control system such as a CPU provided in the client device 2 is omitted. In the following description, the CPU provided in the client device 2 is referred to as a client CPU.

  FIG. 11 is a diagram showing an example of an arrangement in the GUI shown in FIG.

  As illustrated, a captured image is displayed on the display unit 201, and an image having a size smaller than that of the captured image displayed on the display unit 201 is displayed on the image cut-out position selection unit 203. Then, a cross indicating the center is displayed on the image cutout position selection unit 203. An operation unit 202 is arranged on the right side of the image cutout position selection unit 203 and the display unit 201.

  In the illustrated example, the monitoring camera 1 is connected to the client device 2 via a network. However, the monitoring camera 1 may be directly connected to the client device 2 by a cable or the like. The client device 2 may communicate with a plurality of monitoring cameras 1 via a network.

  The user operates the operation unit 202 while viewing the image displayed on the display unit 201 and designates a region to be cut out in the captured image. Here, the user designates a cutout area in the image displayed on the image cutout position selection unit 203 by using a pointing device such as a mouse provided in the operation unit 202. As a result, the client CPU sends the position (cutout position) of the cutout area selected by the image cutout position selection unit 203 to the image cutout position calculation unit 107.

  FIG. 12 is a diagram for explaining an example of the operation unit 202 illustrated in FIG. 10.

  The operation unit 202 is provided with a plurality of cutout area designation fields for designating cutout areas. In the cutout area designation field, cutout areas “1”, “2”, and so on can be designated. In the cutout area designation field, the X coordinate, the Y coordinate, the height, which are information for specifying the cutout area, An input field for inputting the width is also provided.

  In the following description, a case is described in which a rectangular area is designated as the cutout area. However, the cutout area is not limited to a rectangle, and may be a polygon or a circle.

  FIG. 13 is a diagram illustrating an example of display of a partial image related to the cutout region selected by the image cutout position selection unit 203 illustrated in FIG. 10.

  Now, it is assumed that the user uses the operation unit 202 to select the position of a desired cutout area (in the illustrated example, a human face) as the designated cutout position in the image cutout position selection unit 203. As a result, the client CPU sends the designated cutout position selected by the image cutout position selection unit 203 to the image cutout position calculation unit 107 of the monitoring camera 1.

  As described above, the image cutout unit 110 cuts out the cutout region specified by the cutout position calculated by the image cutout position calculation unit 107 from the captured image to obtain a partial image. The image size changing unit 111 enlarges the partial image to obtain an enlarged partial image (that is, the image size changing unit 111 enlarges the partial image according to the screen size of the display unit 201). The enlarged partial image is sent from the image output unit 113 to the client device 2, and the client CPU displays the enlarged partial image on the display unit 201.

  As a result, the face of the person is enlarged and displayed on the display unit 201 as shown in FIG.

  When displaying the partial image on the display unit 201, the image processing unit 106 may perform the distortion correction processing of the imaging lens 100, and further, the client device performs the partial image correction processing. You may do it.

  FIG. 14 is a flowchart for explaining an example of the image cut-out process performed by the monitoring camera shown in FIG.

  In FIG. 14, the same steps as those in the flowchart shown in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted. Here, a case will be described in which a plurality of areas are designated as cutout areas by the image cutout position selection unit 203 in the client device 2.

  In the monitoring camera 1, the image cutout position calculation unit 107 acquires cutout region information indicating the image cutout position for each of the regions selected by the image cutout position selection unit 203 (step S200). In addition to the coordinates of each cutout area, the number of cutout areas, and the height and width of each cutout area, the cutout area information may include a display form when displayed on the display unit 201.

  Subsequently, the image cutout position calculating unit 107 obtains a cutout distance D from the center of the effective area of the image sensor 103 to the image cutout position for each cutout area according to each piece of cutout position information (step S201). In step S102, the determination unit 108 determines whether the cutout distance D is equal to or greater than a predetermined distance for each cutout region.

  If cut-out distance D is less than the predetermined distance (NO in step S102), determination unit 108 sends to exposure control unit 105 a command to maintain the current exposure control. Thereby, the exposure control unit 105 maintains the current exposure control (step S203). Thereafter, the camera CPU ends the image cutout process.

  When the cut-out distance D is equal to or greater than the predetermined distance (YES in step S102), the determination unit 108 sends a small aperture command for setting the aperture 101 to the predetermined small aperture to the exposure control unit 105. As a result, the exposure control unit 105 performs small aperture control in accordance with the small aperture command in step S103 as described in the first embodiment. At this time, the exposure control unit 105 performs the clipping. Exposure control is performed on the cutout region with the longest distance D.

