JP2016167088A - Imaging device and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a focusing display excellent in convenience in an imaging device capable of selection of a main subject.SOLUTION: Subjects are detected from an image to select a main subject from the detected subjects. When the main subject is focused, if the main subject is selected based on an instruction of a user, regardless of a difference between a result of a focus detection for a focus detection area corresponding to the main subject, and a result of the focus detection for a focus detection area corresponding to the subject other than the main subject in a predetermined depth of field, a focusing display for a subject in the predetermined depth of field is displayed so that a display mode of a focusing display for the main subject is different from a display mode of a focusing display for the subject other than the main subject.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an imaging apparatus and a control method thereof, and more particularly to a technique for displaying a subject in focus.

  2. Description of the Related Art Conventionally, some imaging devices, particularly imaging devices having an autofocus function, perform display (focus display) for showing a photographed subject to a photographer.

  In Patent Document 1, it is detected whether or not subjects of a plurality of distance measuring frames are within the depth of field, and display is performed at positions corresponding to the distance measuring frames of subjects existing within the depth of field. Is disclosed.

  Further, in Patent Document 2, in an imaging apparatus that displays a range-finding frame that is determined to be within the depth of field, it is determined whether or not it is within the depth of field according to the focal length of the imaging optical system. It is disclosed that the threshold value of the degree of focus for changing is changed.

JP-A-4-9932 JP-A-5-232371

  According to the prior art, it is easy to confirm the subject within the depth of field, but the screen display may become complicated if there are many displays indicating the subject within the depth of field.

  For example, it is assumed that there are a plurality of subjects at substantially the same distance as the selected main subject at the time of shooting using an imaging device that allows the user to select the main subject. In this case, if display indicating that all of the subjects are within the depth of field is performed, it becomes difficult to identify the main subject, and convenience is impaired.

  The present invention has been made to solve the above-described problems of the prior art, and specifically, an object of the present invention is to realize a convenient focus display in an imaging apparatus capable of selecting a main subject. To do.

  The object described above is to provide detection means for detecting a subject from an image obtained through the lens unit, selection means for selecting a main subject from the subject detected by the detection means, and a focus detection area corresponding to the subject detected by the detection means. Setting means for setting, focus detection means for performing focus detection in the focus detection area set by the setting means, and when the main subject is in focus, if the main subject is selected by the selection means based on a user instruction, The difference between the focus detection result for the focus detection region corresponding to the main subject and the focus detection result for the focus detection region corresponding to the subject other than the main subject within the predetermined depth of field of the lens unit. Regardless of the focus display for the subject within the predetermined depth of field, the focus display for the main subject is displayed for subjects other than the main subject. The focus display of the display mode is achieved by an imaging apparatus characterized by having a display control means for displaying differently.

  With such a configuration, according to the present invention, it is possible to realize an in-focus display that is convenient for an imaging apparatus capable of selecting a main subject.

1 is a block diagram illustrating a configuration example of a digital camera 100 as an example of an imaging apparatus according to a first embodiment of the present invention. 2 is a flowchart illustrating an overall operation of the digital camera 100 according to the first embodiment of the present invention. 4 is a flowchart illustrating an example of a still image recording mode process performed by the digital camera 100 according to the first embodiment of the present invention. It is a flowchart which shows an example of the face detection process which the digital camera 100 concerning the 1st Embodiment of this invention performs. 3 is a flowchart illustrating an example of a photographing process performed by the digital camera 100 according to the first embodiment of the present invention. It is a flowchart which shows an example of the main face selection process which the digital camera 100 concerning the 1st Embodiment of this invention performs. It is a flowchart which shows an example of the focus detection process which the digital camera 100 concerning the 1st Embodiment of this invention performs. It is a flowchart which shows an example of the focus display process which the digital camera 100 concerning the 1st Embodiment of this invention performs. It is a figure which shows the example of the focus display which the digital camera 100 concerning embodiment of this invention performs. It is a figure which shows the example of the through display which the digital camera 100 concerning the 1st Embodiment of this invention performs. It is a flowchart which shows an example of the focus display process which the digital camera 100 concerning the 2nd Embodiment of this invention performs.

Hereinafter, preferred and exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
(First embodiment)
(Configuration of digital camera 100)
FIG. 1 is a block diagram illustrating a configuration example of a digital camera 100 as an example of an imaging apparatus according to the first embodiment of the present invention. However, the imaging apparatus in the present embodiment is not limited to a digital camera, and may be an apparatus that operates as a digital camera. Examples of devices that operate as a digital camera include a digital video camera, a mobile phone with a digital camera, and a personal computer with a digital camera.

  10 is a lens unit, 12 is a shutter having a diaphragm function, 14 is an image sensor that converts an optical image into an electrical signal, and 16 is an A / D converter that digitizes an analog image signal from the image sensor 14 and converts it into image data. It is. Note that a CCD image sensor, a CMOS image sensor, or the like can be used for the image sensor 14.

  The timing generator 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26, and is controlled by the memory controller 22 and the system controller 50.

  The image processing unit 20 performs predetermined pixel interpolation processing and color conversion processing on the image data from the A / D converter 16 or the image data from the memory control unit 22.

  Further, the image processing unit 20 performs predetermined calculation processing using the captured image data. The system control unit 50 controls the exposure control unit 40 and the focusing control unit 42 based on the obtained calculation result, and TTL (through the lens) AF (auto focus), AE (automatic exposure). , EF (flash pre-emission) function is realized.

  Further, the image processing unit 20 performs predetermined calculation processing using the captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained calculation result.

  The memory control unit 22 controls the A / D converter 16, the timing generation unit 18, the image processing unit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression unit 32.

  The output data of the A / D converter 16 is sent to the image display memory 24 or the memory 30 via the image processing unit 20 and the memory control unit 22 or the output data of the A / D converter 16 is directly sent to the memory control unit 22. Is written to.

  Display image data written in the image display memory 24 is displayed by an image display unit 28 such as an LCD or an organic EL display via a D / A converter 26. If the captured image data is sequentially displayed on the image display unit 28, an electronic viewfinder (EVF) function can be realized.

