JP7615835B2 - Camera control device and camera - Google Patents

Description

The present invention relates to a camera control device and a camera.

Camera that adjusts focus based on the defocus amount is known (see Patent Document 1). There has been a demand for improving the accuracy of focus adjustment.

JP 2014-206601 A

A camera control device according to a first aspect of the present invention comprises a determination unit that determines whether or not structural information is included in an image of the subject light based on a signal from an imaging unit that receives subject light that has passed through an optical system using a plurality of photoelectric conversion units, photoelectrically converts the subject light, and outputs a plurality of photoelectrically converted signals; a movement possibility setting unit that sets a focus lens of the optical system to be movable if the determination unit determines that the structural information is included, and sets the focus lens of the optical system to be movable or not if the determination unit determines that the structural information is not included ; and a detection unit that detects by calculation an amount of defocus, which is the amount of deviation between the focus of the optical system and the position of the imaging unit, based on the phase difference between a set of images formed by light beams that have passed through different pupils of the optical system.If the detection unit is unable to detect the amount of defocus and the movement possibility setting unit has set the focus lens to be movable, a signal to move the focus lens a predetermined amount is sent to the optical system, and after the focus lens has moved in accordance with the signal, the detection unit re-executes calculation to detect the amount of defocus .
A camera according to a second aspect of the present invention includes the camera control device according to the first aspect and the imaging section .

1 is a schematic diagram illustrating a configuration of a main part of a camera system according to a first embodiment. 11 is a flowchart illustrating the flow of a process executed by a camera control unit. FIG. 2 is a diagram illustrating an example of a shooting range. FIG. 4(a) is a schematic diagram showing a histogram generated using imaging pixel signals corresponding to focus point P1, and FIG. 4(b) is a schematic diagram showing a histogram generated using imaging pixel signals corresponding to focus point P2. FIG. 5A is a schematic diagram illustrating a difference in frequency distribution depending on the number of classes (class width), and FIG. 5B is a schematic diagram illustrating a difference in frequency distribution depending on the shift amount. 11 is a flowchart illustrating a process for setting whether or not the focus lens can be moved. 13 is a flowchart illustrating the flow of a structure determination process using a histogram. 10 is a flowchart illustrating a process for setting whether or not the focus lens can be moved according to a second embodiment.

Hereinafter, an embodiment of the invention will be described with reference to the drawings.
A camera system 1 according to one embodiment of the present invention has an autofocus (AF) adjustment function, and when the defocus amount is large and the image of the subject is significantly blurred, it determines whether the subject is one for which focus can be adjusted, and decides whether or not to perform a scanning movement of the focus lens based on the determination result.
In the following description, an overview of the camera system 1 will be given first, and then the process of determining whether or not the subject is a focus adjustable subject will be described.

(First embodiment)
1 is a schematic diagram illustrating the configuration of the main parts of a camera system 1 according to a first embodiment. The camera system 1 will be described as an example in which a detachable photographing lens (referred to as an interchangeable lens 3) is attached to a camera body 2, but the camera may also be one in which the camera body 2 and the photographing lens are integrated.
In FIG. 1, the horizontal direction in a plane intersecting with the optical axis O of the interchangeable lens 3 is defined as the X-axis, and the vertical direction is defined as the Y-axis.

<Camera body>
The camera body 2 has a camera control unit 230, a body communication unit 240, an image sensor 260, a signal processing unit 270, an operation member 280, and a display unit 290. The camera control unit 230 is connected to the body communication unit 240, the image sensor 260, the signal processing unit 270, the operation member 280, and the display unit 290.

The camera control unit 230 is composed of a microcomputer and its peripheral circuits. The camera control unit 230 includes a memory unit 235 that stores the control program executed by the camera control unit 230, a focus detection unit 230a that controls the focus detection calculation by the AF signal processing unit 270b, a movement permission setting unit 230b that sets whether or not the scan movement of the focus lens 361 described later is possible, a condition setting unit 230c that sets the generation conditions of a histogram described later, a generation unit 230d that generates a histogram, and a structure determination unit 230e that determines whether or not structural information is included in the image of the subject based on the histogram. The structural information will be described later. The camera control unit 230 executes the control program stored in the memory unit 235 to control each unit in the camera body 2. The recording and reading of data in the memory unit 235 is controlled by the camera control unit 230.

The body communication unit 240 performs predetermined communication with the lens communication unit 340 of the interchangeable lens 3. The body communication unit 240 is connected to the camera control unit 230.

Light from the subject that passes through the interchangeable lens 3 is guided to the imaging surface 260S of the imaging element 260. The imaging element 260 is a solid-state imaging element such as a CMOS image sensor or a CCD image sensor. The imaging element 260 captures an image of the subject formed on the imaging surface 260S in response to a control signal from the camera control unit 230, and outputs a signal corresponding to the luminance distribution of the image of the subject. The camera system 1 is capable of capturing video and still images. In addition to recording video, video capture also includes capturing so-called through images (also called live view images) for continuously displaying images for monitoring on the display unit 290.

The image sensor 260 has a photoelectric conversion unit for image generation and a photoelectric conversion unit for focus detection. An image pixel signal based on the charge generated by the photoelectric conversion unit for image generation is used to generate image data by an image signal processing unit 270a of the signal processing unit 270. A focus detection pixel signal based on the charge generated by the photoelectric conversion unit for focus detection is used by an AF signal processing unit 270b of the signal processing unit 270 for focus detection calculation (also called AF calculation) that detects the focus state of the subject image formed by the photographing optical system 360, in other words, the deviation between the position of the subject image in the optical axis O direction and the position of the imaging surface 260S of the image sensor 260.
The imaging element 260 is connected to the signal processing unit 270 and the camera control unit 230 .

The signal processing unit 270 includes an image signal processing unit 270a and an AF signal processing unit 270b. The image signal processing unit 270a performs a predetermined image processing on the imaging pixel signals output from the imaging element 260 to generate image data. The generated image data is recorded in a predetermined file format on a storage medium (such as a memory card) (not shown), or is used to display a live view image before shooting or a confirmation image after shooting.

In addition, the AF signal processing unit 270b calculates a defocus amount by performing focus detection calculation using a phase difference detection method using focus detection pixel signals output from the image sensor 260. The defocus amount is the amount of deviation between the position of the subject image formed by the photographing optical system 360 and the image pickup surface 260S.
The signal processing unit 270 is connected to the camera control unit 230 , the image pickup element 260 , and the display unit 290 .