  FIG. 15 is a diagram for explaining an example of partial image display when four cutout regions are selected in the client device 2 illustrated in FIG. 10.

  As described above, in the client device 2, four cutout areas are selected by the image cutout position selection unit 203. In this case, four partial images are displayed on the display unit 201 via the image cutout unit 110, the image size changing unit 111, and the image output unit 113.

  Here, in order to display four partial images on the display unit 201, the image size changing unit 111 divides the screen size of the display unit 201 into four equal parts, and performs enlargement or reduction processing to display the partial image in each display area. . In the client apparatus 2, the CPU displays the numbers “1” to “4” superimposed on the partial images displayed in four divisions.

  Here, an example in which four clip areas are selected in the client device 2 has been described. However, when two or more clip areas are selected, the display screen of the display unit 201 is similarly divided. A partial image is displayed.

  Referring to FIG. 14 again, the camera CPU determines whether any of the partial images displayed on display unit 201 has been selected by a user operation (step S205).

  FIG. 16 is a diagram illustrating an example when one of four partial images is displayed on the client device 2 illustrated in FIG. 10.

  Here, the user moves the cursor to the partial image with the number “2” using the pointing device provided in the operation unit 202 and selects the partial image with the number “2”. When selecting a partial image, the cursor is moved to a desired partial image by a pointing device and then a button provided on the operation unit 202 is operated to select the partial image with the cursor. Alternatively, the partial image may be selected when the cursor is moved to a desired partial image for a predetermined time.

  If none of the partial images is selected by the user operation even after the preset time has elapsed (NO in step S205), the determination unit 108 determines whether the partial image (that is, the cutout region) is under the control of the camera CPU. A command for performing exposure control is sent to the exposure control unit 105 so that the partial image with the longest cutout distance D has an optimum aperture value (here, F value). Then, the exposure control unit 105 performs the exposure control unit so that the F value is optimal for the cutout region corresponding to the partial image with the longest cutout distance D (step S206).

  On the other hand, when any of the partial images is selected by the user operation (YES in step S205), the determination unit 108 determines that the aperture value (F value) is optimal for the selected partial image under the control of the camera CPU. A command for performing exposure control is sent to the exposure control unit 105. Then, the exposure control unit 105 performs exposure control so that the F value is optimized with respect to the cutout region corresponding to the selected partial image (step S207).

  After the process of step S206 or S207, the camera CPU determines whether a moving object is detected in the plurality of partial images by the detection unit 112 or whether there is a partial image (step S208).

  FIG. 17 is a diagram illustrating an example when a moving object is detected in one of the four partial images displayed on the client device 2 illustrated in FIG. 10.

  Here, a moving object is detected in the partial image (person) indicated by the number “4”. When a moving object is detected, the client CPU displays an arrow indicating the moving direction of the moving object superimposed on the partial image. To do.

  If there is a partial image in which a moving object is detected (YES in step S208), exposure control unit 105 causes the F value to be optimal with respect to a cutout region corresponding to the partial image in which the moving object is detected under the control of camera CPU. Then, exposure control is performed (step S209). Thereafter, the camera CPU ends the image cutout process.

  On the other hand, if no moving object is detected in any of the partial images (NO in step S208), the camera CPU ends the image clipping process.

  When moving objects are detected, the subject is a person or a car, but in order to carry away items or monitor suspicious persons, whether or not a specific event has occurred in addition to or instead of moving objects is detected. May be detected. Furthermore, when the partial image in which the moving object is detected is different from the partial image selected by the user, the user determines the priority order. At this time, processing may be performed according to a predetermined priority order.

  As described above, in the second embodiment of the present invention, when a plurality of partial images are cut out from the captured image and displayed, the exposure control is performed with respect to the cut-out area corresponding to the partial image selected by the user. As a result, the user can monitor the partial image to be monitored clearly.

  Furthermore, since exposure control is performed for a cutout region corresponding to a partial image in which a predetermined event such as detection of a moving object has occurred, the user can better monitor the partial image in which the event has occurred.