  The image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control unit 50. When the display is turned off, the power consumption of the digital camera 100 can be significantly reduced. it can.

The memory 30 is a storage device for storing captured still images and moving images, and has a storage capacity sufficient to store a predetermined number of still images and a predetermined time of moving images. Therefore, even in the case of continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, a large amount of image writing can be performed on the memory 30 at high speed.
The memory 30 can also be used as a work area for the system control unit 50.

  The compression / decompression unit 32 reads the image data stored in the memory 30, compresses the image data according to a predetermined image compression method, and writes the compressed image data to the memory 30. The compression / decompression unit 32 can also read compressed image data from the memory 30, decompress the image data, and write the decompressed image data into the memory 30. As the predetermined image compression method, an image compression method defined by JPEG, JPEG 2000 or the like may be used, or an image compression method using adaptive discrete cosine transform (ADCT), wavelet transform, or the like may be used. it can.

  The encryption / decryption unit 34 performs an encryption process on image data that has been captured and stored in a predetermined area of the memory 30 as necessary. The encryption / decryption unit 34 performs a decryption process when reproducing and displaying the encrypted image data stored in the predetermined area of the memory 30.

The exposure control unit 40 controls the shutter 12 having a diaphragm function, and also has a flash light control function in cooperation with the flash 48.
The focusing control unit 42 controls the focusing of the lens unit 10, and the zoom control unit 44 controls the zooming of the lens unit 10. The barrier control unit 46 controls the operation of the barrier 102 for protecting the lens unit 10.

The flash 48 functions as an auxiliary light source at the time of photographing and also has a light control function. It also has a function of projecting AF auxiliary light.
The exposure control unit 40 and the focus control unit 42 are controlled using the TTL method. Based on the calculation result obtained by calculating the captured image data by the image processing unit 20, the system control unit 50 performs the exposure control unit 40 and the focus control. The controller 42 is controlled.

  The system control unit 50 is a CPU, for example, and controls the entire digital camera 100 by executing a program stored in the system memory 52. The system memory 52 stores constants, variables, programs, and the like for operating the system control unit 50.

  The display unit 54 is configured by a combination of output devices such as an LCD, an LED, and a speaker, for example, and outputs an operation state, a message, and the like using characters, images, sounds, and the like in accordance with execution of a program by the system control unit 50. . One or a plurality of display units 54 are installed at a position in the vicinity of the operation unit 70 of the digital camera 100 that is easily visible. A part of the display unit 54 is installed in the optical viewfinder 104.

  The display contents of the display unit 54 include, for example, a removal state of the memory card 200, a communication I / F operation state, a connection state with an external computer, and the like. A part of this is displayed in the optical viewfinder 104.

  Of the display contents of the display unit 54, what is displayed by a lamp or the like includes, for example, a self-timer notification lamp. This self-timer notification lamp may be used in common with AF auxiliary light.

  The nonvolatile memory 56 is an electrically erasable / recordable memory, and for example, an EEPROM or the like is used. The nonvolatile memory 56 stores various setting initial values used by the digital camera 100.

  The mode dial 72, the first shutter switch (SW1) 62, the second shutter switch (SW2) 64, the power switch 60, and the operation unit 70 are operations for instructing the system control unit 50 to start and stop a predetermined operation. It is a member. These operation members are composed of buttons, switches, dials, touch panels, line-of-sight detection devices, voice recognition devices, or combinations thereof.

Here, a specific description of these operation members will be given.
The mode dial 72 switches and sets each function mode such as a still image recording mode (automatic shooting mode, program shooting mode, panoramic shooting mode), moving image recording mode, playback mode, multi-screen playback / erase mode, PC connection mode, and the like. It is a switch for.

  The first shutter switch (SW1) 62 is turned on by a first stroke (for example, half-pressed) of a shutter button (not shown) provided in the digital camera 100. When the first shutter switch (SW1) 62 is turned on, AF (autofocus) processing, AE (automatic exposure) processing, AWB (auto white balance) processing, EF processing, and the like are started.

The second shutter switch (SW2) 64 is turned on by a second stroke (for example, full press) of a shutter button provided in the digital camera 100, and instructs to start a series of processes including exposure processing, development processing, and recording processing. . First, in the exposure process, a signal read from the image sensor 14 is written into the memory 30 via the A / D converter 16 and the memory control unit 22, and further, an operation in the image processing unit 20 and the memory control unit 22 is performed. Development processing using is performed. Furthermore, a recording process is performed in which the image data is read from the memory 30, compressed by the compression / decompression unit 32, and written to the memory card 200.
The power switch 60 is a switch for turning on and off the digital camera 100.

  The operation unit 70 is a user interface having operation members such as a switch, a button, a rotary dial switch, and a touch panel. A main face selection button and a main face selection cancel button described later are included in the operation unit 70. The image recording mode, the compression rate, the image quality, and the like of the captured image can be selected using the operation unit 70. Image recording modes include JPEG mode and RAW mode. The JPEG mode is an image recording mode in which a captured image is compressed by the JPEG compression method and recorded on the memory card 200 or the like. The RAW mode is an image recording mode in which digital data obtained by digitizing a signal from the image sensor 14 is recorded on the memory card 200 or the like without being compressed or compressed by a lossless compression method. Note that the compression ratio and image quality in the JPEG mode can be selected by the operation unit 70.

The vertical position detection sensor 75 is a sensor that detects whether the posture of the digital camera 100 is a vertical position or a horizontal position.
The power control unit 80 includes a battery detection circuit, a DC-DC converter, a switch circuit that switches a block to be energized, and the like, and detects whether or not a battery is installed, the type of battery, and the remaining battery level. Further, the power supply control unit 80 controls the DC-DC converter based on the detection results and the instructions of the system control unit 50, and supplies the necessary voltage to each unit including the memory card 200 for a necessary period.

  The power source 86 includes a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, or an AC adapter, and is attached to the digital camera 100 by connectors 82 and 84.