Operation members 280, including a release button and operation switches, are provided on the exterior surface of the camera body 2. The operation members 280 send operation signals to the camera control unit 230 in response to user operations. The user issues shooting instructions and shooting condition setting instructions by operating the operation members 280. The user can also use the operation members 280 to instruct switching of the "AF area mode" described below.

The display unit 290 is configured with an organic EL display panel or a liquid crystal display panel. The display unit 290 displays an image based on image data processed by the image signal processing unit 270a, an operation menu screen, and the like, in response to a control signal from the camera control unit 230. The display unit 290 may also be provided with a touch panel to configure a touch operation member 290A as a part of the operation member 280.
The display unit 290 is connected to the camera control unit 230 .

<Interchangeable lenses>
The interchangeable lens 3 has a lens control unit 330, a lens communication unit 340, a photographing optical system 360, a lens driving unit 370, and an aperture driving unit 380. The lens control unit 330 is connected to the lens communication unit 340, the lens driving unit 370, and the aperture driving unit 380.

The lens control unit 330 is composed of a microcomputer and its peripheral circuits. The lens control unit 330 executes a control program stored therein and controls each part of the interchangeable lens 3, such as controlling the movement of the focus lens 361 during AF operation.

The lens communication unit 340 performs a predetermined communication with the body communication unit 240. Instructions to move the focus lens 361 and the like are sent from the camera body 2 to the interchangeable lens 3 through communication between the lens communication unit 340 and the body communication unit 240. In addition, information such as the drive state of the focus lens 361 is sent from the interchangeable lens 3 to the camera body 2 through communication between the lens communication unit 340 and the body communication unit 240.

The photographing optical system 360 includes multiple lenses and an aperture member 362, and directs subject light to the imaging surface 260S of the image sensor 260 in the camera body 2. Of the multiple lenses, the focus lens 361 is configured to be movable in the direction of the optical axis O by a lens drive unit 370. As the focus lens 361 moves, the position of the subject image formed by the photographing optical system 360 moves in the direction of the optical axis O. This allows the lens to be driven (focus drive) for focusing.

The aperture 362 adjusts the amount of light incident on the image sensor 260. The aperture 362 is configured so that the aperture blades can be driven by the aperture drive unit 380 or manually to change the aperture diameter (aperture value).

Drive instructions such as the direction, amount, and speed of movement of the focus lens 361 are issued by the camera control unit 230. Note that the lens control unit 330 may issue drive instructions such as the direction, amount, and speed of movement of the focus lens 361 based on information from the camera control unit 230.

<Example of camera operation>
An example of the camera operation of the above-described camera system 1 will be described.
Fig. 2 is a flowchart illustrating the flow of processing executed by the camera control unit 230. The camera control unit 230 starts the processing according to the flowchart in Fig. 2, for example, at the time of startup following the turning on of a main switch.

In step S10, the camera control unit 230 sets the exposure for the live view image, performs accumulation control (exposure control) on the image sensor 260, and proceeds to step S15. The exposure setting value for the first image captured after startup is controlled to a predetermined initial value, and accumulation control is performed on the image sensor 260.

In step S15, the camera control unit 230 causes the signal processing unit 270 to read out the signal from the image sensor 260, and proceeds to step S20. The camera control unit 230 calculates each control value by performing exposure calculation in step S20. That is, the camera control unit 230 detects brightness information (Bv value) of the subject based on the image pixel signal input to the signal processing unit 270, and determines the aperture value (Av value), shutter speed (Tv value), and sensitivity (Sv value) based on the Bv value and the program diagram information stored in the memory unit 235, and proceeds to step S25. Each calculated control value is stored in the memory unit 235.

In step S25, the camera control unit 230 controls the aperture drive unit 380 via the lens control unit 330 to set the aperture 362 to the determined aperture value. The camera control unit 230 causes the image signal processing unit 270a to generate a live view image using the imaging pixel signals output from the imaging element 260, and causes the display unit 290 to display the generated live view image.

In step S30, the focus detection unit 230a of the camera control unit 230 causes the AF signal processing unit 270b to perform AF calculations, and the process proceeds to step S40. The AF calculations calculate the defocus amount based on the focus detection pixel signals output from the image sensor 260.

The movement permission setting unit 230b of the camera control unit 230 determines in step S40 after the AF calculation (step S30) whether or not the focus lens 361 can be moved. This determination process is performed to avoid unnecessary scanning operation of the focus lens 361 when the defocus amount cannot be calculated by the AF calculation.
Conventionally, the scanning operation of the focus lens 361 is performed when the AF signal processing unit 270b cannot calculate the defocus amount, and the focus lens 361 is moved by a predetermined movement amount in the direction of the optical axis O to increase the possibility of calculating the defocus amount. In other words, the focus lens 361 is scanned in order to improve the blur state of the subject image from a state in which the subject image is so blurred that the contour, pattern, etc. of the subject image disappears to such an extent that the defocus amount cannot be calculated, so that the contour, pattern, etc. of the subject image appear to such an extent that the defocus amount can be calculated. Note that the scanning operation may involve moving the focus lens 361 over the entire range from close to infinity.

If the defocus amount cannot be calculated even if the focus lens 361 is scanned, the scan operation is wasted. Therefore, in the embodiment, the lens movement of the scan operation is not performed for a subject for which the blur of the image of the subject is not improved even if the lens movement is performed. For example, the contour or pattern of the subject image required for AF calculation may not appear because the contour or pattern of the subject is not clear to begin with, or the contour or pattern of the subject image required for AF calculation may be insufficient because the contour or pattern of the subject is not clear to begin with, making it impossible to calculate the defocus amount. In such a case, even if the lens movement of the scan operation is performed, it is unlikely that the defocus amount will be calculated. Therefore, in the present embodiment, if the movement possibility setting unit 230b does not set the lens movement possibility of the scan operation, the lens movement of the scan operation is not performed. Details will be described later.

In addition, if the defocus amount can be calculated by the AF calculation (S30), the movement feasibility setting unit 230b sets the lens movement of the focus lens 361 based on the defocus amount, i.e., sets the lens movement of the focus adjustment operation, and drives the focus lens 361 to focus in the direction of the optical axis O (step S50).
There are two cases where the lens movement possible is set in step S40: when the defocus amount has been calculated, and when the defocus amount has not been calculated but the subject image contains structural information. The former movement possible setting causes a lens movement operation to be performed as a focus adjustment operation, and the latter movement possible setting causes a scan operation for AF recalculation. In this specification, the former is called lens movement possible for focus adjustment operation, and the latter is called lens movement possible for scan operation. The structural information will be described later.
The setting results of step S40 are stored as three types of flags: lens movement possible for focus adjustment operation, lens movement possible for scanning operation, and lens movement not possible for scanning operation, and are used in the lens drive control process described later.
The process of setting whether or not the focus lens 361 can be moved (S40) will be described in detail below with reference to FIGS.

