JP7412940B2 - Imaging device, computer program and storage medium - Google Patents

Description

The present invention relates to an imaging device, a computer program, and a storage medium.

2. Description of the Related Art An imaging device equipped with a light has been proposed in order to capture images by irradiating light such as an infrared LED in a low-light environment such as at night (Patent Document 1).

Japanese Patent Application Publication No. 2005-94080

However, in the imaging device disclosed in Patent Document 1, the imaging section and the illumination section cannot be arranged coaxially, so the center of the illumination cannot illuminate the center of the desired photographic screen during photographing. Therefore, the peripheral area of the photographing screen on the side far from the center of the illumination becomes dark, and appropriate photographing may not be possible. In particular, as the shooting angle of the imaging device approaches the horizontal direction to take pictures of distant objects, the center of the illumination moves away from the center of the shooting screen, and the brightness of the peripheral area of the shooting screen on the side far from the center of the lighting becomes darker. , image visibility decreases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the visibility of a photographed image by illuminating a designated photographing range over a wider area while suppressing a decrease in illuminance in an imaging device having an illumination section.

In order to solve the above problems, an imaging device of the present invention includes an imaging section, an illumination section arranged such that the optical axis is different from that of the imaging section, and a drive unit capable of driving the imaging section and the illumination section integrally. The control unit includes a drive unit, a view angle change unit capable of changing the shooting angle of view of the imaging unit , and a control unit that controls the view angle change unit and the drive unit, and the control unit is configured to control the illumination unit. When the light is on, the distance on the photographed image between the center point of the specified photographing range and a high brightness point having a luminance equal to or higher than a predetermined value in the range illuminated by the illumination section is set to be less than a threshold value. the driving section is driven, and the angle of view changing section is controlled to widen the photographing angle of view according to the amount by which the driving section is driven, and the photographed image is widened according to the amount by which the driving section is driven. The present invention is characterized in that an image within the designated photographing range is cut out from a photographic image photographed at a corner.

According to the present invention, in an imaging device having an illumination section, it is possible to suppress a decrease in illuminance, illuminate a designated photographing range over a wider range, and improve the visibility of a photographed image.

1 is a diagram illustrating an imaging system including an imaging device according to an embodiment. FIG. 2 is a schematic diagram showing an example of the arrangement of an imaging section and an illumination section. FIG. 2 is a block diagram showing the internal structure of a signal processing section. FIG. 2 is a schematic diagram showing an example of a usage state of the imaging device. 5 is a schematic diagram of a photographic screen photographed in the usage state of FIG. 4. FIG. 12 is a flowchart showing processing according to the second embodiment. FIG. 7 is a diagram illustrating processing according to a second embodiment. FIG. 7 is a diagram illustrating processing according to a third embodiment. 12 is a flowchart illustrating processing according to Example 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An imaging device according to an embodiment of the present invention will be described below with reference to the drawings. In this case, parts having the same functions in the figures are given the same numbers, and repeated explanations thereof will be omitted. In the embodiment, an example in which the present invention is applied to a network camera as an imaging device will be described.

(Example 1)
FIG. 1 is a diagram illustrating an imaging system 1000 including an imaging device 100 according to this embodiment. FIG. 1A is a schematic diagram showing the configuration of an imaging system 1000 including an imaging device 100 according to this embodiment. The imaging system 1000 includes an imaging device 100 and a client device 170 that can communicate with the imaging device 100 via a network 160. The network 160 is configured by, for example, a wired LAN, a wireless LAN, or the like. The imaging device 100 includes an imaging illumination section 110, a driving section 120, a signal processing section 130, a photographing angle acquisition section 140, and a user interface 150.

The imaging illumination section 110 includes an imaging section 111 and an illumination section 113. The imaging unit 111 includes, for example, a lens that collects reflected light from a subject surface illuminated by the illumination unit 113, and an imaging element that converts the reflected light into an electrical signal. The imaging unit 111 includes an optical zoom unit 112 (field angle changing unit) for changing the imaging magnification. The optical zoom unit 112 can change the photographing angle of view by driving and controlling a variable magnification lens using a zoom motor, for example.