  The memory card 200 is a removable storage medium. As the memory card 200, an SD memory card, a compact flash (registered trademark), a removable HDD, or the like can be used. The memory card 200 includes a memory 202, a camera interface 204, and a connector 206. The memory 202 is a random accessible non-volatile memory. The camera interface 204 can communicate with the card interface 90 on the digital camera 100 side, and the connector 206 can be connected to the connector 92 on the camera side. The insertion and removal of the memory card 200 is detected by a card detection unit (not shown) built in the digital camera 100.

  The barrier 102 covers the imaging unit including the lens unit 10 of the digital camera 100 to prevent the imaging unit from being dirty or damaged.

  The optical finder 104 is, for example, a TTL finder, and forms an image of a light beam that has passed through the lens unit 10 using a prism or a mirror. By using the optical viewfinder 104, it is possible to take a picture without using the electronic viewfinder function of the image display unit 28. Further, as described above, some functions of the display unit 54 such as an in-focus display, a camera shake warning display, a flash charge display, a shutter speed display, an aperture value display, an exposure correction display, etc. are provided in the optical viewfinder 104. Information is displayed.

  The wired communication unit 110 performs communication using RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and the like. The connector 112 is a connector for connecting a cable when the wired communication unit 110 performs communication between the digital camera 100 and an external device.

  The wireless communication unit 114 performs communication using wireless LAN communication such as IEEE802.11a / b / g, Bluetooth (registered trademark), IrDA, or the like. The antenna 116 is used when the wireless communication unit 114 performs communication between the digital camera 100 and an external device.

  The identification information storage unit 118 stores various types of identification information for performing authentication prior to communication when performing wireless communication with an external device (not shown) via the wireless communication unit 114 and the antenna 116. The identification information storage unit 118 is composed of, for example, a rewritable nonvolatile memory.

(Overall operation)
FIG. 2 is a flowchart for explaining the overall operation of the digital camera 100 according to the first embodiment of the present invention.
When the power switch 60 is operated to turn on the power, the system control unit 50 initializes flags, control variables, and the like in S201. During the initialization process, the main face selection flag is canceled. Subsequently, in S <b> 202, the system control unit 50 starts management processing relating to the files recorded on the memory card 200.

  Next, in S203, S205, and S207, the system control unit 50 determines the setting position of the mode dial 72. If the still image recording mode is set, the process proceeds from S203 to S204, and the still image recording mode process is executed. Details of the still image recording mode processing in S204 will be described later with reference to FIG. If the mode dial 72 is set to the moving image recording mode, the process proceeds to S206 via S203 and S205, and the moving image recording mode process is executed. If the mode dial 72 is set to the playback mode, the process proceeds to S208 via S203, S205, and S207, and the playback mode process is executed.

  If another mode has been set, the process proceeds to S209, and the system control unit 50 executes a process according to the selected mode. Other modes include, for example, a transmission mode process for transmitting a file stored in the memory card 200, and a reception mode process for receiving a file from an external device and storing it in the memory card 200.

  After executing the process corresponding to the mode set by the mode dial 72 of S204, S206, S208, and S209, the process proceeds to S210. In S210, the system control unit 50 determines the set position of the power switch 60. If the power switch 60 is set to power on, the process returns to S203. On the other hand, if the power switch 60 is set to power off, the process proceeds from S210 to S211 and the system control unit 50 performs an end process.

  The termination process includes, for example, the following process. That is, the display of the image display unit 28 is changed to an end state, the barrier 102 is closed to protect the lens unit 10, and parameters, setting values, setting modes including flags and control variables are recorded in the nonvolatile memory 56, Shut off the power to parts that do not require power supply. When the termination process of S211 is completed, the system control unit 50 controls the power supply control unit 80 to shift the power supply to the OFF state.

(Still image recording mode)
FIG. 3 is a flowchart showing an example of the still image recording mode process in S204 of FIG.
Note that the still image recording mode process shown in FIG. 3 ends when the mode dial 72 switches to another mode or when the power switch 60 is set to OFF.

When starting the still image recording mode, the system control unit 50 determines the shooting mode in S301. To confirm the shooting mode,
(1) Acquire the shooting mode at the end of the previous still image recording mode from the non-volatile memory 56 and store it in the system memory 52, or
(2) When the operation unit 70 is operated by the user and a shooting mode setting is input, the setting and input shooting mode is stored in the system memory 52.
That is done.

  Here, the shooting mode is a mode realized by combining a shutter speed, an aperture value, a flash emission state, sensitivity setting, and the like suitable for a shooting scene. The digital camera 100 according to the present embodiment has, for example, the following shooting modes.

Auto mode: A mode in which various parameters of the camera are automatically determined by a program incorporated in the digital camera 100 based on the measured exposure value.
-Manual mode: A mode that allows users to freely change various camera parameters.
Scene mode: A combination of shutter speed, aperture value, strobe lighting, sensitivity settings, etc., suitable for the shooting scene is set automatically.

The scene mode includes the following modes.
・ Portrait mode: A mode specialized in portrait photography by blurring the background and making people stand out.
・ Night scene mode: A mode specialized for night scenes, which records the background with a slow shutter speed by applying flashlight to a person.
・ Scenery mode: A mode specialized for a wide landscape scene.
・ Night & Snap mode: Mode suitable for taking beautiful night scenes and people without a tripod.
・ Kids & Pet Mode: A mode that allows you to take pictures of kids and pets that move around without missing a photo opportunity.
-Fresh green & autumn leaves mode: A mode suitable for shooting trees and leaves of fresh green vividly,
-Party mode: A mode that shoots in a color faithful to the subject while suppressing camera shake under a fluorescent light bulb.
・ Snow mode: A mode in which a person does not darken even when the snowy landscape is in the background, and leaves no blue.
・ Beach mode: A mode that allows people to shoot without darkness even on the sea or sandy beaches where sunlight is strongly reflected.
・ Fireworks mode: A mode for shooting fireworks with optimal exposure. ・ Aquarium mode: A mode for setting sensitivity, white balance, and color suitable for shooting fish in an indoor aquarium.
・ Underwater mode: A mode in which the white balance is set to be optimal for underwater, and the image is shot with a tint of blue.

  In S <b> 302, when the shooting mode is determined in S <b> 301, the system control unit 50 subsequently starts through display in which image data from the image sensor 14 is sequentially displayed on the image display unit 28. Thereby, the image display unit 28 functions as an EVF.

