JP2013205675A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of highly accurately photographing an object as a target.SOLUTION: The imaging apparatus includes imaging means imaging a main object having a feature part, first area specifying means specifying a first area corresponding to the feature part in the imaging range of the imaging means, second area setting means setting a predetermined range as a second area, the predetermined range including the first area specified by the first area specifying means in a part of the predetermined range, determination means determining whether or not a shield object exists in the second area set by the second area setting means, when the main object and the predetermined shield object located closer to the near side than the main object and shieling a part of the main object exist in the imaging range, and imaging control means controlling imaging by the imaging means, based on such a determination made by the determination means that the shield object does not exist in the second area.

Description

  The present invention relates to an imaging apparatus.

  For example, Patent Document 1 describes a camera that assigns priorities to a group of a plurality of focus detection areas and ends the arithmetic processing when a group that satisfies the focus detection evaluation is found.

JP 2000-89091 A

  The camera described in Patent Document 1 has a problem in that when there are a plurality of subjects, the target subject may not be accurately photographed.

According to the first aspect of the present invention, there is provided an imaging means for imaging a main subject having a characteristic part, a first area specifying means for specifying a first area corresponding to the characteristic part in an imaging range of the imaging means, and a first area specifying Second area setting means for setting a predetermined range partially including the first area specified by the means as the second area, a main subject in the imaging range, and one of the main subjects located closer to the main subject. When there is a predetermined shielding subject that blocks the part, a determination unit that determines whether or not there is a shielding subject in the second region set by the second region setting unit, An image pickup apparatus comprising: an image pickup control unit that controls image pickup by the image pickup unit based on a determination that there is no shielding subject.
The invention according to claim 9 is an imaging apparatus for imaging the first subject separated by the second subject, and corresponds to the first subject from the subject image and imaging means for imaging the subject image formed on the imaging surface. A first area detecting means for detecting a first area to be detected, a second area detecting means for detecting a second area corresponding to the second subject from the subject image, a first area detected by the first area detecting means, Determination means for determining whether or not the second area detected by the second area detection means is in a state suitable for imaging the first subject, and suitable for imaging the first subject by the determination means An imaging apparatus comprising: an imaging control unit that controls imaging of a subject image by the imaging unit based on a determination that the image is in a closed state.

  According to the present invention, it is possible to accurately photograph a target subject.

It is a block diagram which shows the structure of the digital camera which concerns on the 1st Embodiment of this invention. 3 is a flowchart of an automatic photographing process executed by a control circuit 110. It is a schematic diagram for demonstrating the condition using an automatic imaging | photography function. 6 is a diagram showing an example of image data displayed on a liquid crystal monitor 161. FIG. 6 is a diagram illustrating an example of determination by an imaging determination unit 113. FIG. It is a flowchart of the automatic imaging | photography process which concerns on 2nd Embodiment. It is sectional drawing which showed the single-lens reflex type digital camera 200 which concerns on the 3rd Embodiment of this invention. FIG. 10 is a diagram showing the arrangement of focus areas of a focus detection device 390. It is a flowchart of the automatic imaging | photography process which concerns on 3rd Embodiment.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of a digital camera according to the first embodiment of the present invention. The digital camera 100 is a lens-integrated digital camera, and has a function of creating image data of a subject image by capturing the subject image formed by the imaging optical system 120 with the image sensor 130.

  The imaging optical system 120 is an optical system including a plurality of lenses including a shake correction lens (not shown) that corrects an image shake of a subject and a focusing lens (not shown) that adjusts a focus state. A subject image is formed on the imaging surface of the image sensor 130. The shake correction lens is configured to be movable in a direction perpendicular to the optical axis of the imaging optical system 120. The focusing lens is configured to be movable in the optical axis direction of the imaging optical system 120.

  The image sensor 130 is an image sensor such as a CCD or CMOS provided with a plurality of photoelectric conversion elements corresponding to pixels. The image sensor 130 captures a subject image formed on the imaging surface and outputs a photoelectric conversion signal (imaging signal) corresponding to the brightness of the subject image. Since R (red), G (green), and B (blue) color filters are provided on the imaging surface of the imaging device 130 so as to correspond to the pixel positions, imaging signals output from the imaging device 130 are provided. Has color information defined by the RGB color system.

  An image pickup signal output from the image pickup device 130 is converted into digital data (image data) by an A / D converter (not shown), and then input to an image processing circuit (not shown), and various types such as contour compensation and gamma correction are performed. Image processing is performed. The image data subjected to these image processes is input to the control circuit 110 shown in FIG.

  The control circuit 110 includes a microprocessor and its peripheral circuits, and is connected to the DRAM 140 and the flash memory 150. The control circuit 110 controls each unit of the digital camera 100 by executing a predetermined control program stored in the flash memory 150 that is a nonvolatile storage medium. The DRAM 140 is used as a temporary storage area by this control program.