The lighting section 113 includes lighting elements such as LEDs, and can turn on and off the lighting and change the light distribution angle of the lighting in accordance with a control signal from the signal processing section 130. Here, changing the light distribution angle means changing the irradiation range by, for example, moving a lens provided in front of the lighting element in the optical axis direction to change the spread of light from the lighting section 113. The smaller the light distribution angle and the narrower the irradiation range, the more the amount of light within the irradiation range of the illumination unit 113 can be increased. Note that when the illumination unit 113 does not include a lens, the central axis of the light emitted by the illumination unit 113 is defined as the optical axis.

The driving unit 120 can drive the imaging unit 111 and the illumination unit 113 coaxially based on a control signal from the signal processing unit 130. Details of the drive unit 120 will be described later.

The signal processing unit 130 is connected to an external device (client device 170) such as a PC or a monitor via a network 160, for example. For example, the signal processing unit 130 transmits a video signal to the client device 170 and causes the client device 170 to display a captured image. Note that the signal processing section 130 has a built-in CPU as a computer, and functions as a control means for executing various operations of the entire apparatus based on a computer program stored in a memory (not shown).

User interface 150 is used by the user to specify a specified range. The user interface 150 allows the user to specify the shooting range. User interface 150 includes various switches, a touch panel, and the like. Furthermore, it may include a GUI (graphical user interface) such as buttons and icons displayed on the display unit 173 of the client device 170. The user interface 150 may be placed not on the imaging device 100 side but on the client device 170 side.

The photographing angle acquisition unit 140 acquires the photographing angle of the imaging device. Details of the photographing angle will be described later. The photographing angle acquisition unit 140 is, for example, an electronic level, and can electrically measure the angle. The shooting angle may be input by the user using the user interface 150.

The client device 170 is, for example, an external device such as a PC (personal computer) or a tablet terminal. For example, the client device 170 transmits a command to control the imaging device 100 to the imaging device 100 via the network 160. In response, the imaging device 100 returns a response to the command to the client device 170. The command is, for example, control of the imaging illumination section 110 or the drive section 120.

The client device 170 can include a control section 171, an input section 172, and a display section 173. The control unit 171 controls the inside of the client device 170 and includes a built-in computer such as a CPU. Further, the control unit 171 includes a built-in memory (not shown), and the memory stores a computer program for controlling the operation of the CPU in the control unit. The control unit 171 also functions as a display control unit (display control unit) that causes the display unit 173 to display an image including the user interface 150 for the user to specify a shooting range.

The display unit 173 is for displaying video signals sent from the imaging device 100, and is, for example, a display device such as a liquid crystal display panel, a plasma display panel, or an organic EL (Electro Luminescence) display panel. For example, the user can issue various instructions to the imaging device 100 by operating the user interface 150 using the input unit 172.

The input unit 172 is, for example, a touch panel, keyboard, mouse, or the like that receives operation input from the user, and receives instructions and input from the user using the touch panel or keys. Note that when the client device 170 is a tablet terminal, the input section 172 also functions as the display section 173, and the display section 173 and the input section 172 may have an integrated structure.

FIG. 1B shows an example of a method for specifying a shooting range using the user interface 150. Here, it is assumed that the default setting of the imaging range of the imaging device 100 is the imaging range 205, and that the imaging range 205 is displayed on the client device 170. When the user specifies a desired photographing range 206 from the displayed photographing range 205, the optical zoom unit 112 and drive unit 120 are controlled to correspond to the photographing range 206, and the photographing range 206 is displayed. Here, the photographing range 206 is a specified photographing range.

FIG. 2 is a schematic diagram showing an example of the arrangement of the imaging section 111 and the illumination section 113. In this figure, the x, y, and z axes that are perpendicular to each other are taken as shown in FIG. 2 for the imaging device 100 installed on the ceiling surface 201. Here, point O indicates the origin of the xyz axes, and indicates the origin of the drive shaft of the drive unit 120. 2(A) shows a configuration in which the imaging unit 111 and the illumination unit 113 are arranged in the y-axis direction, and FIG. 2(B) shows the configuration in which the imaging unit 111 and the illumination unit 113 are arranged in the x-axis direction. The respective configurations when arranged are shown below. A broken line 203 indicates the optical axis of the imaging unit 111, and a broken line 204 indicates the optical axis of the illumination unit 113. In both FIGS. are arranged coaxially so that they do not overlap. In other words, the imaging section 111 and the illumination section 113 are arranged so that their optical axes are different from each other. As shown in FIG. 2A, when the imaging unit 111 and the illumination unit 113 are arranged side by side in the y-axis direction, the driving unit 120 rotates at least the imaging illumination unit 110 with respect to the x-axis. It has a uniaxial drive mechanism. As shown in FIG. 2B, when the imaging unit 111 and the illumination unit 113 are arranged side by side in the x-axis direction, the driving unit 120 rotates at least the imaging illumination unit 110 with respect to the y-axis. It has a uniaxial drive mechanism.