  Subsequently, in S303, the system control unit 50 determines whether there is a problem in the operation of the digital camera 100 with the remaining capacity constituted by a battery or the like using the power supply control unit 80, the presence or absence of the memory card 200, and the remaining capacity. Determine. If there is a problem, the system control unit 50 performs a predetermined warning display with an image or sound using the image display unit 28 in S304, and returns the process to S301.

  If there is no problem in the state of the memory card 200, in S305, the system control unit 50 sets an AF frame (focus detection area) as necessary. In the present embodiment, the AF frame is a menu screen (not shown) displayed on the image display unit 28 by pressing a menu button included in the operation unit 70, or an AF frame setting operation member included in the operation unit 70. The user can arbitrarily set by operating.

In the digital camera 100 of the present embodiment, AF frame setting options include:
"Center" with one center frame as AF area,
“Active” in which the user can move the AF area to an arbitrary position by an operation member included in the operation unit 70,
“AiAF”, which sets the 9-frame AF area and performs focusing
“Face priority” to set the AF area according to the detected face position
Is included.

  The system control unit 50 determines whether the AF frame setting is “face priority” (S320), and if it is not “face priority”, the process proceeds to S307. When the AF frame setting is “face priority”, the process proceeds to S306.

  In step S <b> 306, the system control unit 50 performs face detection processing for detecting whether or not a human face (face area) as an example of a subject exists in the through-displayed image. Details of the face detection process as an example of the subject detection process will be described later with reference to FIG. When a face area is detected in the face detection process, the system control unit 50 stores the position coordinates, size (width, height), detected number, reliability coefficient, etc. of the detected face area in the system memory 52 as face information. Remember. If no face area is detected in the face detection process, 0 is set in the face information in the system memory 52. When the face detection process (S306) is completed, the process proceeds to S321.

  In step S <b> 321, the system control unit 50 refers to face information as an example of subject information stored in the system memory 52 and selects a main face area as an example of a main subject from the detected face areas. This main face selection process (S321) will be described later with reference to FIG.

  The main face selection in S321 can also be performed by a user operation. In this embodiment, when the main face is designated by the user operation, the system control unit 50 sets the main face selection flag.

An example of through display by the image display unit 28 is shown in FIG.
FIG. 10A shows a display example when the main face selection flag is not set, that is, when the imaging apparatus automatically determines the main face, and FIG. 10B shows the main face selection flag set. A display example of each case is shown.

  In FIG. 10A, a gray face frame 121 is also displayed in the face area of other subjects (subjects other than the main subject) along with the white face frame 120 indicating the face region of the main subject. In the present embodiment, the upper limit number of face frames displayed during through display is set to 3 because of the display processing load and the display rate. On the other hand, in FIG. 10B, the white face frame 120 is displayed only for the main subject selected by the user.

  Subsequently, in S307, the system control unit 50 determines whether or not the first shutter switch SW1 62 is ON. If the first shutter switch SW1 62 is OFF, the process returns to S305, and the processes of S305 and S306 are repeated.

  On the other hand, if the first shutter switch SW1 62 is ON, in S322, the system control unit 50 controls the focus control unit 42 to perform focus detection processing, and focuses the lens unit 10 on the subject. move on. This focus detection process will be described later with reference to FIG.

  In step S308, the system control unit 50 performs photometry processing to determine an aperture value and a shutter time (shutter speed). In the photometric process, a flash is set if necessary. At this time, if a face (face area) is detected in S306, it is also possible to perform photometry in the detected face range.

  Next, in S323, the system control unit 50 performs in-focus display indicating the focus detection result in S322 on the image display unit 28. Details of the focus display processing will be described later with reference to FIG.

  Next, in S309 and S310, the ON / OFF state of the first shutter switch SW1 62 and the second shutter switch SW2 64 is determined. If the second shutter switch SW2 64 is turned on while the first shutter switch SW1 62 is turned on, the process proceeds from S309 to S311. When the first shutter switch SW1 62 is turned off (when the second shutter switch SW2 64 is not turned on and the first shutter switch SW1 62 is also released), the process returns from S310 to S305. Further, while the first shutter switch SW1 62 is ON and the second shutter switch SW2 64 is OFF, the processes of S309 and S310 are repeated.

  When the second shutter switch SW2 64 is turned on, in S311, the system control unit 50 sets the display state of the image display unit 28 from the through display to the fixed color display state. In step S312, the system control unit 50 controls each unit to perform shooting processing including exposure processing and development processing. In the exposure process, image data obtained through the A / D converter 16 or directly written into the memory 30 from the A / D converter 16. In the development process, the system control unit 50 controls the image processing unit 20 to read out image data written in the memory 30 and perform various processes as necessary. Details of this photographing process will be described later with reference to FIG.

  Next, in step S313, the system control unit 50 performs a quick review process on the image data obtained by the shooting process on the image display unit 28. The quick review process is a process in which image data is displayed on the image display unit 28 for a predetermined time (review time) after shooting of a subject and before recording on the memory card 200 in order to confirm a shot image. is there.

  After the quick review display, in S314, the system control unit 50 executes a recording process for writing the image data obtained by the photographing process to the memory card 200 as an image file.

  When the recording process in S314 ends, in S315, the system control unit 50 determines the ON / OFF state of the second shutter switch SW264. When the second shutter switch SW2 64 is ON, the determination of S315 is repeated, and the process waits for the second shutter switch SW2 64 to be OFF. While the second shutter switch SW2 64 is ON, the display by the quick review process is continued. That is, when the recording process of S314 is completed, the quick review display on the image display unit 28 is continued until the second shutter switch SW2 64 is turned off. With this configuration, the user can carefully check the captured image data displayed in the quick review display by continuing to fully press the shutter button.

  After the user has taken a picture with the shutter button fully pressed and then releases the shutter button, the second shutter switch SW2 64 is turned off, and the process proceeds from S315 to S316. move on. In S316, the system control unit 50 determines whether or not a predetermined minimum display time (minimum review time) for quick review display has elapsed. If the minimum review time has elapsed, the system control unit 50 advances the processing to S317, and if not, waits for the minimum review time to elapse.