After the setting process of step S40, the camera control unit 230 proceeds to step S45. In step S45, the camera control unit 230 determines whether or not the release button has been half-pressed. If the release button has not been half-pressed, the camera control unit 230 makes a negative judgment in step S45 and returns to step S10. In contrast, if the release button has been half-pressed, the camera control unit 230 makes a positive judgment in step S45 and proceeds to step S48. In step S48, the camera control unit 230 determines whether or not the lens can be moved, and if the flag indicating that the lens can be moved for the focus adjustment operation is set, the camera control unit 230 proceeds to step S50, and if the flag indicating that the lens can be moved for the focus adjustment operation is not set, the camera control unit 230 proceeds to step S52.

In step S50, which is proceeded to when the focus adjustment operation is performed and the lens is movable, the camera control unit 230 causes a drive signal corresponding to the drive amount of the focus lens 361 calculated in step S30 to be transmitted from the body communication unit 240 to the interchangeable lens 3. As a result, the lens control unit 330 issues an instruction to the lens drive unit 370 to drive the focus lens 361, which is an instruction to drive the focus lens 361.
The camera control unit 230 further performs an operation to inform the user that the focus drive has been performed. The camera control unit 230 causes a display (AF frame) indicating the adopted focus point P to be lit for a predetermined period of time, for example. After that, the camera control unit 230 proceeds to step S60.

Furthermore, if the flag indicating that the lens can be moved for the focus adjustment operation is not set, a negative judgment is made in step S48, and the process proceeds to step S52. In step S52, it is judged whether a flag indicating that the lens can be moved or not for the scan operation is set. If the flag indicating that the lens can be moved for the scan operation is set, the camera control unit 230 proceeds to step S54. In step S54, the camera control unit 230 causes the body communication unit 240 to transmit an instruction to move the focus lens 361 in the direction of the optical axis O for the scan operation to the interchangeable lens 3. This is an instruction for scan drive. Furthermore, the camera control unit 230 returns to step S30 to execute AF calculation in the same manner as described above, and then proceeds to step S40.
On the other hand, if the flag indicating that the lens is not to be moved in the scan operation is set in step S52, the process proceeds to step S58. In step S58, the camera control unit 230 performs a display process including an operation of informing the user that focus driving cannot be performed. As the display process, the camera control unit 230 causes a display (AF frame) indicating the focus point P being used to blink for a predetermined period of time, for example. Thereafter, the camera control unit 230 proceeds to step S60. In this way, if the flag indicating that the lens is not to be moved in the scan operation is set, the camera control unit 230 does not send a drive instruction for the focus lens 361 to the interchangeable lens 3, so that unnecessary driving of the focus lens 361 can be avoided.

In step S60, the camera control unit 230 determines whether the release button has been fully pressed. If the release button has been fully pressed, the camera control unit 230 makes a positive judgment in step S60 and proceeds to step S65, and if the release button has not been fully pressed, the camera control unit 230 makes a negative judgment in step S60 and returns to step S10.

After returning to step S10, the camera control unit 230 again performs the processes from step S10 onwards. The exposure settings for the second and subsequent frames of the live view image use the aperture value stored in the memory unit 235, and the shutter speed (Tv value) and sensitivity (Sv value) stored in the memory unit 235.

In step S65, which is reached when the release button is fully pressed (a positive judgment in step S60), the camera control unit 230 causes the image sensor 260 to perform a storage operation for capturing an image for recording. At that time, the aperture 362 is set to the aperture value (Av value) stored in the storage unit 235, storage control of the image sensor 260 is performed at the shutter speed (Tv value) stored in the storage unit 235, and processing is performed using the sensitivity (Sv value) stored in the storage unit 235.

In step S70, the camera control unit 230 reads out the signal from the imaging element 260 to the signal processing unit 270, and proceeds to step S75. In step S75, the camera control unit 230 causes the image signal processing unit 270a to perform a predetermined image processing on the imaging pixel signal output from the imaging element 260, and generate an image for recording. As a result, the image signal processing unit 270a performs the predetermined image processing to generate an image for recording.

In step S80, the camera control unit 230 performs image display. That is, the camera control unit 230 causes the display unit 290 to display the image processed in step S75 as a confirmation image.
In step S85, the camera control unit 230 causes the file of the image processed by the image signal processing unit 270a to be recorded in a recording unit (not shown).

In step S90, the camera control unit 230 determines whether or not to end the series of processes. For example, if the main switch is turned off, the camera control unit 230 makes a positive judgment in step S90 and ends the process in FIG. 2. If the camera control unit 230 does not want to end the process in FIG. 2 and wants to continue the camera operation, it makes a negative judgment in step S90 and returns to step S10.

The display process (S80) and the recording process (S85) may be performed in a different order, or may be performed in parallel.
Also, in the example of Figure 2, the defocus amount is calculated in the AF calculation (S30) after the live view display (S25) is performed, but the AF calculation (S30) and lens movement enable/disable setting (S40) may be performed in parallel with the exposure calculation (S20), and after a half-press operation is performed in step S45, an instruction to drive the focus lens 361 may be given to the interchangeable lens 3 (S50).
Furthermore, each time a frame of a live view image is captured, AF calculation (S30), lens movement enable/disable setting (S40), and drive instructions for the focus lens 361 (S50) may be performed in parallel with the exposure calculation (S20).

<Focus point>
The focus points used in the AF calculation (S30) will be described.
Fig. 3 is a diagram illustrating an example of a shooting range 50 imaged by the image sensor 260 of the camera body 2. In this embodiment, a plurality of (e.g., 135) focus points P are provided in advance in the shooting range 50, and in Fig. 3, the 135 focus points P are displayed superimposed on a live view image displayed on the display unit 290. The focus points P indicate positions in the shooting range 50 that are subject to AF calculation, and are also referred to as focus detection areas, focus detection positions, or distance measurement points.
It should be noted that the number of focus points P and their positions in the photographing range 50 shown in the figure are merely an example, and are not limited to the embodiment shown in FIG.

The focus point P that the AF signal processor 270b uses to calculate the defocus amount, in other words, the focus point P that is the subject of the AF calculation, can be automatically selected from among all focus points P, or can be selected from a focus point P designated by a user operation. In this embodiment, the selection method for selecting the focus point P to be used to calculate the defocus amount from among all focus points P is collectively referred to as the "AF area mode."