Here, the photographing angle acquired by the photographing angle acquisition section 140 will be explained. The photographing angle is the angle formed by the y-axis and the optical axis of the imaging unit 111 in FIG.

FIG. 3 is a block diagram showing the internal structure of the signal processing section 130. The signal processing section 130 includes an image processing section 310, a control section 320, a calculation section 330, and a storage section 340. The signal processing section 130 performs correction processing and development processing on the electrical signal converted by the imaging section 111 in the image processing section 310, and outputs a processed video signal. The image processing unit 310 includes a brightness acquisition unit 311, and the brightness acquisition unit 311 can acquire brightness information of a captured image.

The storage unit 340 stores the installation height of the imaging device 100 input by the user. The installation height refers to the distance OH between a perpendicular line drawn from point O to the subject plane 202 and the intersection H with the subject plane in FIG. 2 . Note that the method for obtaining the installation height is not limited to user input. For example, if the imaging device has a focus lens for adjusting the focus plane, by evaluating the resolution of the image while wobbling the focus lens along the optical axis of the lens, it is possible to adjust the focus when the focus plane matches point H. It may be calculated by finding the distance to the surface.

Based on the brightness information acquired by the brightness acquisition unit 311, the calculation unit 330 calculates, in particular, the control amount of the drive unit 120, in other words, the amount by which the drive unit 120 is driven (drive amount). Details will be described later.

The control unit 320 includes an imaging control unit 321, an illumination control unit 322, and a drive control unit 323. The control unit 320 controls the imaging unit 111, the illumination unit 113, and the drive unit 120, respectively, based on the control amount calculated by the calculation unit 330. The imaging control section 321 controls the imaging section 111 including the optical zoom section 112. The lighting control section 322 controls the lighting section 113. The drive control section 323 controls the drive section 120.

FIG. 4 is a schematic diagram showing an example of a usage state of the imaging device 100. Further, FIG. 5 is a schematic diagram of a photographing screen photographed in the usage state of FIG. 4. As an example, the imaging device 100 shown in FIG. 4 has an imaging unit 111 and an illumination unit 113 arranged so as to be lined up in the y-axis direction as shown in FIG. Assume something that can be driven. Further, it is assumed that the optical axis of the imaging section 111 and the optical axis of the illumination section 113 are parallel, and these optical axes are perpendicular to the imaging surface of the imaging section 111 of the imaging illumination section 110.

FIG. 4A is a schematic diagram showing a case where, when the illumination unit 113 is turned on, a designated photographing range 401 is photographed in accordance with the photographing angle of view. In FIG. 4A, the imaging device 100 is installed on a ceiling surface 201 and photographs a subject surface 202 that is horizontal to the ceiling surface 201 at a photographing angle θ ₁ . Point A ₀ indicates a point on the optical axis of illumination section 113 , and point B ₀ indicates a point on the optical axis of imaging section 111 . It is assumed that point O, point A ₀ , and point B ₀ are on the same straight line. Point A ₁ indicates a high-intensity point of illumination on the subject plane 202, and point B ₁ indicates the center point of the angle of view in the photographing range (hereinafter referred to as point of interest B ₁ ). Here, the high brightness point refers to a point within the range illuminated by the illumination unit 113 that has a brightness equal to or higher than a predetermined value. The angle α ₁ indicates the light distribution angle of the illumination, and the angle β ₁ indicates the angle of view. A schematic diagram of the photographing screen photographed in FIG. 4(A) is shown in FIG. 5(A). A white range 501 indicates an illumination range. As shown in FIG. 5(A), when shooting by adjusting the shooting angle of view to the specified shooting range 401, the high brightness point _A1 is in front of the point of interest _B1 , so the point of interest _B1 is The surrounding area cannot be illuminated with sufficient illuminance. Therefore, in an environment with insufficient illuminance, such as at night, a dark area with poor visibility can become large.