  In S317, the system control unit 50 returns the display state of the image display unit 28 from the quick review display to the through display state. With this processing, after the captured image data is confirmed by the quick review display, the display state of the image display unit 28 is automatically switched to a through display state in which image data from the image sensor 14 is sequentially displayed for the next photographing. become.

  In step S318, the system control unit 50 determines whether the first shutter switch SW1 62 is ON / OFF. If the first shutter switch SW1 62 is ON, the process returns to S309, and if it is OFF, the process returns to S305. That is, if the shutter button is half-pressed (the first shutter switch SW1 62 is ON), the system control unit 50 prepares for the next shooting (S309). On the other hand, if the shutter button is released (the first shutter switch SW1 62 is OFF), the system control unit 50 ends the series of shooting operations and returns to the shooting standby state (S305).

(Face detection process)
Next, an example of the face detection process in S306 of FIG. 3 will be described using the flowchart shown in FIG. As described above, face detection processing is an example of subject detection processing, and subject detection may be performed by other methods.

  In step S <b> 401, the system control unit 50 sends face detection target image data from the memory 30 to the image processing unit 20. In step S <b> 402, the image processing unit 20 applies a horizontal bandpass filter to the image data under the control of the system control unit 50. In S403, under the control of the system control unit 50, the image processing unit 20 applies a vertical bandpass filter to the image data processed in S402. By these band pass filter processes in the horizontal and vertical directions, an edge component is detected from the image data.

  After that, in S404, the system control unit 50 performs pattern matching on the detected edge component, and extracts a candidate group of eyes, nose, mouth, and ears. In step S <b> 405, the system control unit 50 selects a pair of candidates that satisfy a preset condition (for example, the distance between two eyes and the inclination) from the eye candidate group extracted in step S <b> 404. An eye detection process is performed to determine that. Then, the system control unit 50 narrows down the eye candidate group by removing candidates that do not form eye pairs.

  In S <b> 406, the system control unit 50 associates the eye candidate group narrowed down in S <b> 405 with other parts (nose, mouth, and ear) that form a face corresponding to the eye candidate group, and sets a predetermined non-face condition. The face (face area) is detected by passing the filter. In step S407, the system control unit 50 calculates face information (face region position coordinates, size (width, height), detected number, reliability coefficient, etc.) as an example of subject information for the face region detected in step S406. Then, the data is stored in the system memory 52 and the process is terminated.

  As described above, it is possible to detect subject information by extracting feature amounts of image data using image data displayed through. In this embodiment, face information is taken as an example of subject information. However, subject information that can be acquired from image data displayed through is various information such as red-eye information.

(Shooting process)
FIG. 5 is a flowchart showing an example of the photographing process in S312 of FIG.
In step S <b> 501, the system control unit 50 acquires the date and time from, for example, a built-in system timer (not shown) at the start of shooting and stores it in the system memory 52. Subsequently, in S502, the shutter 12 having an aperture function is opened according to the aperture value in accordance with the photometric data stored in the system memory 52. Thus, exposure is started (S503).

  In step S504, the system control unit 50 waits for the exposure time according to the photometric data to elapse. When the exposure end time is reached, the system control unit 50 closes the shutter 12 in S505. In step S <b> 506, the charge signal is read from the image sensor 14, and the image data is written in the memory 30 through the A / D converter 16 and the memory control unit 22 or directly from the A / D converter 16. S501 to S506 correspond to the exposure process.

  In step S <b> 507, the system control unit 50 performs image processing on the image data written in the memory 30 using the image processing unit 20 and the compression / decompression unit 32 as necessary. This image processing includes, for example, white balance processing by the image processing unit 20 and compression processing using the compression / decompression unit 32. The image data that has undergone image processing is written into the memory 30.

  In step S <b> 508, the system control unit 50 reads the image data from the memory 30, expands the image data using the compression / decompression unit 32, and resizes the image data for display on the image display unit 28. Then, the resized image data is transferred to the D / A converter 26 for display on the image display unit 28. When a series of processing is finished, the photographing processing is finished.

(Main face selection process)
FIG. 6 is a flowchart showing an example of the main face selection process in S321 of FIG. As described above, the main face selection process is an example of the main subject selection process, and the main subject may be selected by other methods.

  The system control unit 50 determines whether a main face selection button (not shown) included in the operation unit 70 has been operated (ON or OFF) (S601). If ON, the process proceeds to S602, and if OFF, the process proceeds to S608.

  In step S602, the system control unit 50 refers to the number of detected faces (subjects) in the face information stored in the system memory 52. If no face is detected, the process proceeds to step S608. If a face has been detected, the process advances to step S603 to determine whether the number of detected faces is one. Then, the system control unit 50 proceeds to S604 if the number of detected faces is 1, and proceeds to S606 if the number of detected faces is 2 or more.

  In S604, the system control unit 50 sets the only detected face as the main face (S604). Then, the system control unit 50 sets a main face selection flag stored in the system memory 52 or the like (S605), and returns the process to S601.

  When a plurality of faces (subjects) are detected, the system control unit 50 sets one of the plurality of faces as the main face (main subject) in S603. If there is a face already selected as the main face, one (the next one) other than the face currently selected as the main face is set as the main face (S606). Then, a main face selection flag stored in the system memory 52 or the like is set (S607), and the process returns to S601. That is, when a plurality of faces are detected, a plurality of faces are sequentially selected as the main face while the main face selection button is ON. Therefore, the user can select the desired face as the main face (main subject) by keeping the main face selection button ON until the desired face is selected as the main face.

  If the main face selection button is in the OFF state, or if the main face selection button is ON and the number of detected faces is 0, the process proceeds to S608. In step S <b> 608, the system control unit 50 determines whether a main face selection release button (not shown) included in the operation unit 70 has been operated (ON or OFF). If ON, the process proceeds to S609, and if OFF, the process proceeds to S610.

If the main face selection cancel button is ON, the system control unit 50 cancels the main face selection flag stored in the system memory 52 or the like in S608 (S609), and advances the process to S610.
In S610, the system control unit 50 refers to the main face selection flag stored in the system memory 52 or the like, and if the flag is set, ends the main face selection process in S321.