  Connected to the control circuit 110 is an input device 180 including various operation members provided outside the digital camera 100 such as a release button (not shown). When the photographer operates each operation member, the input device 180 outputs an operation signal corresponding to the operation member to the control circuit 110. In response to this operation signal, the control circuit 110 executes various operations.

  Further, a focus detection unit 190, a focus adjustment unit 191, a shake correction unit 192, a shake detection unit 193, an LCD drive circuit 160, and a memory card interface (I / F) 170 are connected to the control circuit 110. The focus detection unit 190 detects the focus state of the imaging optical system 120 using image data output from an image processing circuit (not shown) at the subsequent stage of the image sensor 130, and outputs a detection result (focus evaluation value) to the control circuit 110. And output to the focus adjustment unit 191. The focus adjustment unit 191 drives the focusing lens based on the focus detection result so that the main subject is in focus.

  The focus detection unit 190 can detect the contrast of the imaging signal at an arbitrary position in the imaging range of the image sensor 130. The focus detection unit 190 calculates a focus evaluation value at the location based on the detected contrast. The focus adjustment unit 191 adjusts the focus state of the imaging optical system 120 by a so-called hill-climbing method that drives the focusing lens so that the focus evaluation value at the relevant point is maximized.

  The shake detection unit 193 detects the amount of movement of the digital camera 100 in the direction perpendicular to the optical axis of the imaging optical system 120, and outputs a detection signal to the control circuit 110 and the shake correction unit 192. The shake correction unit 192 corrects the image shake of the subject image by driving the shake correction lens based on the detection signal.

  The memory card I / F 170 is an interface for reading and writing data stored in the portable storage medium 171. The LCD drive circuit 160 drives a liquid crystal monitor 161 as a display device, and displays an image or the like on the display screen of the liquid crystal monitor 161 according to an instruction from the control circuit 110. The control circuit 110 stores the image data output from the image processing circuit (not shown) in the storage medium 171 or displays it on the display screen of the liquid crystal monitor 161.

  The image sensor 130 has a through image imaging mode and a main imaging mode. When the through image capturing mode is set in the image sensor 130, the image sensor 130 repeatedly captures a subject image at a predetermined interval (for example, 1/30 second), and repeatedly repeats the image signal to an A / D converter (not shown). ). Each time the imaging signal is output, the A / D converter converts the imaging signal into digital data, and an image processing circuit (not shown) performs image processing accordingly and outputs the image data to the control circuit 110. That is, when the through image capturing mode is set, image data is repeatedly input to the control circuit 110 at predetermined intervals. The control circuit 110 displays the input image data on the display screen of the liquid crystal monitor 161 when the through image capturing mode is set in the image sensor 130.

  For example, when an imaging operation (for example, pressing a release button) is performed by the input device 180, the control circuit 110 sets the imaging device 130 to the main imaging mode and causes the imaging device 130 to perform the main imaging. The control circuit 110 stores the image data obtained by the main imaging in the storage medium 171 and then sets the imaging element 130 to the through image imaging mode again.

  In the present embodiment, the number of pixels (number of pixels) of image data input to the control circuit 110 is different between the through image capturing mode and the main image capturing mode. Specifically, in the through image capturing mode, image data having a smaller number of pixels is input to the control circuit 110 than in the main capturing mode.

  The control circuit 110 includes a main subject detection unit 111, a shielded subject detection unit 112, an imaging determination unit 113, and an imaging control unit 114 in software form. Each of these units is realized by software when the control circuit 110 executes a predetermined control program stored in the flash memory 150. Each of these units is used to realize an automatic photographing function. Hereinafter, an automatic photographing function of the digital camera 100 according to the present embodiment will be described.

(Explanation of automatic shooting function)
The digital camera 100 has an automatic shooting function for automatically shooting when a predetermined condition is satisfied. The photographer can activate the automatic photographing function by operating the input device 180, for example. When the photographer validates the automatic photographing function, the control circuit 110 starts execution of automatic photographing processing described later.

  The automatic shooting function according to the present embodiment has a subject such as a crowd (hereinafter referred to as a shielded subject) that shields the main subject between the subject that the photographer wants to photograph (hereinafter referred to as the main subject) and the photographer. This is a function for reliably photographing the main subject in a situation where Hereinafter, the automatic photographing process executed by the control circuit 110 will be described based on the flowchart.

  FIG. 2 is a flowchart of the automatic photographing process executed by the control circuit 110. First, in step S100, the control circuit 110 inputs a template image of the characteristic part of the main subject to the main subject detection unit 111. The characteristic portion of the main subject is a characteristic subject portion of the main subject used for detecting the main subject. For example, if the main subject is a person, the face of the person can be used as the characteristic portion. . The template image of the feature portion of the main subject may be input to the main subject detection unit 111 in any way, but in this embodiment, the photographer specifies the feature portion from a predetermined still image when using the automatic shooting function. To do. Hereinafter, this point will be described in detail.