On the other hand, in this embodiment, a high-brightness point A ₁ of illumination is brought close to the vicinity of the point of interest B ₁ and photographed. FIG. 4(B) is a schematic diagram of an example of use of the imaging device according to this embodiment, and FIG. 5(B) shows a captured image in the case of FIG. 4(B). The imaging illumination unit 110 is driven by the drive unit 120 by the drive angle γ so that the point of interest B ₁ is illuminated by the high-intensity point A ₁ of the illumination, or in other words _, the point of interest B ₁ and the high-intensity point A 1 approach each other. and shoot at a shooting angle of θ ₂ . Specifically, the driving unit 120 is driven so that the distance (distance A ₁ B ₁ ) between the point of interest B ₁ and the high-intensity point A ₁ on the photographed image is less than a threshold value. The distance A ₁ B ₁ can be obtained, for example, based on the number of pixels of the captured image and the distance OA ₁ . Further, at this time, it is preferable to drive the driving unit 120 so that the point of interest B ₁ and the high brightness point A ₁ overlap. When the imaging illumination unit 110 is driven so that the point of interest B ₁ and the high brightness point A ₁ approach each other, the angle of view shifts from the specified shooting range 401 to the specified shooting range 502 as shown in FIG. 5(B). , it is not possible to photograph point of interest _B1 . Therefore, the signal processing unit 130 widens the angle of view of the imaging unit 111 to the angle of view β ₂ so that the specified imaging range 401 falls within the angle of view, and photographs in the imaging range 503.

As described above, in an imaging device that does not individually control the direction of the illumination section 113 and the direction of the imaging section 111, by illuminating the center of the user-specified shooting range so that the center of the illumination hits the center of the shooting range specified by the user, the entire shooting range specified by the user can be illuminated. It becomes possible to take bright pictures.

In conventional imaging devices, the light distribution angle of the illumination section is adjusted according to the angle of view, such that when the angle of view is wide, the light distribution angle of the illumination section is widened, and when the angle of view is narrow, the light distribution angle of the illumination section is narrowed. Ta. That is, when photographing a designated photographing range 401 as shown in FIG. 5A, irradiation is performed at a light distribution angle corresponding to the angle of view of the photographing range 401. Therefore, when the angle of view is widened to include the shooting range 401 in the angle of view as in the present case so that shooting can be performed within the shooting range 503, the conventional method The light distribution angle is widened to correspond to the irradiation. However, in this case, what is originally desired to be photographed is the photographing range 401, and if the irradiation range 501 is expanded to match the photographing range 503, the amount of light will decrease relative to the photographing range 401. In this case, since it is sufficient to illuminate the photographing range 401, it is desirable that the light distribution angle is fixed at _α1 , that is, the light distribution angle is not changed. That is, according to the present embodiment, photography can be performed without reducing the amount of light in the photography range designated by the user.

Note that the arrangement configuration of the imaging unit 111 and the illumination unit 113 does not need to be arranged in line with the y-axis, nor does it need to be arranged symmetrically with respect to the origin O. Further, the optical axis of the imaging unit 111 and the optical axis of the illumination unit 113 do not need to be parallel, and any configuration is possible as long as they are coaxial and not coincident. According to this embodiment, there is no need to control the light distribution angle of the illumination unit 113. Furthermore, it is preferable that the signal processing unit 130 sets the brightest point in the captured image as a high-luminance point based on the luminance information of the captured image acquired by the luminance acquisition unit 311. By setting the brightest point as a high-intensity point, visibility of the shooting range is further improved. Furthermore, there may be a plurality of lights, and in this case, the brightness acquisition unit 311 detects a high brightness point when illuminated by the plurality of lights, and controls the imaging illumination unit 110 so as to approach the center of the photographing range 401.