  When the main face selection flag is not set (S610), the system control unit 50 determines the main face based on the face information stored in the system memory 52 (S611), and ends the main face selection process of S321. To do. In S611, for example, if the number of face detection is 0, main face selection is not performed. If the number of detected faces is 1, the detected face is automatically selected as the main face. In addition, when the number of face detections is plural, that is, two or more, the priority is increased as the position is closer to the center of the screen and the size is larger, so that the face with the highest priority among the plurality of faces is selected as the main face. Can be selected. Of course, it goes without saying that the main face may be selected in consideration of not only the position and size but also other information such as reliability.

(Focus detection processing)
FIG. 7 is a flowchart showing an example of the focus detection process in S322 of FIG.
The system control unit 50 determines whether or not the current AF frame setting is “face priority” (S701). If the AF frame setting is other than “face priority”, focus detection processing corresponding to the AF frame setting is performed (S702), and the focus detection processing S322 is terminated.

  On the other hand, if the AF frame setting is “face priority”, the system control unit 50 refers to face information as an example of subject information stored in the system memory 52 in S703. Then, the detected face (face area) is associated (set) with the focus detection area including the center coordinates of each face area (S703). Of the set focus detection areas, those corresponding to the face area of the main face are called main focus detection areas.

  Here, the center coordinates may be, for example, the coordinates of the intersection of the diagonal lines when the face region is rectangular. Alternatively, the coordinates of the center of gravity may be used as the center coordinates. In this specification, a rectangular frame indicating a face area is referred to as a face frame.

  In step S704, the system control unit 50 controls the focusing control unit 42 to perform focus detection in the focus detection region set in step S703. Thereby, focus detection processing is performed in the focus detection area corresponding to each face area. When the focus detection process ends, the system control unit 50 advances the process to S705.

  In S705, the system control unit 50 checks whether or not the main focus detection area, that is, the focus detection area corresponding to the main face is in focus. If it is determined to be in focus, the process proceeds to S706. If not determined, the process proceeds to S708. Proceed with the process.

  In S <b> 706, the system control unit 50 processes the focus detection area included in the depth of field of the focus detection result for the main focus detection area as the focus frame among the focus detection areas associated with the face area in S <b> 703. Advances to S707. In step S707, the system control unit 50 sets the focus detection result in the main focus detection area as the focus position, drives the focus lens of the lens unit 10 to the focus position by the focus control unit 42, and ends the focus detection process.

  On the other hand, in S708, the system control unit 50 determines that there is no in-focus frame, and advances the process to S709. In S709, the system control unit 50 drives the focus lens of the lens unit 10 to a predetermined fixed point by the focus control unit 42, and ends the focus detection process.

  In the flowchart of FIG. 7, when the AF frame setting is “face priority”, it is described that the number of detected faces is 1 or more. However, the number of detected faces is checked between S701 and S703, and the number of detected faces is 0. In this case, the process may be shifted to S708 because there is no focusing frame.

(In-focus display)
FIG. 8 is a flowchart showing an example of the focus display process in S323 of FIG. As described above, the in-focus display is a display indicating the focus detection result for each focus detection area, and indicates either “in-focus” or “out-of-focus”.

  First, in step S801, the system control unit 50 refers to the current AF frame setting. If the AF frame setting is “AiAF” in which nine AF areas are set and a focusing operation is performed, the process proceeds to step S802.

  In S802, the system control unit 50 refers to the result of the focus detection process (S322 and FIG. 7 in FIG. 3), and proceeds to S803 if the result is in focus, and proceeds to S804 if the result is out of focus.

  In step S <b> 803, the system control unit 50 uses the image display unit 28 to focus and display all AF frames (focus detection areas) within the depth of field. The in-focus display can be performed, for example, by superimposing the frame on the image being displayed through, for example, by overwriting the image data stored in the image display memory 24 with the image data of the rectangular frame indicating the AF frame. it can. A display example in S803 is shown in FIG. In FIG. 9A, the three AF frames 122 within the depth are displayed in focus (green frame display).

  In the case of out-of-focus, the system control unit 50 performs neither in-focus frame display nor in-focus frame display on the image display unit 28 in S804. A display example in S804 is shown in FIG.

  If the AF frame setting is not “AiAF” in S801, the system control unit 50 determines whether the AF frame setting is “face priority” in S805. Then, the system control unit 50 advances the process to S806 if the AF frame setting is “face priority”, and advances to S813 otherwise.

  In step S806, the system control unit 50 refers to, for example, the main face selection flag stored in the system memory 52. If the main face selection flag is not set, the system control unit 50 proceeds to step S807.

  In S807, the system control unit 50 refers to the result of the focus detection process (S322 in FIG. 3 and FIG. 7). If the result is in focus (the main focus detection area is in focus), the system control unit 50 may be out of focus. If so, the process proceeds to S809.

In S808, the system control unit 50 uses the image display unit 28 to display all the face frames corresponding to the focus detection area within the depth of field in focus. A display example is shown in FIG. FIG. 9C shows a display example when all the AF frames corresponding to the five subjects are included within the depth of field, and the face frames 123 of the five subjects are similarly displayed in focus ( (Displayed in green frame).
In S809, similarly to S804, the system control unit 50 performs neither in-focus frame display nor in-focus frame display on the image display unit 28. Accordingly, a display example is as shown in FIG.

  In S810, the system control unit 50 refers to the result of the focus detection process (S322 in FIG. 3 and FIG. 7), and if the result is in focus (the main focus detection area is in focus), the process proceeds to S811. The process proceeds to S812.

  In step S811, the system control unit 50 uses the image display unit 28 to display in focus only the face frame corresponding to the main focus detection area, that is, the face area of the main face. A display example is shown in FIG. Here, regardless of the focus state of the focus detection area other than the main focus detection area, the face frame 124 is displayed as the focus display only for the main face, and the focus display (the face frame of the face frame is displayed for the face area other than the main face). (Display) is not performed.