  FIG. 3 is a schematic diagram for explaining a situation in which the automatic photographing function is used. As shown in FIG. 3A, the automatic photographing function is useful in a situation where the main subject 10 that the photographer 11 wants to photograph is separated by the crowd 12 that is a shielding subject. At this time, the photographer 11 first performs a shooting operation with the characteristic portion 13 of the main subject 10 included in the shooting range by a method such as lifting the digital camera 100 with both hands as shown in FIG. For example, the release button is pressed). As a result, the control circuit 110 outputs image data including at least the characteristic portion 13 of the main subject 10 as shown in FIG. The control circuit 110 temporarily stores this image data in the DRAM 140 and displays it on the liquid crystal monitor 161.

  FIG. 4 is a diagram illustrating an example of image data displayed on the liquid crystal monitor 161. When the control circuit 110 uses the automatic photographing function, a frame line 20 as shown in FIG. 4A is superimposed on the image data including the characteristic portion 13 of the main subject 10 to divide the image data at equal intervals. indicate. FIG. 4B shows a state in which the frame line 20 in FIG. 4A is superimposed on the image data in FIG. The photographer 11 uses the input device 180 to select one or more blocks 21 including the characteristic portion 13 of the main subject 10 from the plurality of blocks 21 separated by the frame line 20.

  For example, in FIG. 4B, the photographer 11 selects four blocks 21a, 21b, 21c, and 21d including the characteristic portion 13 from a total of 25 blocks divided into 5 rows and 5 columns. The control circuit 110 cuts out areas corresponding to the blocks 21 a, 21 b, 21 c, and 22 d selected by the photographer 11 from the image data stored in the DRAM 140, and uses the main subject as a template image of the characteristic portion 13 of the main subject 10. Input to the detection unit 111. The selection of the block 21 by the photographer 11 may be performed by, for example, a touch operation on the touch panel, or may be performed by a key operation such as a direction key or a determination key.

  Returning to FIG. 2, the description of the automatic photographing process will be continued. In step S110, the control circuit 110 executes an initialization process necessary for the automatic photographing process. Specifically, the control circuit 110 first sets the imaging device 130 to the through image shooting mode, and repeatedly captures a through image by the imaging device 130 at predetermined intervals. In step S <b> 120, imaging in the through image capturing mode is performed by the image sensor 130, and the image data of the through image is output to the control circuit 110.

  In step S130, the main subject detection unit 111 detects a feature portion of the main subject from the through image captured in step S120, and identifies a region including the feature portion of the main subject (hereinafter referred to as a main region). Well-known template matching can be used to detect the feature portion. For example, an area having the same size as the template image input in step S100 is cut out from a position where the through image is present, and a difference for each pixel between the cut-out image and the template image is calculated. This is executed while changing the position little by little with respect to the entire through image, and the position where the total sum of the differences of the calculated pixels is the smallest is determined. If the sum of the differences for each pixel at that position is less than a predetermined threshold, it is estimated that the above-described feature portion exists at that position, and a region slightly larger than the template image so as to surely include the feature portion. Is identified as the main area. On the other hand, if there is no position where the sum of the differences for each pixel is less than the predetermined threshold, it is considered that the characteristic portion of the main subject has not been detected.

  In step S140, the imaging determination unit 113 determines whether or not the characteristic portion of the main subject has been detected in step S130. That is, it is determined whether or not the characteristic range of the main subject is included in the imaging range. If the characteristic part of the main subject cannot be photographed, there is no point in performing the main imaging, and the process returns to step S120. On the other hand, when the characteristic portion of the main subject is included in the through image, the process proceeds to step S150.

  In step S150, the shield subject detection unit 112 detects a shield subject from the through image captured in step S120. In the present embodiment, the shielding subject is a crowd 12 that is located closer to the digital camera 100 than the main subject 10 and blocks a part of the main subject 10 as shown in FIG. The shielding subject detection unit 112 detects such a crowd by a known face recognition process. When the face of a person other than the main subject 10 is recognized from the through image by the face recognition process, it is estimated that a body below the neck of the person exists below the recognition position (vertical direction). Therefore, the shield subject detection unit 112 according to the present embodiment detects the shield subject by treating a region including the recognized face and extending downward in the face as a region where the shield subject exists.

  In step S160, the shielding subject detection unit 112 determines whether or not the main subject is blocked by the shielding subject within a range that includes the main region identified by the main subject detection unit 111 and is larger than the main region. Set to. The shielding determination area is, for example, an area obtained by enlarging the main area vertically and horizontally by a predetermined distance. In the automatic photographing function, photographing is performed so that an extra subject (a shielding subject such as a crowd) does not appear in the shielding determination area.