Further, the method of determining the installation height is not limited to wobbling, and a distance measuring sensor may be used. The video signal transmitted from the signal processing section 130 may be stored in the storage section 340 of the imaging device 100 or may be stored on the client device 170 side. When the zoom magnification of the optical zoom unit 112 is reduced to widen the photographing angle of view, the deviation between the center point of the photographing range and the high brightness point of the illumination becomes small, so it is not necessary to perform illumination center photographing. Alternatively, the determination may be made based on the deviation between the center point of the photographing range and the high-brightness point of the illumination.

The offset direction of the imaging device 100 is arbitrary, and the imaging device 100 may face a direction rotated by an arbitrary angle in any of the x-axis, y-axis, and z-axis. The imaging device 100 may be installed not only on the ceiling but also on a wall or stationary. This also holds true even when the subject surface is not horizontal.

(Example 2)
In the first embodiment, only the illumination-centered photographing method is described in which a high-brightness point of illumination is brought close to the center (point of interest) of the photographing range specified by the user, and photographing is performed in which the angle of view is widened accordingly. In the second embodiment, a case will be described in which two methods are used, including conventional field-angle centered imaging, that is, a method in which imaging is performed without bringing the point of interest and a high-luminance point close together in a designated imaging range. That is, in this embodiment, the signal processing unit 130 can select whether or not to perform illumination center photography.

FIG. 6 is a flowchart showing processing according to the second embodiment. Each operation (step) shown in this flowchart can be executed by the signal processing unit 130.
(S601) The user inputs the installation height of the imaging device 100 using, for example, the input unit 172, and the storage unit 340 stores the installation height of the imaging device 100. The user also specifies a shooting range and proceeds to S602.

(S602) The signal processing unit 130 selects whether or not to perform illumination center photography. Here, if illumination center photography is selected (Yes), the process advances to S603. If illumination center photography is not selected (No), S602 is repeated.

(S603) The photographing angle θ ₁ of the imaging device 100 is read from the photographing angle acquisition unit 140, and the process proceeds to S604.

(S604) The brightness acquisition unit 311 acquires the high brightness point A ₁ of illumination from the photographed image, and the process advances to S605.

(S605) The signal processing unit 130 determines whether or not the high brightness point A ₁ and the point of interest B ₁ are close to each other. FIG. 7 is a diagram illustrating processing according to the second embodiment. If the difference 703 between the angle 701 between the line segment OA ₁ and the line segment OH and the angle 702 between the line segment OB ₁ and the line segment OH is less than the threshold value φ, the amount of light illuminating the point of interest B ₁ is sufficient, in other words. , it is determined that the point of interest B ₁ is illuminated by the illumination unit 113, and the process ends . On the other hand, if the difference 703 is greater than or equal to the threshold value φ, it is determined that the amount of light illuminating the point of interest B ₁ is insufficient, in other words, the point of interest B ₁ is not illuminated by the illumination unit 113, and the process proceeds to S606. . Here, the difference 703 can be said to be the distance between the high brightness point A ₁ and the point of interest B ₁ on the photographed image.

式（１）を用いて、おおよその値を算出することで、Ｓ６０６を繰り返す回数を低減することができる。 (S606) The drive control unit 323 drives the imaging illumination unit 110 by the drive angle γ ₁ and proceeds to S607. The driving angle γ ₁ may be the minimum step of the driving unit 120, or the driving angle may be made smaller as the number of repetitions of S606 increases by driving several steps at first. In addition, the approximate value is calculated using the following formula (1) obtained from the installation height OH, the photographing angle θ ₁ , and the distance A ₁ B ₁ between the high brightness point A ₁ and the point of interest B ₁ , and the drive angle γ ₁ may be determined. The distance A ₁ B ₁ can be calculated using the number of pixels of the photographic screen and the distance OA ₁ .

By calculating an approximate value using equation (1), the number of times S606 is repeated can be reduced.

(S607) The imaging control unit 321 controls the optical zoom unit 112 to widen the imaging angle of view according to the amount by which the driving unit 120 is driven (here, the driving angle γ ₁ ), and changes the imaging angle of view to the angle of view. The angle of view is changed from β ₁ to β ₂ (=β ₁ +2×γ ₁ ), and the process returns to S604. In S605, S604 to S607 are repeated until the difference 703 becomes less than the threshold value φ.