  As described above, when the main face selection flag is set, that is, when the user has set the main face (main subject) himself, only the main face (main subject) is displayed in focus, It becomes possible to easily grasp the selected main face. The in-focus display in S811 may be performed on a face region other than the main face, that is, a subject other than the main subject, as long as the main face set by the user can be identified. For example, as shown in FIG. 9H, the face frame 128 of another face area within the depth of field may be displayed in a form visually different from the face frame 124 for the main face. In the example shown in FIG. 9H, the main face is easily identified by making the face frame 124 for the main face different from the face frame 128 for the other faces. In addition to changing the color, it goes without saying that various methods such as blinking only the face frame 124 of the main face or changing the thickness of the face frame 124 can be used.

  In step S812, the system control unit 50 uses the image display unit 28 to display the face frame of the main face out of focus. A display example is shown in FIG. Here, the display of the face frame 125 of a color different from the focus display (FIG. 9D) of the main face in S811 is set as the out-of-focus display (yellow frame display).

  If the AF frame setting is not “face priority” in S805, the process proceeds to S813, and the system control unit 50 refers to the result of the focus detection process (S322 in FIG. 3 and FIG. 7).

  When the result is in-focus (S813), the system control unit 50 performs in-focus display of the AF frame using the image display unit 28 (S814). Here, it is assumed that the AF frame setting is “center” or “active” and the AF frame is one frame. A display example is shown in FIG. Here, the center AF frame 126 is displayed in focus (green frame display).

  If the result is out-of-focus (S813), the system control unit 50 uses the image display unit 28 to display the AF frame out-of-focus (S815). Here, it is assumed that the AF frame setting is “center” or “active” and the AF frame is one frame. A display example is shown in FIG. The center AF frame 127 is displayed out of focus (yellow frame display).

As described above, according to the present embodiment, in the imaging apparatus capable of setting the main subject from the captured image, the in-focus display related to the main subject is displayed on the other subjects (other than the main subject) included in the depth of field. Visually different from the focus display for the subject. Therefore, even when there are many subjects included within the depth of field, it is easy to determine the in-focus state of the main subject.
In particular, when such a focus display is performed when the user sets a main subject, it becomes easier to grasp the focus state of the main subject intended by the user, which is highly convenient.

(Second Embodiment)
Next, an imaging apparatus according to the second embodiment of the present invention will be described.
Note that the imaging apparatus according to the present embodiment is different from the imaging apparatus described in the first embodiment only in the focus display process (FIGS. 3, S323, and 7), and thus description other than the focus display process is omitted. . The present embodiment is characterized in that the user can perform settings related to in-focus display and perform in-focus display according to this setting (in-focus display setting). For example, the focus display setting is performed by operating a menu screen (not shown) displayed on the image display unit 28 by pressing a menu button included in the operation unit 70 or an operation member for focusing display setting included in the operation unit 70. By doing so, the user can arbitrarily set. For example, it can be set in S305 (FIG. 3) similarly to AF frame setting. The in-focus display setting is stored in, for example, the non-volatile memory 56 similarly to the other setting values.

FIG. 11 is a flowchart illustrating an example of a focus display process performed by the imaging apparatus according to the second embodiment of the present invention.
First, in step S1101, the system control unit 50 refers to the current AF frame setting. If the AF frame setting is “AiAF” in which nine AF areas are set and a focusing operation is performed, the process proceeds to step S1103.

  If the AF frame setting is not “AiAF” in S1101, the system control unit 50 determines in S1102 whether the AF frame setting is “face priority”. Then, the system control unit 50 advances the processing to S1103 if the AF frame setting is “face priority”, and advances to S1110 otherwise.

  In step S <b> 1103, the system control unit 50 refers to, for example, the focus display setting stored in the nonvolatile memory 56 and determines whether the focus display setting is “full display within depth”. If the in-focus display setting is “all display within depth”, the system control unit 50 proceeds to S1104; otherwise, the process proceeds to S1107.

  In S1104, the system control unit 50 refers to the result of the focus detection process (S322 in FIG. 3 and FIG. 7), and if the result is in focus (any of the nine AF frames or the main focus detection area is in focus). If not in focus, the process proceeds to S1106.

In step S1105, the system control unit 50 uses the image display unit 28 to display all the AF frames or face frames included in the depth of field in focus. That is, in accordance with the AF frame setting, in-focus display as shown in FIG. 9A is performed for “AiAF”, and in FIG. 9C for “face priority”.
In S1106, the system control unit 50 does not perform the focused frame display or the non-focused frame display on the image display unit 28 (FIG. 9B).

  If the focus display setting is not “full display within depth”, the system control unit 50 refers to the result of the focus detection process (S322 in FIG. 3 and FIG. 7) in S1107, and if the result is in focus, the process proceeds to S1108. If it is out of focus, the process proceeds to S1109.

  In step S1108, the system control unit 50 uses the image display unit 28 to focus-display the main focus detection area (AF frame) or the corresponding face frame, that is, the face area of the main face. That is, in accordance with the AF frame setting, in-focus display is performed as shown in FIG. 9F for “AiAF” and in FIG. 9D for “face priority”.

  In step S1109, the system control unit 50 uses the image display unit 28 to display the main focus detection area (AF frame) or the corresponding face frame, that is, the face area of the main face out of focus. That is, in accordance with the AF frame setting, in-focus display is performed as shown in FIG. 9G for “AiAF” and in FIG. 9E for “face priority”. As described above, the in-focus display and the out-of-focus display may be different only in the color of the AF frame or the face frame. In this embodiment as well, as in the first embodiment, the focus display is green (or white), and the out-of-focus display is yellow.

  If the AF frame setting is not “face priority” in S1102, the system control unit 50 refers to the result of the focus detection process (S322 in FIG. 3 and FIG. 7) in S1110. If the result is in focus, the process proceeds to S1111. If it is in focus, the process proceeds to S1112.

  In step S1111, the system control unit 50 performs in-focus display of the AF frame using the image display unit 28. Here, it is assumed that the AF frame setting is “center” or “active” and the AF frame is one frame. A display example is shown in FIG. Here, the center AF frame is displayed in focus (green frame display).

  In step S <b> 1112, the system control unit 50 performs an in-focus display of the AF frame using the image display unit 28. Here, it is assumed that the AF frame setting is “center” or “active” and the AF frame is one frame. A display example is shown in FIG. The center AF frame is displayed out of focus (yellow frame display).