  When the main area is enlarged and set as the shielding determination area, the distance to be enlarged may be changed depending on the direction. For example, when the main subject is a person and the characteristic portion is the face of the person, it is estimated that a body below the neck of the main subject person exists below the main area (vertical direction). In such a case, it is possible to capture the main subject more appropriately by increasing the amount of enlargement in the downward direction than in the other directions.

  In step S170, the imaging determination unit 113 determines whether or not there is a shielding subject in the shielding determination area. If there is a shielding subject in the shielding determination area, even if the main imaging is performed as it is, the shielding subject will be greatly reflected in the imaging range, and a high-quality photographing result cannot be obtained. Therefore, the main imaging is not performed and the process returns to step S120. On the other hand, if there is no shielding subject in the shielding determination area, the process proceeds to step S180. In step S180, the imaging control unit 114 causes the imaging device 130 to perform main imaging based on the determination by the imaging determination unit 113 that there is no shielding subject in the shielding determination region. Specifically, the imaging device 130 is set to the main imaging mode to perform the main imaging, and the image data of the main imaging is obtained. The obtained image data is stored in the storage medium 171.

  FIG. 5 is a diagram illustrating an example of determination by the imaging determination unit 113. Now, from one through image obtained at a certain time, it is assumed that the shielding determination area 40 is set as shown in FIG. 5A and the shielding subject 50 is detected as shown in FIG. 5B. As is apparent from the figure, the shielding determination area 40 and the shielding subject 50 partially overlap. That is, the shielding subject 50 exists in the shielding determination area 40. Therefore, in the situation shown in FIGS. 5A and 5B, the imaging determination unit 113 makes a negative determination, and the imaging control unit 114 does not perform the main imaging. On the other hand, as shown in FIG. 5C, when the main subject 10 and the shielding subject 12 (such as a crowd) are separated to some extent in the through image, an affirmative determination is made by the imaging determination unit 113, and the main imaging is performed. As a result, as shown in FIG. 5C, image data in which the main subject 10 is not hidden by the shielding subject 12 such as a crowd is obtained.

According to the digital camera according to the first embodiment described above, the following operational effects can be obtained.
(1) The main subject detection unit 111 identifies a main region corresponding to the characteristic part of the main subject. The shielding subject detection unit 112 sets a predetermined range including a main region as a part as a shielding determination region. The imaging determination unit 113 determines whether or not there is a shielding subject in the shielding determination area when the main subject and a shielding subject that is located closer to the main subject and blocks a part of the main subject exist in the imaging range. Determine whether. The imaging control unit 114 controls imaging by the imaging element 130 based on the determination that the shielding subject does not exist in the shielding determination region. Since it did in this way, even if it is a case where a shielding subject exists in an imaging range, the target subject can be image | photographed accurately.

(2) The image sensor 130 has a through image imaging mode for imaging a through image and a main imaging mode for performing actual imaging. The main subject detection unit 111 detects the characteristic portion of the main subject from the through image captured by the image sensor 130 in the through image capturing mode, and identifies the main region based on the result. The shield subject detection unit 112 detects a shield subject from a through image captured by the image sensor 130 in the through image capturing mode. The imaging determination unit 113 determines whether there is a shielding subject in the shielding determination region based on the detection result of the shielding subject by the shielding subject detection unit 112. The imaging control unit 114 causes the imaging device 130 to perform main imaging in the main imaging mode when the imaging determination unit 113 determines that there is no shielding subject in the shielding determination region. Since this is done, the main imaging is not performed in a state where the main subject is hidden behind the shielding subject. Also, since the determination by the imaging determination unit 113 is performed using a through image having a smaller number of pixels than that at the time of actual imaging, the amount of calculation required for detecting the main subject and the shielding subject is reduced.

(3) The shield subject detection unit 112 recognizes a person's face from the through image, and detects a shield subject based on the recognized face position. Since it did in this way, it is not necessary to detect the whole shielding subject by image processing, and a calculation amount is reduced.

(4) The main subject detection unit 111 detects a characteristic portion of the main subject by template matching between the through image and the template image. Since it did in this way, not only a person but all the subjects which have a characteristic part can be made into a main subject.

(5) The main subject detection unit 111 detects an area corresponding to the main subject from the subject image captured by the image sensor 130. The shield subject detection unit 112 detects a region corresponding to the shield subject from the subject image picked up by the image sensor 130. The imaging determination unit 113 determines whether the area corresponding to the main subject and the area corresponding to the shielding subject are in a state suitable for imaging the main subject. The imaging control unit 114 controls the imaging of the subject image by the imaging element 130 based on the determination that the imaging determination unit 113 is suitable for imaging the main subject. Since it did in this way, when it is not a state suitable for imaging of a main subject, imaging is not performed but it becomes possible to always obtain an appropriate imaging result.