Here, the method of matching the high-brightness point of the illumination to the point of interest _B1 has been described, but the image processing unit 310 may also cut out the photographing range 401 and display it on the display screen. By cutting out and displaying the photographing range 401, it becomes possible to display the photographed image at a photographing angle of view that matches the specified photographing range, and it is possible to display the photographed image desired by the user.

Further, the selection of illumination-centered photography and field-angle-centered photography in this case in FIG. 6 (S602) may be performed automatically or manually by the user by providing a UI (user interface) on the viewer. There are several possible conditions for automatically selecting illumination center photography. First, there is a method in which the signal processing unit 130 selects field-angle center photography when it detects that the infrared illumination included in the illumination unit 113 is turned off, and selects illumination center photography when it detects that it is turned on.

Further, the imaging device 100 may have a Day mode and a Night mode, and the signal processing unit 130 may select field angle center imaging in the Day mode, and select illumination center imaging in the Night mode. Here, the Day mode is, for example, a mode for photographing outdoors during the daytime, and may be set when the illuminance of the photographing environment is equal to or higher than a threshold value. Further, the Night mode may be, for example, a mode for photographing outdoors at night, and may be set when the illuminance of the photographing environment is less than a threshold value.

This method is more effective when photographing a distant place. Therefore, for example, if the signal processing unit 130 detects that the zoom magnification of the optical zoom unit 112 has increased, in other words, that the zoom magnification has exceeded a threshold, switching from angle-of-view center photography to illumination center photography is possible. good. In addition, a threshold value is set for the shooting angle, and when shooting at an angle equal to or greater than the threshold value (more than a predetermined angle), switching from angle-of-view centered shooting to illumination centered shooting, and when shooting at an angle less than the threshold value (less than a predetermined angle). You may also perform shooting at the center of the field of view.

Furthermore, by setting a larger threshold value φ for the angle difference 703 between the high-intensity point of the illumination and the center point of the shooting range, resolution is ensured and the illumination range of the lighting is expanded compared to when shooting at the center of the field of view. You can take pictures. Therefore, the threshold value φ may be set in stages. Further, depending on the situation, it may be possible to select the threshold value φ provided in stages.

As described above, in an imaging device that does not individually control the direction of the illumination section 113 and the direction of the imaging section 111, by illuminating the center of the user-specified shooting range so that the center of the illumination hits the center of the shooting range specified by the user, the entire shooting range specified by the user can be illuminated. It becomes possible to take bright pictures. Further, it is possible to suppress the resolution of the photographed image from decreasing unnecessarily, and the visibility of the photographed image is further improved.

(Example 3)
In the embodiment described above, a method was described in which the high brightness point A ₁ of the illumination is aligned with the point of interest B ₁ by repeating the control of the drive unit 120. In the third embodiment, a method of calculating the driving angle γ and aligning the high brightness point A ₁ of the illumination with the point of interest B ₁ will be described. FIG. 8 is a diagram illustrating processing according to the third embodiment. Hereinafter, assuming the imaging apparatus shown in FIG. 8, a method for calculating the imaging angle θ ₂ when switching to illumination center imaging when imaging is performed at the imaging angle θ ₁ will be described. Note that the configuration of the imaging device according to this embodiment is almost the same as that of the first embodiment. However, in this embodiment, the imaging section 111 and the illumination section 113 are arranged at the same distance from the rotation axis.

The intersections of perpendicular lines drawn from point O, point A ₀ , and point B ₀ to the subject plane 202 and the subject plane 202 are defined as point H (reference point), point A ₂ , and point B _{2 ,} respectively. Further, the photographing angle is defined as θ, and is acquired from the photographing angle acquisition unit 140. A line segment A ₀ B ₀ indicates the arrangement distance between the imaging section 111 and the illumination section 113, and is stored in the storage section 340 in advance. The line segment OH indicates the installation height of the imaging device 100, and a value input by the user in advance is stored in the storage unit 340. Note that the method for obtaining the installation height is not limited to user input.