The "AF area modes" include "single-point AF", which uses only one focus point P selected by user operation, "wide-area AF", which uses multiple focus points P in a wider range than single-point AF, and "auto-area AF", in which the camera control unit 230 detects a subject from the range in which all focus points P are located and uses the focus point P located within the range of that subject. The "AF area mode" can be switched by the user's operation, for example, from the operation menu screen.

<AF Calculation>
The AF calculation (S30) can be generally described as follows. The AF signal processing unit 270b calculates, by AF calculation, a defocus amount, which is the amount of deviation in the optical axis O direction between the position of the subject image formed by the light beam that has passed through the interchangeable lens 3 and the position of the imaging surface 260S of the image sensor 260 of the camera body 2, based on a focus detection pixel signal from a focus detection photoelectric conversion unit. The focus detection pixel signal used by the AF signal processing unit 270b for the AF calculation is a focus detection pixel signal output from a focus detection photoelectric conversion unit that is arranged on the imaging surface 260S of the image sensor 260 at a position corresponding to the focus point (e.g., P1) that is adopted in accordance with the switching of the above-mentioned "AF area mode."

The AF signal processing unit 270b can detect the amount of image shift (phase difference) of the subject image caused by a pair of light beams that have passed through different regions (pupils) of the interchangeable lens 3 for each focus point P, and can calculate the amount of defocus for each focus point P. Such defocus amount calculation using the pupil division phase difference method is well known in the field of cameras.
The focus detection unit 230a calculates the amount of drive of the focus lens 361 in the optical axis O direction based on the defocus amount calculated by the AF signal processing unit 270b.

In this embodiment, the interchangeable lens 3 drives the focus lens 361 to focus when the release button is pressed halfway. Specifically, when the release button is pressed halfway, the camera control unit 230 causes the body communication unit 240 to transmit a drive signal for the focus lens 361 corresponding to the drive amount calculated by the focus detection unit 230a to the interchangeable lens 3. The interchangeable lens 3 moves the focus lens 361 in accordance with the drive signal transmitted from the body communication unit 240, thereby performing focus drive so that the position of the image of the subject present in the area corresponding to the focus point P1 is aligned with the position of the imaging surface 260S of the image sensor 260.

The camera control unit 230 can visually inform the user that focus driving has been performed. Specifically, when the camera control unit 230 transmits a drive signal for the focus lens 361 to the interchangeable lens 3, it causes a display (called an AF frame) indicating the focus point P1 being used to be displayed and lit for a predetermined period of time, superimposed on the live view image displayed on the display unit 290. The example in FIG. 3 shows a state in which the AF frame indicating the focus point P1 is displayed on the display unit 290.

<Lens movement setting>
The lens movement enable/disable setting (S40) performed in the series of camera operations described above will be described with reference to Figures 4 to 7. Figures 4(a) and 4(b) are schematic diagrams illustrating histograms used in the lens movement enable/disable setting (S40), where Figure 4(a) is a histogram generated using imaging pixel signals corresponding to focus point P1 in Figure 3, and Figure 4(b) is a histogram generated using imaging pixel signals corresponding to focus point P2 in Figure 3.
The generation section 230d generates a histogram using the imaging pixel signals corresponding to the adopted focus point P, among the imaging pixel signals output from the image sensor 260, in the following procedure.

Step (1)
The generation unit 230d acquires imaging pixel signals corresponding to the adopted focus point P. When the signal value is represented in 8 bits, the signal value of the imaging pixel signal is represented by 0 to 255. The number of imaging pixel signals corresponding to the focus point P increases as the range of the focus point P increases, and decreases as the range of the focus point P decreases.

Step (2)
The generation section 230d divides the acquired imaging pixel signals into a plurality of classes based on the histogram generation conditions set by the condition setting section 230c. For example, when the signal values of the imaging pixel signals range from 0 to 255 and the class width is set to 18 by the condition setting section 230c, the number of classes is 14. The condition setting section 230c can change the number of classes (class width) as appropriate.

Step (3)
The generation unit 230d generates a histogram showing the frequency distribution, with the number of imaging pixel signals included in each class being the frequency. Note that Figures 4(a) and 4(b) are shown as examples for the purpose of explanation, and it is sufficient if data necessary for generating the histogram is generated, even if the histograms shown in Figures 4(a) and 4(b) are not actually generated.

<Histogram shape and presence or absence of structural information in the subject image>
In this embodiment, when the subject image contains predetermined structural information indicated by contours, patterns, etc. indicating the structure of the subject (also simply referred to as structure), and when information necessary for AF calculation is obtained, and in this embodiment, the defocus amount is calculated, it is said that the subject image has structural information. Conversely, when the subject's contours, patterns, etc. are not present and information necessary for AF calculation is not obtained or is insufficient, and in this embodiment, the defocus amount is not calculated, it is said that the subject image does not have structural information.

In general, when the defocus amount is large (the image is significantly out of focus), that is, when the image of the subject is significantly blurred, it becomes difficult to determine whether or not the image of the subject has structural information. In this embodiment, when it is difficult to determine whether or not the image of the subject has structural information, the presence or absence of structural information in the image of the subject is determined based on a histogram generated from the imaging pixel signals.
The determination of the presence or absence of structural information in the subject image, which is made based on the histogram, is based on the following two concepts.
(i) When there is no structural information in the subject image, the signal values are concentrated in approximately one class of the histogram (the histogram shape has approximately one peak), as shown in the example of FIG. 4(b).
(ii) When the defocus amount is large and the subject image contains structural information, the signal values are divided into multiple classes in the histogram, and the shape of the histogram becomes broad (spread across multiple classes), as shown in FIG. 4( a).

<Determining the presence or absence of structural information in the image of the subject>
The structure determination section 230e determines the presence or absence of structural information of the subject image based on the histogram generated by the generation section 230d, depending on whether or not the following two determination conditions are satisfied.
Judgment condition (1)
The judgment condition (1) is to judge whether the ratio of the first peak to the second peak in the histogram is greater than a first threshold value (e.g., 10 times) and whether the first peak is remarkably greater, in other words, whether it is far superior. The first peak refers to the frequency of the class with the highest frequency, and the second peak refers to the frequency of the class with the second highest frequency.