(6) The imaging determination unit 113 determines that the main subject and the shielding subject are in a state suitable for imaging the main subject when the shielding subject does not overlap in the shielding determination region. Since it did in this way, an imaging result does not turn into a low quality imaging result in which the main subject was hidden by the shielding subject.

(Second Embodiment)
The digital camera according to the second embodiment to which the present invention is applied has the same configuration as that of the digital camera according to the first embodiment, but executes an automatic photographing process different from that of the first embodiment. Hereinafter, the automatic photographing process executed in the second embodiment will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  FIG. 6 is a flowchart of the automatic photographing process according to the second embodiment. Steps S200 to S250 are the same as steps S100 to S150 in FIG. In step S260, the focus detection unit 190 detects the contrast of the characteristic part of the main subject detected by the main subject detection unit 111, and calculates the focus evaluation value Df1. In step S270, the focus adjustment unit 191 starts driving the focusing lens so as to focus on the feature portion of the main subject based on the focus evaluation value Df1 calculated in step S260.

  In step S280, as in step S160 of FIG. 2, the shielding subject detection unit 112 sets a range that includes the main region and is larger than the main region as the shielding determination region. In step S290, as in step S170 of FIG. 2, the imaging determination unit 113 determines whether or not there is a shielding subject in the shielding determination area. If it is determined that there is a shielding subject, the process proceeds to step S300.

  In step S300, the focus detection unit 190 detects the contrast of the shielding subject detected in step S250, and calculates a focus evaluation value Df2. In step S310, the imaging determination unit 113 compares the absolute value of the focus evaluation value Df1 of the characteristic portion of the main subject with the absolute value of the focus evaluation value Df2 of the shielding subject, and determines whether the former is smaller than the latter. That is, it is determined whether or not the feature portion of the main subject is in focus (whether or not the feature portion of the main subject has a higher contrast than the shielding subject). If the shielded subject is in focus, if the main imaging is performed as it is, image data focused on the shielding subject is output, so the process returns to step S220 without performing the main imaging. On the other hand, when the absolute value of the focus evaluation value Df1 is smaller (in focus by the characteristic part of the main subject), the process proceeds to step S320. If it is determined in step S290 that there is no shielding subject in the shielding determination area, the process also proceeds to step S320.

  In step S320, the imaging determination unit 113 determines whether or not the absolute value of the focus evaluation value Df1 of the feature portion of the main subject is less than a predetermined threshold ε, that is, whether or not the feature portion of the main subject is in focus. To do. If the characteristic portion of the main subject is not in focus, a so-called blurred image can be obtained even if the main imaging is performed, and the process returns to step S220 without performing the main imaging. On the other hand, if the characteristic portion of the main subject is in focus, the process proceeds to step S330.

  In step S330, as in step S180 of FIG. 2, the imaging control unit 114 causes the image sensor 130 to perform main imaging. Specifically, the imaging device 130 is set to the main imaging mode to perform the main imaging, and the image data of the main imaging is obtained. The obtained image data is stored in the storage medium 171.

According to the digital camera according to the second embodiment described above, the following operational effects can be obtained.
(1) The imaging control unit 114 determines that the shielding subject does not exist in the shielding determination region by the imaging determination unit 113, and the focus state detected by the focus detection unit 190 focuses on the characteristic part of the main subject. The image pickup device 130 causes the image pickup device 130 to perform the main image pickup in the main image pickup mode. That is, the imaging determination unit 113 determines that the main subject is suitable for imaging when the focus state detected by the focus detection unit 190 is in a focused state with respect to the main subject. Since it did in this way, it becomes possible to obtain the picked-up image with high contrast of the main subject.

(2) The imaging control unit 114 does not cause the imaging device 130 to perform main imaging in the main imaging mode when the shielding subject is better focused than the main subject. Since it did in this way, in a picked-up image, a shield subject does not stand out from a main subject.

(Third embodiment)
FIG. 7 is a cross-sectional view showing a single-lens reflex digital camera 200 according to the third embodiment of the present invention. FIG. 7 shows only devices and apparatuses according to the present invention, and illustration and description of other devices and apparatuses are omitted. The digital camera 200 includes a camera body 300 and an interchangeable lens 400 that can be attached to and detached from the camera body 300.

  When the interchangeable lens 400 is attached to the camera body 300, the connection portion 302 provided on the lens mount (not shown) is connected to the connection portion 402 provided on the lens mount (not shown) of the interchangeable lens 400. The The connection units 302 and 402 are used for power supply from the camera body 300 to the interchangeable lens 400, transmission / reception of various signals between the camera body 300 and the interchangeable lens 400, and the like.

  The interchangeable lens 400 includes an imaging optical system 120 that includes lenses 120a to 120e. The lenses 120a to 120e include, for example, a focus lens for controlling the focus position of the subject image, a lens for adjusting the focal length of the imaging optical system 120, and the like.