ここで、線分ＨＢ₂（θ）と、線分Ｂ₂Ｂ_１（θ）はそれぞれ既知の値、線分ＯＢ₀、高さＯＨを用いて以下の式（３）で表せる。

次に、水平照射距離ＨＡ₁（θ）は以下の式（４）で表せる。

ここで、線分ＨＡ₂（θ）と、線分Ａ₂Ａ_１（θ）はそれぞれ既知の値、線分ＯＡ₀、高さＯＨを用いて以下の式（５）で表せる。

撮影角度θ₁で撮影していた場合、水平照射距離ＨＡ₁が水平撮像距離ＨＢ₁（θ₁）と同等になる時の角度がθ₂である。したがって、以下の式（６）を計算することでθ₂を算出できる。つまり、演算部３３０は、以下の等式を満たす撮影角度θ₂を算出する。

Below, a method of calculating the imaging angle θ ₂ in illumination center imaging will be explained. The shooting angle θ ₂ is the distance to point B ₁ when point H is the reference (hereinafter, horizontal imaging distance HB ₁ (θ)), and the distance to point A ₁ when point H is the reference (hereinafter referred to as horizontal imaging distance HB 1 (θ)). , horizontal irradiation distance HA ₁ (θ)). The horizontal imaging distance HB ₁ (θ) can be expressed by the following equation (2).

Here, the line segment HB ₂ (θ) and the line segment B ₂ B ₁ (θ) can be expressed by the following equation (3) using known values, the line segment OB ₀ , and the height OH, respectively.

Next, the horizontal irradiation distance HA ₁ (θ) can be expressed by the following equation (4).

Here, the line segment HA ₂ (θ) and the line segment A ₂ A ₁ (θ) can be expressed by the following equation (5) using known values, the line segment OA ₀ , and the height OH, respectively.

When photographing is performed at the photographing angle θ ₁ , the angle at which the horizontal irradiation distance HA ₁ becomes equal to the horizontal imaging distance HB ₁ (θ ₁ ) is θ ₂ . Therefore, θ ₂ can be calculated by calculating the following equation (6). That is, the calculation unit 330 calculates the photographing angle θ ₂ that satisfies the following equation.

FIG. 9 is a flowchart showing processing according to the third embodiment. Each operation (step) shown in this flowchart can be executed by the signal processing unit 130. Since S601 to S603 in FIG. 9 are almost the same as those in FIG. 6, their explanation will be omitted here.

(S904) The calculation unit 330 reads the installation height OH input by the user in S901 from the storage unit 340, and proceeds to S905.
(S905) The calculation unit 330 reads the arrangement distance between the imaging unit 111 and the illumination unit 113, which has been stored in advance in the storage unit 340, and proceeds to S906.
(S906) The calculation unit 330 uses the read value to calculate and obtain the imaging angle θ ₂ for illumination center imaging, and the process proceeds to S907.

(S907) The drive control unit 313 controls the drive unit 120 to rotate the imaging illumination unit 110 so that the imaging angle is θ ₂ , and the process proceeds to S908.
(S908) The imaging control unit 321 controls the optical zoom unit 112 to change the imaging angle of view from the angle of view β ₁ to the angle of view β ₂ (=β ₁ +2×(θ ₂ - θ ₁ )), and starts the process. finish.
According to this embodiment, the processing time when performing illumination center photography can be further reduced.

Here, a method for calculating the photographing angle θ ₂ in illumination center photography has been described. The value of the photographing angle θ ₂ in illumination center photography for each photographing angle θ is stored in advance in the storage unit 340, and the photographing angle θ ₁ You may also read and obtain the value according to the . In this case, the drive control section 313 controls the drive section 120 according to the obtained result. By doing so, it becomes possible to further shorten the processing time.

(Other examples)
Although the present invention has been described above in detail based on its preferred embodiments, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the gist of the present invention. It is not excluded from the scope of the invention.

Further, a computer program that implements some or all of the functions of the above-described embodiments of control in this embodiment may be supplied to the imaging device via a network or various storage media. Then, the computer (or CPU, MPU, etc.) in the imaging device may read and execute the program. In that case, the program and the storage medium storing the program constitute the present invention.