Judgment condition (2)
The judgment condition (2) is that the ratio of the sum of the frequencies of the classes below the second peak, excluding the class of the first peak, in the histogram to the total frequency is smaller than a second threshold (e.g., 10%). In other words, it is judged whether the frequency of the class of the first peak exceeds 90% of the total.
The structure determination unit 230e determines that the subject image does not have structural information if the determination conditions (1) and (2) are simultaneously satisfied, and determines that the subject image has structural information if either the determination condition (1) or the determination condition (2) is not satisfied.

<Make multiple judgments>
In this embodiment, in order to avoid erroneous determination of the presence or absence of structural information of the subject image, the structure determination unit 230e determines the presence or absence of structural information of the subject image multiple times based on multiple histograms generated under different setting conditions. If the result of multiple determinations by the structure determination unit 230e is that there is no structural information of the subject image, the movement permission setting unit 230b determines that the structure determination unit 230e has determined that "there is no structural information of the subject image."
On the other hand, if the structure determination unit 230e determines whether or not there is structural information on the subject image multiple times and determines that there is structural information on the subject image at least once, the movement feasibility setting unit 230b determines that the structure determination unit 230e has determined that "structural information on the subject image is present."

<Conditions for generating a histogram>
The condition setting unit 230c can set the following three conditions as conditions for generating a histogram.
Setting condition (1)
The condition setting unit 230c sets the colors used to generate the histogram. In general, the photoelectric conversion unit of the image sensor 260 is provided with a color filter. The color filter is any one of a color filter having a spectral characteristic of separating light in a first wavelength range (red (R)) of the incident light, a color filter having a spectral characteristic of separating light in a second wavelength range (green (G)) of the incident light, and a color filter having a spectral characteristic of separating light in a third wavelength range (blue (B)) of the incident light.
The generation unit 230d generates a histogram using imaging pixel signals corresponding to the focus point P being adopted, which are based on charges generated by a photoelectric conversion unit provided with a color filter of the color set by the condition setting unit 230c, for example, green (G).

Setting condition (2)
The condition setting unit 230c sets the number of classes (class width) for generating a histogram. Fig. 5(a) is a schematic diagram illustrating the difference in frequency distribution depending on the number of classes (class width). As shown in Fig. 5(a), the class width is narrower in the upper section than in the lower section. In general, if there are too many classes (the class width is too narrow), the peaks of the histogram are scattered and the characteristics of the histogram are difficult to see. Conversely, if there are too few classes, the peaks of the histogram are difficult to see.
The condition setting unit 230c sets the width of the classes so that the number of classes is approximately 10 to 15, for example.

Setting condition (3)
The condition setting unit 230c sets the shift amount of the class boundary. Shifting refers to shifting the class boundary without changing the class width. Fig. 5(b) is a schematic diagram illustrating the difference in frequency distribution depending on the shift amount. According to Fig. 5(b), the class boundary in the upper section is shifted by half the class width compared to the lower section. In other words, the shift amount is 1/2 the class width. The shift amount of the class boundary is also called the phase of the class boundary.

<Explanation of the Flowchart>
FIG. 6 is a flowchart illustrating the flow of the process (S40) for setting whether or not the focus lens 361 can be moved.
The camera control unit 230 starts the process according to the flowchart of FIG. 6 as step S40 of FIG.

In step S410, the movement permission setting unit 230b of the camera control unit 230 judges whether the defocus amount at the adopted focus point P has been calculated. In general, when the contour or pattern of the image of the subject appears, the AF signal processing unit 270b can detect the image shift amount (phase difference) of the image of the subject, and the defocus amount can be calculated based on the detected phase difference. Therefore, if the AF signal processing unit 270b has calculated the defocus amount, the movement permission setting unit 230b judges step S410 as positive and proceeds to step S540. If the process proceeds to step S540, it is not necessary to judge whether or not there is structural information of the image of the subject because the defocus amount has been calculated. In step S540, the movement permission setting unit 230b sets a flag indicating that the focus lens 361 can be moved based on the defocus amount, and ends the process in FIG. 6. As described above, this flag indicates whether the lens can be moved in the focus adjustment operation.

On the other hand, if the AF signal processing unit 270b has not calculated the defocus amount, the movement permission setting unit 230b makes a negative judgment in step S410 and proceeds to step S420. If the process proceeds to step S420, either the image of the subject is so blurred that the defocus amount cannot be calculated despite the subject having structural information, or the subject does not have structural information, so the process from step S420 onwards is carried out to distinguish between the two cases.

In step S420, the condition setting unit 230c of the camera control unit 230 sets the colors to be used in generating the histogram as the above-mentioned setting condition (1). The condition setting unit 230c predetermines, for example, that the color to be set the first time is green, the color to be set the second time is blue, and the color to be set the third time is red. In this embodiment, the determination of the presence or absence of structural information of the subject image multiple times based on multiple histograms generated with different colors is referred to as a "color scan."

In step S430, the condition setting unit 230c of the camera control unit 230 sets the class to be used in generating the histogram as the above-mentioned setting condition (2). The condition setting unit 230c predetermines, for example, the class to be set the first time, the class to be set the second time, and the class to be set the third time. In this embodiment, the determination of the presence or absence of structural information of the subject image multiple times based on multiple histograms generated with different classes is referred to as a "class scan."

In step S440, the condition setting unit 230c of the camera control unit 230 sets the phase of the class boundary used to generate the histogram as the above-mentioned setting condition (3). The condition setting unit 230c predetermines, for example, that the phase (amount of shift) to be set the first time is zero, and the phase (amount of shift) to be set the second time is 1/2 the class width. As a result, the class boundary is not shifted in the first setting, and the class boundary is shifted by 1/2 the class width compared to the first setting in the second setting.
In this embodiment, the determination of the presence or absence of structural information of the subject image based on a plurality of histograms generated with different phases is referred to as a "phase scan."
The images used to detect the presence or absence of structural information in the "color scan,""classscan," and "phase scan" are the same images used in the AF calculation in step S410.

In step S450, the structure determination unit 230e of the camera control unit 230 performs a determination process based on the histogram generated by the generation unit 230d. As described above, the structure determination process in step S450 is performed multiple times for multiple histograms generated under different setting conditions. The determination result in step S450 is either that the subject image has structural information or that the subject image does not have structural information. In the former case, the structure presence/absence flag is set to 1, and in the latter case, the structure presence/absence flag is set to zero (0).
The details of step S450 will be described later with reference to FIG.

In step S460, the movement permission setting unit 230b of the camera control unit 230 determines whether the structure determination unit 230e has determined that there is structural information on the subject image, i.e., whether the structure presence/absence flag is 1. If the structure determination process (S450) using the most recent histogram has determined that there is structural information on the subject image and the flag is set to 1, the movement permission setting unit 230b makes a positive judgment in step S460 and proceeds to step S470. The movement permission setting unit 230b then sets a flag indicating that the lens can be moved for the scan operation, and ends the processing in FIG. 6.