  Inside the interchangeable lens 400, a lens control circuit 403 that controls each part of the interchangeable lens 400 is provided. The lens control circuit 403 includes a microcomputer (not shown), RAM, and peripheral circuits thereof. The lens control circuit 403 is connected to the connection unit 402, and can exchange electrical signals with the camera body 300 via the connection unit 402.

  An imaging element 130 is provided behind the lens mount in the camera body 300. A quick return mirror 308 for guiding subject light to the viewfinder of the camera body 300 is provided between the interchangeable lens 400 and the image sensor 130. A sub mirror 313 is vertically installed on the back side of the quick return mirror 308. At the time of shooting, as indicated by a broken line in FIG. 7, the quick return mirror 308 and the sub mirror 313 are retracted from the shooting optical path. At this time, the subject light transmitted through the imaging optical system 120 enters the image sensor 130 via an exposure state control shutter (not shown) provided in the camera body 300.

  During non-shooting, part of the subject light is guided to the photographer's eyes via the quick return mirror 308, the penta roof prism 311, and the eyepiece 312. Thereby, the photographer can visually recognize the subject image. Further, the remaining part of the subject light passes through the quick return mirror 308 and enters the sub-mirror 313. The sub mirror 313 reflects the subject light and guides it to the focus detection device 390. The focus detection device 390 detects the focus state of the imaging optical system 120, that is, the defocus amount by a so-called phase difference detection method that detects a phase difference between light beams that have passed through a pair of different regions of the imaging optical system 120.

  Inside the camera body 300, a body control circuit 310 that controls each part of the camera body 300 is provided. The body control circuit 310 includes a microcomputer (not shown), a RAM, and peripheral circuits thereof. The body control circuit 310 includes a focus adjustment unit 331, a main subject detection unit 332, a shielded subject detection unit 333, an imaging determination unit 334, and an imaging control unit 335. Each of these functional units is realized in software by the body control circuit 310 executing a predetermined control program.

  The focus adjustment unit 331 functions in the same manner as the focus adjustment unit 191 in the first embodiment. That is, based on the focus state detected by the focus detection device 390, the focusing lens is driven so that the subject is in focus, and the focus state of the imaging optical system 120 is adjusted. The focusing lens is driven by transmitting a lens driving command to the lens control circuit 403 via the connection unit 302. The main subject detection unit 332, the shielding subject detection unit 333, the imaging determination unit 334, and the imaging control unit 335 are also respectively the main subject detection unit 111, the shielding subject detection unit 112, the imaging determination unit 113, and the imaging control unit 335 according to the first embodiment. Since it functions in the same manner as the imaging control unit 114, description thereof is omitted.

  FIG. 8 is a diagram illustrating the arrangement of the focus areas of the focus detection device 390. The focus detection device 390 is configured to be able to calculate the defocus amount at the positions of a plurality of focus areas a provided in the imaging range 50. As shown in FIG. 8, the focus detection device 390 of the present embodiment can calculate the defocus amount for each of 49 focus areas a provided in the entire imaging range 50.

  FIG. 9 is a flowchart of automatic photographing processing according to the third embodiment. First, in step S <b> 400, the body control circuit 310 inputs an area corresponding to the characteristic part of the main subject in the entire imaging range to the main subject detection unit 332. For example, a rectangular area having a predetermined size (a size corresponding to the size of the characteristic part of the main subject) is displayed on the screen, and the photographer moves the rectangular area to a position corresponding to the characteristic part. The body control circuit 310 inputs the result to the main subject detection unit 332.

  In step S420, the focus detection device 390 performs focus detection and calculates the defocus amount of each focus area a. In step S430, the main subject detection unit 332 selects a focus area a (hereinafter referred to as a main focus area) corresponding to the characteristic part of the main subject. In the present embodiment, the focus area a included in the area input in step S400 is selected as the main focus area. When a plurality of focus areas a are included in the area, one appropriate focus area a is selected at the first execution, and the calculation is performed with the focus area a selected at the previous execution at the second and subsequent executions. A focus area a having a defocus amount closest to the defocus amount may be selected.

  In step S450, the shielding subject detection unit 333 sets a predetermined range including the main focus area and wider than the main focus area as the shielding determination region. Note that the area input in step S400 may be used instead of the main focus area.

  In step S460, the occluded subject detection unit 333 selects from 49 focus areas a to one or more focus areas a (included in the area input in step S400) located in the occlusion determination area set in step S450. ) Is selected. The shielding subject detection unit 333 detects that there is a shielding subject that shields the main subject by comparing the defocus amount of the focus area a selected here with the defocus amount of the main focus area. For example, if the defocus amount of the focus area a close to the main focus area is compared with the defocus amount of the main focus area, the digital camera 200 is closer to the position corresponding to the focus area a than the characteristic portion of the main subject. It can be seen that there is a subject located on the side. In this way, the shielded subject detection unit 333 compares the defocus amount of the main focus area with the defocus amount of the focus area a selected in step S460 (the focus area a existing within a certain range from the main focus area). Thus, the shielding subject is detected.