  As is clear from the above description, in the example shown in FIGS. 1 and 10, the image processing unit 106, the image clipping unit 110, the image size changing unit 111, and the image output unit 113 function as a clipping unit, and image clipping is performed. The position calculation unit 107, the determination unit 108, the exposure control unit 105, and the aperture control unit 102 function as a control unit. Further, the client CPU and the display unit 201 function as a display unit, and the client CPU, the image cutout position selection unit 203, and the operation unit 202 function as a selection unit. Further, the client CPU functions as a transmission unit.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to these embodiment, Various forms of the range which does not deviate from the summary of this invention are also contained in this invention. .

  Moreover, what is necessary is just to make an imaging device perform this control method by using the function of said embodiment as a control method. Further, a program having the functions of the above-described embodiments may be used as a control program, and the control program may be executed by a computer included in the imaging apparatus. The control program is recorded on a computer-readable recording medium, for example.

[Other Embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 101 Diaphragm 103 Image pick-up element 105 Exposure control part 106 Image processing part 107 Image clipping position calculation part 108 Judgment part 110 Image clipping part 111 Image size changing part 112 Detection part 113 Image output part

Claims (16)

An imaging apparatus including an imaging element that forms an optical image through an imaging lens and a diaphragm and outputs an image corresponding to the optical image,
Cutting means for cutting out a cut-out area specified in the image as a partial image;
Control means for performing exposure control by adjusting the diaphragm according to the position of the cutout region in the image;
An imaging device comprising:   The control means obtains a distance between a position in the image of the cutout area in the image and a reference point preset in the effective area of the imaging element as a cutout distance, and when the cutout distance is equal to or greater than a predetermined distance, The imaging apparatus according to claim 1, wherein exposure control is performed using the diaphragm as a predetermined diaphragm value.   The imaging apparatus according to claim 2, wherein the reference point is a center point of the effective area.   The imaging apparatus according to claim 2, wherein the predetermined aperture value is an aperture value in which the aperture is a small aperture.   The aperture value at which the aperture is a small aperture is an aperture value at which the contrast evaluation value in the partial image is the highest, or an aperture value at which the data amount in the partial image is the largest. Imaging device.   The imaging apparatus according to claim 1, further comprising a storage unit that stores an aperture value corresponding to the cut-out distance.   When performing the exposure control based on a preset program diagram, the control means sets an upper limit for the aperture value when the EV value is equal to or smaller than a predetermined EV value when the aperture value is set to a small aperture value. The imaging apparatus according to claim 1, wherein:   The imaging apparatus according to claim 1, wherein the control unit performs the exposure control using an image height of the cutout region in the imaging lens as a position in the image.   The imaging apparatus according to claim 8, further comprising a storage unit that stores an aperture value corresponding to the image height.   10. The imaging according to claim 2, wherein, when there are a plurality of designated cutout areas, the control unit performs the exposure control on a cutout area having the longest cutout distance. 10. apparatus.   When a predetermined event occurs in the partial image when there are a plurality of the specified cutout regions, the control means performs the exposure control on the cutout region corresponding to the partial image in which the event has occurred. The imaging apparatus according to claim 1, wherein the imaging apparatus is characterized. The imaging device is connected to an external device that receives the image,
Display means for displaying the image and the partial image on the external device, selection means for selecting the cutout area from the image displayed on the display means, and a cutout area selected by the selection means The imaging apparatus according to claim 1, further comprising: a transmission unit that sends the designated cutout area to the imaging apparatus.   When one of the partial images displayed on the display unit is selected by the selection unit, the transmission unit issues a command to perform the exposure control with respect to a cutout region corresponding to the selected partial image. The imaging apparatus according to claim 12, wherein   When a predetermined event occurs in the partial image when there are a plurality of designated cutout areas, one of the partial images is selected by the selection unit, and the selected partial image and the event are 14. The imaging apparatus according to claim 13, wherein when the generated partial image is different, the control unit performs the exposure control according to a preset priority order. A control method of an imaging apparatus including an imaging element that forms an optical image through an imaging lens and a diaphragm and outputs an image corresponding to the optical image,
A cutout step of cutting out a cutout area specified in the image as a partial image;
A control step of performing exposure control by adjusting the diaphragm according to the position of the cutout region in the image;
A control method characterized by comprising: A control program used in an imaging apparatus including an imaging element that forms an optical image through an imaging lens and a diaphragm and outputs an image corresponding to the optical image,
In the computer provided in the imaging device,
A cutout step of cutting out a cutout area specified in the image as a partial image;
A control step of performing exposure control by adjusting the diaphragm according to the position of the cutout region in the image;
A control program characterized by causing