On the other hand, if the structure determination process (S450) using the most recent histogram determines that there is no structural information about the subject image, i.e., if the structure presence/absence flag is set to zero, the movement possibility setting unit 230b makes a negative determination in step S460 and proceeds to step S480 in order to generate a histogram under different setting conditions. In step S480, the condition setting unit 230c shifts the phase of the class boundaries used to generate the histogram. As described above, the condition setting unit 230c shifts the class boundaries by 1/2 the class width compared to the phase (shift amount) set in step S440.

In step S490, the structure determination unit 230e of the camera control unit 230 performs structure determination processing of the subject image based on the histogram generated by the generation unit 230d after phase shifting. The structure determination processing is similar to step S450, so a description thereof will be omitted. As in step S450, the result of the structure presence/absence determination is represented by setting the flag to 1 or 0.

In step S500, the movement permission setting unit 230b of the camera control unit 230 judges whether or not the structure determination unit 230e has determined that there is structural information on the subject image. If the structure determination process (S490) using the most recent histogram determines that there is structural information on the subject image, in other words, if the structure presence/absence flag is set to 1, the movement permission setting unit 230b judges step S500 to be positive and proceeds to step S470. Then, the movement permission setting unit 230b sets the lens movement permission flag for the scan operation and ends the processing in FIG. 6.

On the other hand, if the structure determination process (S490) using the most recent histogram determines that the subject image has no structure, i.e., if the structure presence/absence flag is set to zero, the movement possibility setting unit 230b makes a negative judgment at step S500 and proceeds to step S510 in order to generate a histogram under different set conditions. In step S510, the condition setting unit 230c determines whether a "class scan" has been completed. If a predetermined class has been set, the condition setting unit 230c makes a positive judgment at step S510 and proceeds to step S520, and if a predetermined class has not been set, the condition setting unit 230c makes a negative judgment at step S510 and returns to step S430 in order to set a class different from the class set previously. If the process returns to step S430, the above-mentioned process is repeated.

In step S520, the condition setting unit 230c determines whether or not a "color scan" has been completed. If a predetermined color has been set, the condition setting unit 230c makes a positive judgment at step S520 and proceeds to step S530. If a predetermined color has not been set, the condition setting unit 230c makes a negative judgment at step S520 and returns to step S420 in order to set a color different from the color previously set. If the condition setting unit 230c returns to step S420, the above-mentioned process is repeated.

When proceeding to step S530, the structure determination unit 230e has performed multiple determinations, and as a result, it has been determined that there is no structural information on the subject image in all determinations. Therefore, the movement permission setting unit 230b sets a flag indicating that the lens should not be moved in the scanning operation in step S530, and ends the processing in FIG. 6.

7 is a flowchart for explaining the flow of the structure determination process (S450) using a histogram. The camera control unit 230 starts the process according to the flowchart in FIG.
In step S451, the generation unit 230d of the camera control unit 230 generates a histogram using the imaging pixel signals corresponding to the adopted focus point P in accordance with the above-mentioned setting conditions (1)-(3) set in the condition setting unit 230c.

In step S452, the structure determination unit 230e of the camera control unit 230 detects a first peak and a second peak from the histogram.
In step S453, the structure determination unit 230e determines whether the ratio between the first peak and the second peak in the histogram is equal to or greater than a first threshold value (e.g., 10 times), i.e., whether the above-mentioned determination condition (1) is satisfied. If the determination condition (1) is satisfied, the structure determination unit 230e makes an affirmative determination in step S453 and proceeds to step S454, and if the determination condition (1) is not satisfied, the structure determination unit 230e makes a negative determination in step S453 and proceeds to step S457.

When the process proceeds to step S457, this corresponds to a state in which the outline or pattern of the subject has disappeared due to a large amount of defocus. In step S457, the structure determination unit 230e recognizes that there is structural information about the subject image, sets the structure presence/absence flag to 1, and ends the process shown in FIG. 7.

In step S454, the structure determination unit 230e of the camera control unit 230 calculates the sum of the frequencies of the classes other than the class of the first peak in the histogram, and proceeds to step S455.
In step S455, the structure determination unit 230e determines whether the ratio of the calculated sum in the total frequency is smaller than a second threshold value (e.g., 10%), i.e., whether the above-mentioned determination condition (2) is satisfied. If the determination condition (2) is satisfied, the structure determination unit 230e makes an affirmative determination in step S455 and proceeds to step S456, and if the determination condition (2) is not satisfied, the structure determination unit 230e makes a negative determination in step S455 and proceeds to the above-mentioned step S457.

When the process proceeds to step S456, it corresponds to a state in which the contours or patterns of the subject image necessary for AF calculation are not present or are insufficient. In step S456, the structure determination unit 230e of the camera control unit 230 recognizes that there is no structural information about the subject image, sets the structure presence/absence flag to zero, and ends the process in FIG. 7.

As described above, in the embodiment, the lens movement of the scan operation is performed when the defocus amount cannot be calculated, but this is based on the knowledge that, depending on the subject, the defocus amount may not be calculated even if the lens movement of the scan operation is performed. In other words, if there is structural information in the image of the subject, the defocus amount may be calculated by the lens movement of the scan operation, but if there is no structural information, there is no possibility of the defocus amount being calculated even if the lens movement of the scan operation is performed. Therefore, the presence or absence of structural information in the captured image of the subject determines whether or not the lens movement of the scan operation is possible. If there is no structural information, the lens movement of the scan operation is not performed, eliminating the need for unnecessary lens movement control.

According to the first embodiment described above, the following advantageous effects can be obtained.
(1) The camera control unit 230 mounted on the camera system 1 is equipped with a structure determination unit 230e that determines whether or not structural information is included in the image of the subject light based on the imaging pixel signals from the image sensor 260, which receives and photoelectrically converts the subject light that has passed through the imaging optical system 360 using a plurality of photoelectric conversion units, and outputs a plurality of photoelectrically converted imaging pixel signals, and a movement feasibility setting unit 230b that sets whether or not the imaging optical system 360 can be moved based on the result determined by the structure determination unit 230e.
With this configuration, it is possible to appropriately determine a case where it is unlikely that the defocus amount can be calculated. In addition, since the possibility of moving the photographing optical system 360 is set based on the result of this determination, it is possible to avoid unnecessary scanning operations of the focus lens 361.