100 Imaging device 110 Imaging illumination section 111 Imaging section 112 Optical zoom section (angle of view changing section)
113 Illumination unit 120 Drive unit 130 Signal processing unit 140 Shooting angle acquisition unit 150 User interface 160 Network 170 Client device

Claims (15)

an imaging unit;
an illumination unit arranged so that its optical axis is different from that of the imaging unit;
a driving unit that can integrally drive the imaging unit and the illumination unit;
a view angle changing unit capable of changing the shooting view angle of the imaging unit ;
comprising a control unit that controls the angle of view changing unit and the drive unit,
The control unit is configured to control, when the lighting unit is turned on, a captured image of a center point of a specified shooting range and a high brightness point having a luminance of a predetermined value or more in the range illuminated by the lighting unit. The drive unit is driven so that the distance at the top is less than a threshold, the view angle changing unit is controlled to widen the photographing angle of view according to the amount by which the drive unit is driven, and the drive unit is driven. An image capturing apparatus is characterized in that an image of the designated photographing range is cut out from a photographed image photographed with a photographing angle of view widened according to an amount of the image. The control unit drives the drive unit at a predetermined angle, and repeats control of the drive unit and the view angle changing unit until the distance between the center point and the high brightness point becomes less than a threshold. The imaging device according to claim 1, characterized in that : comprising a photographing angle acquisition unit that acquires a photographing angle of the imaging device;
The control unit may determine the amount by which the driving unit is driven based on the photographing angle and the distance between the center point and the high brightness point when photographing the specified photographing range. The imaging device according to claim 1 or 2. The control unit obtains an amount to drive the driving unit using the arrangement distance between the imaging unit and the illumination unit, the installation height of the imaging device, and the shooting angle of the imaging device, and applies the information to the obtained result. The imaging device according to claim 1, wherein the driving section is driven accordingly. The control unit determines a photographing angle in the specified photographing range as θ1, a photographing angle at which the distance is less than a threshold value as θ2, and a distance from a reference point to an intersection of an optical axis of the illumination unit and a subject plane. The method is characterized in that the amount by which the driving unit is driven is calculated so as to satisfy the following equation, where HA1 is a distance from the reference point to the intersection of the optical axis of the imaging unit and the object surface as HB1. The imaging device according to claim 4.

The imaging device according to claim 4 or 5, further comprising a storage unit that stores in advance an arrangement distance between the imaging unit and the illumination unit. The imaging device according to any one of claims 1 to 6, wherein the control unit acquires brightness information of the photographed image and sets the brightest point in the photographed image as the high brightness point. . The imaging device according to any one of claims 1 to 7, wherein a user specifies the imaging range. 9. The control section does not change the light distribution angle of the illumination section when widening the angle of view according to the amount by which the drive section is driven. The imaging device described in . 10. The control unit is capable of selecting whether or not to control the distance between the center point and the high brightness point on the captured image to be less than a threshold value. The imaging device according to any one of the items. The control unit controls the drive unit so that the distance between the center point and the high brightness point on the captured image is less than a threshold when it is detected that the illumination unit is turned on; When it is detected that the illumination unit is turned off, the drive unit is not controlled so that the distance between the center point and the high brightness point on the photographed image is less than a threshold value, and the center point The imaging device according to any one of claims 1 to 10, wherein the imaging device performs imaging in the specified imaging range centered on . When the control unit detects that the image is being photographed at a photographing angle equal to or greater than a predetermined angle, the control unit controls the drive unit so that the distance between the center point and the high-intensity point on the photographed image becomes less than a threshold value. the drive such that when it is detected that the photographing angle is less than the predetermined angle, the distance between the center point and the high brightness point on the photographed image becomes less than a threshold value; The imaging device according to any one of claims 1 to 11, characterized in that the imaging device performs imaging in the specified imaging range centered on the center point without controlling the area. an imaging unit; an illumination unit disposed such that its optical axis is different from that of the imaging unit; a drive unit capable of driving the imaging unit and the illumination unit together ; and a view angle changing unit capable of changing a photographing angle of view. A method for controlling an imaging device, comprising:
When the illumination unit is turned on, the distance on the photographed image between the center point of the designated photographing range and a high brightness point having a luminance equal to or higher than a predetermined value in the range illuminated by the illumination unit is a threshold value. the drive unit and the illumination unit are integrally driven so that the angle of view is less than or equal to the angle of view; A control method characterized in that an image of the specified photographing range is cut out from a photographed image photographed with a photographing angle of view widened according to the amount of the adjustment. A program for causing a computer to execute the method for controlling an imaging device according to claim 13. A computer readable storage medium storing the program according to claim 14.

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