  In the first embodiment, the focus display method for the focus detection area corresponding to the main face is determined depending on whether or not the user has set the main face (whether or not the main face selection flag is set). It was a choice. On the other hand, in the present embodiment, the focus display method for the focus detection area corresponding to the main face is selected according to whether the focus display setting is full-depth display.

  In the above-described embodiment, a focus detection area corresponding to the detected face position in the imaging screen is set, and when focus is achieved, the focus detection area corresponding to the face is displayed in focus. A specific subject may be detected by other image detection. For example, it may be possible to cut out and detect a subject image from the background. In addition, the position in the imaging screen may be determined by inputting the position in the imaging screen from an external input unit or detecting the line of sight of the photographer who is looking at the viewfinder.

  In the embodiment described above, the main face selection button and the main face selection release button are dedicated buttons. However, for the main face selection / cancellation operation, a dedicated button is not provided, and for example, it may be possible to cope with the long press of the button used when setting the AF frame or the up / down button. Also, a main face selection button may be provided, and the main face selection cancel operation may be realized by long pressing the main face selection button.

  Also in the present embodiment, it is possible to easily display the in-focus state of the main subject according to the user's intention.

DESCRIPTION OF SYMBOLS 10 ... Lens part, 14 ... Image pick-up element, 20 ... Image processing part, 22 ... Memory control part, 24 ... Image display memory, 40 ... Exposure control part, 42 ... Focus control part, 44 ... Zoom control part, 50 ... System Control unit, 52 ... system memory, 54 ... display unit, 100 ... digital camera

Claims (5)

Detection means for detecting a subject from an image obtained through the lens unit;
Selection means for selecting a main subject from the subjects detected by the detection means;
Setting means for setting a focus detection area according to the subject detected by the detection means;
Focus detection means for performing focus detection in the focus detection area set by the setting means;
When the main subject is in focus, if the main subject is selected by the selection unit based on a user instruction, the focus detection result for the focus detection area corresponding to the main subject, and the lens Regardless of the difference in the focus detection results for the focus detection areas corresponding to subjects other than the main subject within the unit's predetermined depth of field, the unit is within the predetermined depth of field. Display control means for displaying an in-focus display for a subject so that a display form of the in-focus display for the main subject is different from a display form of the in-focus display for a subject other than the main subject;
An imaging device comprising: Detection means for detecting a subject from an image obtained through the lens unit;
Selection means for selecting a main subject from the subjects detected by the detection means;
Setting means for setting a focus detection area according to the subject detected by the detection means;
Focus detection means for performing focus detection in the focus detection area set by the setting means;
Display control means for displaying a result of the focus detection performed by the focus detection means,
The display control means corresponds to the focus detection result corresponding to the focus detection area corresponding to the main subject and the subject other than the main subject within the predetermined depth of field of the lens unit. Regardless of the difference in the focus detection results for the focus detection area, the focus detection results obtained by the focus detection means for the focus detection area corresponding to the main subject and the depth of field of the lens unit. One or more of the results of the focus detection performed by the focus detection means for one or more focus detection areas corresponding to one or more subjects other than the main subject.
An imaging apparatus characterized by that. Detection means for detecting a subject from an image obtained through the lens unit;
Selection means for selecting a main subject from the subjects detected by the detection means;
Setting means for setting a focus detection area according to the subject detected by the detection means;
Focus detection means for performing focus detection in the focus detection area set by the setting means;
Display control means for displaying a result of the focus detection performed by the focus detection means,
The selection means selects the main subject based on subject information acquired for each subject by the detection means based on a user instruction or not based on a user instruction,
The display control means applies the result of the focus detection corresponding to the main subject selected by the selection means based on the user's instruction and the main subject selected by the selection means based on the subject information. The corresponding focus detection results are displayed in different display forms,
The display control means includes the focus detection result for the focus detection area corresponding to the main subject, and the focus detection area corresponding to a subject other than the main subject within the depth of field of the lens unit. (I) the result of the focus detection for the focus detection area corresponding to the main subject, and (ii) other than the main subject within the depth of field Displaying one or more results of said focus detection for one or more focus detection areas corresponding to one or more subjects of
An imaging apparatus characterized by that. Detection means for detecting a subject from an image obtained through the lens unit;
Selection means for selecting a main subject from the subjects detected by the detection means;
Setting means for setting a focus detection area according to the subject detected by the detection means;
Focus detection means for performing focus detection in the focus detection area set by the setting means;
Display control means for displaying a result of the focus detection performed by the focus detection means,
The selection means selects the main subject based on subject information acquired for each subject by the detection means based on a user instruction or not based on a user instruction,
The display control means applies the result of the focus detection corresponding to the main subject selected by the selection means based on the user's instruction and the main subject selected by the selection means based on the subject information. The corresponding focus detection results are displayed in different display forms,
The display control means displays (i) a result of the focus detection for a focus detection area corresponding to the main subject, and (ii) one other than the main subject within the depth of field of the lens unit. Do not display one or more results of the focus detection for one or more focus detection areas corresponding to the subject.
An imaging apparatus characterized by that. Detection means for detecting a subject from an image obtained through the lens unit;
Selection means for selecting a main subject from the subjects detected by the detection means;
Setting means for setting a focus detection area according to the subject detected by the detection means;
Focus detection means for performing focus detection in the focus detection area set by the setting means;
Display control means for displaying a result of the focus detection performed by the focus detection means,
The selection means selects the main subject based on subject information acquired for each subject by the detection means based on a user instruction or not based on a user instruction,
The display control means applies the result of the focus detection corresponding to the main subject selected by the selection means based on the user's instruction and the main subject selected by the selection means based on the subject information. The corresponding focus detection results are displayed in different display forms,
The display control means, if the main subject is selected by the selection means based on the user's instruction, (i) displays the focus detection result for the focus detection area corresponding to the main subject, (Ii) not displaying one or more results of the focus detection for one or more focus detection areas corresponding to one or more subjects other than the main subject within the depth of field of the lens unit;
An imaging apparatus characterized by that.