(2) The structure determination unit 230e determines whether or not structural information is included in the image of the subject light based on the frequency distribution of multiple imaging pixel signals, and can therefore appropriately determine the presence or absence of structural information in the image of the subject from, for example, the distribution of the signal values of the imaging pixel signals.

(3) The structure determination unit 230e uses a histogram of the intensity values of multiple imaging pixel signals as a frequency distribution, and can therefore appropriately determine the presence or absence of contours, patterns, etc., that indicate structural information of the subject image, based on the frequency distribution of the histogram.

(4) In the camera control unit 230, the generation unit 230d generates multiple histograms with different widths of intensity value classes, and the structure determination unit 230e performs a judgment based on the multiple histograms. By performing a judgment multiple times based on multiple histograms with different classes, it is possible to increase the accuracy of the judgment compared to a case where a judgment is performed only once based on a single histogram.

(5) In the camera control unit 230, the generation unit 230d generates multiple histograms by shifting the class boundaries without changing the width of the intensity value classes, and the structure determination unit 230e performs a determination based on the multiple histograms. By performing a determination multiple times based on multiple histograms with shifted class boundaries, it is possible to increase the accuracy of the determination compared to a case where a determination is performed only once based on a single histogram.

(6) The image sensor 260 has a plurality of first photoelectric conversion units that output image pixel signals based on charges generated by photoelectrically converting light transmitted through a first filter that transmits light of a first wavelength, and a plurality of second photoelectric conversion units that output image pixel signals based on charges generated by photoelectrically converting light transmitted through a second filter that transmits light of a second wavelength. The camera control unit 230 generates, in the generation unit 230d, a first histogram showing the frequency distribution of signal values based on signals from the plurality of first photoelectric conversion units, and a second histogram showing the frequency distribution of signal values based on signals from the plurality of second photoelectric conversion units, and determines, in the structure determination unit 230e, the presence or absence of contours or patterns that indicate structural information of the image of the subject multiple times based on the multiple histograms. By performing determinations based on different conditions multiple times, the accuracy of the determination can be increased compared to a case where a determination based on one histogram is performed only once.

(7) The structure determination unit 230e determines that there are no contours or patterns or the like that indicate structural information of the subject image when the ratio of the first and second most frequent frequencies in the histogram classes is greater than a first threshold value and the ratio of the sum of the frequencies of the second and lower classes to the total frequency is less than a second threshold value. This configuration makes it possible to appropriately determine whether the defocus amount can be calculated or whether there is no possibility of calculating the defocus amount.

(8) The camera control unit 230 as a camera control device mounted on the camera system 1 includes a focus detection unit 230a and an AF signal processing unit 270b that detect the amount of defocus based on the phase difference between a pair of images of a subject formed by light beams passing through different pupils of the shooting optical system 360, and the camera control unit 230 (generation unit 230d) generates a histogram when the focus detection unit 230a cannot detect the amount of defocus.
With this configuration, the generation of the histogram can be limited to cases where the subject image is so blurred that the defocus amount cannot be calculated, even though the subject image has a structure.

(9) When the structure determination unit 230e determines that there is an outline, pattern, etc. that indicates the structure of the image of the subject, the movement possibility setting unit 230b sets the focus lens 361 of the shooting optical system 360 to be movable for scanning, and when the structure determination unit 230e determines that there is no outline, pattern, etc. that indicates the structure of the image of the subject, the movement possibility setting unit 230b sets the focus lens 361 of the shooting optical system 360 to be movable for scanning.
With this configuration, when it is expected that the defocus amount can be calculated, lens movement of the scanning operation of the focus lens 361 is performed, and when it is expected that the defocus amount can be calculated, unnecessary lens movement of the scanning operation of the focus lens 361 can be avoided.

The following modifications are also within the scope of the present invention, and one or more of the modifications may be combined with the above-described embodiment.
(Variation 1)
In the above-described embodiment, a histogram is generated for the employed focus point P, and the presence or absence of structural information of the subject image is determined based on the generated histogram. Alternatively, a histogram may be generated for the employed focus point P and focus points P arranged around the employed focus point P, and the presence or absence of structural information of the subject image may be determined based on the generated histogram. By generating a histogram using imaging pixel signals corresponding to a range wider than the employed focus point P, the presence or absence of structural information of the subject image can be determined based on a wider portion of the subject.

(Variation 2)
In the above-described embodiment, an example has been described in which a photoelectric conversion unit for image generation and a photoelectric conversion unit for focus detection are provided in the image sensor 260. Alternatively, a focus detection module having a photoelectric conversion unit for focus detection may be provided separately from the image sensor 260. For example, a camera system can be configured in which a quick return mirror is provided on the optical path from the interchangeable lens 3 to the image sensor having a photoelectric conversion unit for image generation, and the focus detection module receives light bent by the quick return mirror.

The focus detection module receives an image of a subject formed by a set of light beams that are bent by a quick return mirror and pass through different areas (pupils) of the interchangeable lens 3. The focus detection module photoelectrically converts the set of subject images and outputs focus detection pixel signals that correspond to the luminance distribution of the subject images.

In the second modification, the AF signal processing unit 270b uses the focus detection pixel signals output from the focus detection module to detect the image shift amount (phase difference) of the image of the set of subjects for each focus point P corresponding to the photoelectric conversion unit arranged in the focus detection module, and can calculate the defocus amount for each focus point P.

If the AF signal processing unit 270b has not calculated the defocus amount, the movement permission setting unit 230b proceeds to step S420 in FIG. 6 and performs the processes from step S420 onward to distinguish whether the subject image has structural information but is so blurred that the defocus amount cannot be calculated, or whether the subject image has no structural information.

According to the second modification, even if a focus detection module having a photoelectric conversion unit for focus detection is provided separately from the image sensor 260, the same effect as the above-described embodiment can be obtained.

Second Embodiment
In the second embodiment, in addition to the "phase scan,""classscan," and "color scan" performed in the first embodiment, the presence or absence of structural information in the image of the subject is determined multiple times based on multiple histograms generated by slightly varying the position of the focus lens 361 in the direction of the optical axis O.

Figure 8 is a flow chart illustrating the flow of the process (S40) for determining whether the focus lens 361 can be moved according to the second embodiment. Compared to the determination process (Figure 6) according to the first embodiment, the difference is that steps S525 and S550 are added between steps S520 and S530, so the following explanation will focus on these differences.