  In step S470, the imaging determination unit 334 determines whether or not there is a shielding subject in the shielding determination area. If there is a shielded subject, the main imaging is not performed, and the process returns to step S420. On the other hand, if there is no shielding subject, the process proceeds to step S480, and the imaging control unit 335 causes the image sensor 130 to perform main imaging.

According to the single-lens reflex type camera according to the third embodiment described above, the following operational effects can be obtained.
(1) The focus detection device 390 calculates the defocus amount in each of the plurality of focus areas a provided in the imaging range. The main subject detection unit 332 selects a main focus area corresponding to the characteristic portion of the main subject from the plurality of focus areas a. The shielding subject detection unit 333 selects a focus area located within the shielding determination region and other than the characteristic portion of the main subject from the plurality of focus areas a. The imaging determination unit 334 compares the defocus amount calculated in the main focus area with the defocus amount calculated in the focus area selected by the shielding subject detection unit 333, so that the shielding subject is in the shielding determination region. Determine if it exists. Since this is done, it is possible to accurately detect the presence of the shielded subject from the distance measurement result by the focus detection device 390, and to accurately photograph the target subject. In addition, it is not necessary to always expose the image sensor 130 for a through image, and the present invention can be applied even to a camera using a reflex mirror as in the present embodiment.

  The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.

(Modification 1)
You may provide the sensor which detects the inclination with respect to the orthogonal | vertical direction of the imaging surface of the image pick-up element 130. FIG. By using such a sensor, it is possible to recognize how far the main subject is from the photographer and the imaging device. For example, if the inclination is steep, it can be determined that the main subject is in the vicinity of the imaging apparatus, and if the inclination is gentle, it is determined that the main subject is far from the imaging apparatus. Based on this determination, for example, it is possible to limit the focusing range by the focus adjustment unit 191 and speed up the focus adjustment. In addition, the imaging control unit 114 can be configured to perform the main imaging only when the tilt detection result is within a predetermined range.

(Modification 2)
In the first embodiment, the main subject may be detected by a method other than template matching with the template image. For example, it may be detected by a known face recognition process. If face recognition processing is used and the main subject and the shielding subject are both persons, the face recognition processing is executed only once, and the main subject and the shielding subject are detected collectively from the result. Is also possible. In this way, it is possible to reduce the amount of calculation required for automatic shooting processing.

(Modification 3)
In each of the embodiments described above, the main subject and the shielding subject are both persons, but the present invention is not limited to such an embodiment. For example, if template matching is used to detect the main subject, any object other than a person can be used as the main subject. Further, as an example of detecting a shielded subject other than a person, for example, if it is a hedge, it may be detected that a green belt-like region is present at the lower part of the imaging range.

(Modification 4)
The conditions for the imaging control unit 114 to perform the main imaging may be conditions other than the presence or absence of the main subject being shielded by the shielding subject and the focusing on the main subject, or a combination of these conditions and other conditions. It may be. For example, the condition that the ratio of the screened subject to the screen is a predetermined value or less, whether the main subject is a person, whether it is facing the front (camera side), the loudness of the environmental sound (above a predetermined amount or a predetermined amount) The following conditions can be used. In addition, when the magnitude of the shake detected by the shake detection unit 193 is equal to or greater than a predetermined amount, control is performed such that the actual imaging is not performed, and when the magnitude of the shake is greater than the predetermined amount, the shutter speed is increased. The image capturing control unit 114 may perform control for suppressing image blur, control for not performing main image capturing until the main subject is moved violently, and the like.

(Modification 5)
In each of the above-described embodiments, the automatic imaging process has been described on the assumption that the main imaging is performed only once in the automatic imaging process. Alternatively, the automatic photographing process may be continued even after the main photographing is performed once. For example, it is possible to set conditions such as continuing the process until the photographer stops the automatic shooting process, continuing the process until a predetermined time elapses, or continuing the process until a predetermined number of images are captured. It is.

(Modification 6)
In the first embodiment, the first imaging (imaging in step S100 in FIG. 2) is not necessarily required. For example, the feature portion of the main subject may be specified from a still image that has already been taken. If the main subject is a person, the feature of the person is registered in advance, and automatic shooting is performed by specifying the person. The function may operate.

(Modification 7)
The automatic shooting process can also be used during moving image shooting. In this case, moving image shooting is started instead of main imaging. That is, recording of a moving image is started when the main subject is in a state suitable for imaging.