In step S525, which is reached after a positive judgment in S520 in FIG. 8, the camera control unit 230 judges whether or not the focus lens 361 has been micro-driven. If the focus lens 361 has been driven a predetermined micro-movement amount, the camera control unit 230 judges S525 as positive and proceeds to step S530, and if the focus lens 361 has not been driven a predetermined micro-movement amount, the camera control unit 230 judges S525 as negative and proceeds to step S550. The micro-movement amount is an amount of movement that is shorter than the amount of movement during scanning movement.

In step S550, the camera control unit 230 causes the body communication unit 240 to send an instruction to the interchangeable lens 3 to micro-drive the focus lens 361 in the direction of the optical axis O, and the process returns to step S420. When the process returns to step S420, the camera control unit 230 repeats the process from step S420 onwards at the position of the focus lens 361 after the micro-drive.

According to the second embodiment described above, in addition to the effects and advantages obtained in the first embodiment, the following effects and advantages are obtained. That is, the structure determination unit 230e of the camera control unit 230 performs a plurality of determinations of structural information of the subject image based on a plurality of histograms generated under increased conditions by minutely driving the focus lens 361, so that the number of times structural information determinations of the subject image are performed increases compared to the case where the focus lens 361 is not minutely driven. Therefore, the presence or absence of structural information of the subject image can be accurately determined based on a greater number of determinations.

(Variation 3)
In the above-described embodiment, a histogram is generated for the adopted focus point P, and whether or not to move the focus lens 361 is determined based on the generated histogram. That is, an example has been described in which the focus point P is adopted before the histogram is generated.
In the third modification, a histogram is generated for all focus points P, and the presence or absence of subject image structural information at each focus point P is determined based on the generated histogram. Then, from among the focus points P determined to have subject image structural information, a focus point P is selected based on the "AF area mode." In other words, the histogram is generated before selecting a focus point P.
With this configuration, it becomes possible to select a focus point to be adopted from among focus points P for which it can be determined that the focus lens 361 can be moved.

The focus detection calculation in variant 3 may employ a contrast detection method (so-called mountain climbing method) instead of a phase difference detection method. In the mountain climbing method, the focus lens 361 is moved to a position where the contrast of the subject image is high. However, if the contours or patterns of the subject image are not clear to begin with, it is difficult to achieve focus using the mountain climbing method. Therefore, by selecting a focus point where it can be determined that the focus lens 361 can be moved, it is possible to make it easier to perform the focus operation using the mountain climbing method.

(Variation 4)
When it is determined in step S460 that there is no structural information, the color, class, and phase set in steps S420, S430, S440, etc. are changed to generate multiple histograms to determine the presence or absence of structural information. However, the presence or absence of structural information in the subject image may be determined using only one histogram obtained with a preset color and class. If step S460 is negative, it may be recognized that there has been no lens movement in the scanning operation of step S530, and the process may be terminated.
(Variation 5)
If the result of step S500 is negative, the class is changed or the color is changed to generate a different histogram and determine whether or not there is structural information. However, if the result of step S500 is negative, it may be recognized that the lens movement in the scanning operation of step S530 has not occurred and the process may be terminated.

1...camera system, 2...camera body, 3...interchangeable lens, 230...camera control unit, 235...storage unit, 260...image sensor, 270...signal processing unit, 280...operation member, 290...display unit, 360...photographic optical system, 361...focus lens, 370...lens drive unit

Claims (12)

a determination unit that determines whether or not structural information is included in an image of the subject light based on a signal from an imaging unit that receives the subject light that has passed through an optical system, photoelectrically converts the received light, and outputs a plurality of photoelectrically converted signals;
a movement permission setting unit that sets a focus lens of the optical system to be movable when the determination unit determines that the structural information is included, and sets a focus lens of the optical system to be movable or not movable when the determination unit determines that the structural information is not included;
a detection unit that detects, by calculation, a defocus amount that is a deviation amount between a focus of the optical system and a position of the imaging unit based on a phase difference between a pair of images formed by light beams that have passed through different pupils of the optical system;
Equipped with
when the detection unit is unable to detect the defocus amount and the movement permission setting unit has set the focus lens to be movable, a signal for moving the focus lens by a predetermined movement amount is transmitted to the optical system, and after the focus lens has moved in response to the signal, a calculation is performed again by the detection unit to detect the defocus amount.
Camera control device. 2. The camera control device according to claim 1,
A camera control device that performs display processing to inform a user that focus driving cannot be performed when the detection unit is unable to detect the defocus amount and the movement feasibility setting unit has set the focus lens as not movable. 3. The camera control device according to claim 1,
A camera control device that does not send an instruction to drive the focus lens to the optical system when the detection unit cannot detect the defocus amount and the movement feasibility setting unit has set the focus lens to be movable or not. 2. The camera control device according to claim 1,
The determination unit performs the determination based on a frequency distribution of the plurality of signals. 5. The camera control device according to claim 4 ,
The camera control device, wherein the determination unit uses a histogram of intensity values of the plurality of signals as the frequency distribution. 6. The camera control device according to claim 5,
A camera control device, wherein the determination unit performs the determination using a plurality of histograms that differ in at least one of the width of the intensity value classes, the phase of the boundaries of the intensity value classes, and the color used to generate the histogram. 7. The camera control device according to claim 6,
The camera control device, wherein the determination unit determines that the structural information is not included when a predetermined condition is satisfied for all of the plurality of histograms. 8. The camera control device according to claim 5 ,
The determination unit generates a plurality of the histograms with different widths of the intensity value classes, and performs the determination based on the plurality of the histograms. 9. The camera control device according to claim 5 ,
The determination unit generates a plurality of the histograms by shifting class boundaries without changing the width of the intensity value classes, and performs the determination based on the plurality of the histograms. 10. The camera control device according to claim 5 ,
the imaging unit includes a plurality of first photoelectric conversion units configured to output signals based on charges generated by photoelectrically converting light transmitted through a first filter that transmits light of a first wavelength, and a plurality of second photoelectric conversion units configured to output signals based on charges generated by photoelectrically converting light transmitted through a second filter that transmits light of a second wavelength,
A camera control device, wherein the judgment unit makes the judgment based on a first histogram based on a plurality of signals from the plurality of first photoelectric conversion units and a second histogram based on a plurality of signals from the plurality of second photoelectric conversion units. 11. The camera control device according to claim 5 ,
The judgment unit determines that the structural information is not included when the ratio of the first and second most frequent frequencies among the intensity value classes is greater than a first threshold value, and the proportion of the sum of the frequencies of the second and lower classes among the total frequencies is smaller than a second threshold value. A camera comprising: the camera control device according to claim 1 ; and the imaging unit .

Images