(Modification 8)
In the third embodiment, an image sensor different from the image sensor 130 for main imaging may be prepared as a photometric sensor, and the main subject and the shielded subject may be detected by the image sensor.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

DESCRIPTION OF SYMBOLS 100, 200 ... Digital camera, 120 ... Imaging optical system, 130 ... Imaging device, 110 ... Control circuit, 111, 332 ... Main subject detection part, 112, 333 ... Shielding subject detection part, 113, 334 ... Imaging determination part, 114, 335: Imaging control unit, 190: Focus detection unit, 191, 331 ... Focus adjustment unit, 300 ... Camera body, 310 ... Body control circuit, 390 ... Focus detection device, 400 ... Interchangeable lens, 403 ... Lens control circuit

Claims (11)

Imaging means for imaging a main subject having a characteristic part;
First area specifying means for specifying a first area corresponding to the characteristic portion in the imaging range of the imaging means;
Second area setting means for setting a predetermined range including a part of the first area specified by the first area specifying means as a second area;
When the main subject and a predetermined shielding subject that is located closer to the main subject and blocks a part of the main subject are present in the imaging range, the second region setting unit sets the second subject setting unit. Determination means for determining whether or not the shielding subject is present in the second region;
An imaging control unit that controls imaging by the imaging unit based on the determination by the determination unit that the shielding subject does not exist in the second region;
An imaging apparatus comprising: The imaging device according to claim 1,
The imaging means has a through image imaging mode for imaging a through image and a main imaging mode for performing actual imaging,
First detection means for detecting the characteristic portion from the through image captured by the imaging means in the through image capturing mode;
A second detection unit for detecting the shielding subject from the through image captured by the imaging unit in the through image capturing mode;
The first area specifying means specifies the first area based on the detection result of the characteristic portion by the first detecting means,
The determination unit determines whether or not the shielding subject exists in the second region based on the detection result of the shielding subject by the second detection unit,
The imaging apparatus, wherein the imaging control unit causes the imaging unit to perform the main imaging in the main imaging mode when the determination unit determines that the shielding subject does not exist in the second region. The imaging device according to claim 2,
The imaging apparatus according to claim 1, wherein the first detection unit detects the feature portion by template matching between the through image and a predetermined template image. In the imaging device according to claim 2 or 3,
Further comprising face recognition means for recognizing a human face from the through image,
The imaging apparatus according to claim 2, wherein the second detection unit detects the shielding subject based on a face position recognized by the face recognition unit. In the imaging device according to any one of claims 2 to 4,
A focus detection means for detecting the focus state of the imaging optical system;
The imaging control means determines that the shielding subject is not present in the second area by the determination means, and the focus detection means detects that the feature portion of the main subject is in focus. An imaging apparatus that causes an imaging unit to perform the main imaging in the main imaging mode. The imaging device according to claim 1,
A computing means for computing a defocus amount in each of a plurality of focus detection areas provided in the imaging range;
First selection means for selecting a first focus detection area at a position corresponding to the feature portion from the plurality of focus detection areas;
A second selection means for selecting a second focus detection area located in the second region other than the first region from the plurality of focus detection areas;
The determination means compares the defocus amount calculated in the first focus detection area with the defocus amount calculated in the second focus detection area, thereby causing the shielding subject to be included in the second region. It is determined whether or not there is an image pickup apparatus. In the imaging device according to any one of claims 1 to 6,
An imaging apparatus, further comprising: a focus adjusting unit that adjusts a focus state of the imaging optical system so as to focus on a characteristic portion of the main subject. The imaging apparatus according to claim 7,
An inclination detecting means for detecting an inclination of the imaging surface of the imaging means with respect to a vertical direction;
The imaging apparatus according to claim 1, wherein the focus adjustment unit determines a focus adjustment range of the imaging optical system based on the tilt detected by the tilt detection unit. An imaging device for imaging a first subject separated by a second subject,
Imaging means for imaging a subject image formed on the imaging surface;
First area detecting means for detecting a first area corresponding to the first subject from the subject image;
Second area detecting means for detecting a second area corresponding to the second subject from the subject image;
Determining whether the first area detected by the first area detecting means and the second area detected by the second area detecting means are in a state suitable for imaging the first subject. Determination means to perform,
With
An imaging control unit that controls imaging of the subject image by the imaging unit based on the determination by the determination unit that the state is suitable for imaging the first subject;
An imaging apparatus comprising: The imaging device according to claim 9,
The imaging apparatus determines that the first subject and the second subject are in a state suitable for imaging the first subject when the first subject and the second subject do not overlap in the imaging range. The imaging device according to claim 10.
A focus detection means for detecting the focus state of the imaging optical system;
The determination means determines that the focus state detected by the focus detection means is in a state suitable for imaging the first subject when the focus state is in focus with respect to the first subject. An imaging device that is characterized.

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