JP2010054807A - Electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic camera enabling a photographer to continuously track a subject without canceling subject tracking setting even when the subject being tracked comes off from the field because the photographer temporarily turns his (her) eye away from a finder of the electronic camera while tracking the subject. <P>SOLUTION: The electronic camera includes: the finder to confirm the field; an imaging part configured to pick up the image of the field; a tracked subject setting part configured to designate a tracked subject to be tracked as an object to be photographed within the field, and hold photometry information of a photometric area corresponding to the designated tracked subject; a subject tracking part configured to successively extract a photometric area having photometry information similar to the photometry information held by the tracked subject setting part as a tracked subject position out of images continuously picked up by the imaging part; a photographer detection part configured to detect whether or not the photographer looks in the finder; and a tracking operation control part configured to control the subject tracking part to interrupt or restart the extracting operation of the tracked subject position in accordance with a result of detection by the photographer detection part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic camera having a subject tracking function.

In recent years, a specific subject within an object scene to be photographed with an electronic camera has been set as a target for AE (automatic exposure) or AF (autofocus), and is automatically identified even if the specific subject moves within the shooting angle of view. An increasing number of electronic cameras are equipped with a subject tracking function capable of performing AE control and AF control by tracking the position of a subject (for example, see Patent Document 1).
JP-A-5-277850

  However, in the prior art, for example, when the electronic camera is repositioned from a horizontal position to obtain a landscape screen to a vertical position to obtain a portrait screen, the photographer temporarily looks through the viewfinder of the electronic camera. In order to keep away, the subject to be tracked sometimes deviated from the object scene. As a result, the subject tracking cannot be performed and the subject tracking setting is cancelled, so that the subject tracking setting has to be performed again.

  The object of the present invention is that the subject tracking setting is not canceled even if the photographer temporarily takes his eyes off the viewfinder of the electronic camera during subject tracking and the tracking subject falls out of the field of view. And providing an electronic camera capable of subject tracking.

  An electronic camera according to the present invention includes a finder for confirming an object scene, an imaging unit for capturing an image of the object field confirmed by the finder, and a plurality of photometric areas in a matrix form in the object field A photometric unit that divides and performs photometry and outputs photometric information for each photometric area, and specifies a tracking subject to be tracked as a shooting target in the object field, and photometric information of the photometric area corresponding to the specified tracking subject A tracking subject setting unit for holding the subject, and subject tracking for sequentially extracting, as the tracking subject position, a photometry area having photometry information similar to the photometry information held by the tracking subject setting unit from the images continuously captured by the imaging unit A tracking continuation instruction unit for instructing whether or not the photographer continues the extraction operation of the tracking subject position to the subject tracking unit, and whether or not the photographer is looking into the finder. And a tracking continuation instruction unit instructing the continuation operation of the tracking subject position to track the subject tracking unit according to the detection result of the photographer detection unit. And a tracking operation control unit that controls interruption or resumption of the subject position extraction operation.

  Preferably, the tracking operation control unit interrupts the tracking subject position extraction operation with respect to the subject tracking unit when the photographer detection unit detects that the photographer does not look into the viewfinder, When the photographer detection unit detects that the photographer is looking into the viewfinder, the subject tracking unit restarts the tracking subject position extraction operation.

  Preferably, a release button of the electronic camera is used as the tracking continuation instructing unit, and when the release button is in a half-pressed state, the continuation operation of the tracking subject position is instructed. And

  Preferably, an AF start button of the electronic camera is used as the tracking continuation instruction unit, and when the AF start button is in a pressed state, an instruction to continue the tracking subject position extraction operation is given. It is characterized by that.

  Preferably, the photographer detection unit includes an eye sensor that detects whether or not a photographer is in contact with the viewfinder.

  According to the present invention, in an electronic camera having a subject tracking function, even when the photographer temporarily takes his / her eyes off the viewfinder of the electronic camera and the tracking subject is out of the field during subject tracking, The tracking setting is not canceled and subject tracking can be performed continuously.

  Hereinafter, embodiments of an electronic camera according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
In the first embodiment, an example of a single-lens reflex electronic camera 101 provided with an optical viewfinder for confirming a shooting composition of a subject will be described.

  FIG. 1 is a block diagram illustrating a configuration of an electronic camera 101 according to the first embodiment. The electronic camera 101 includes a lens unit 102, a mirror box unit 103, a shutter 104, an image sensor 105, an analog signal processing unit 106, a TG (timing generator) 107, a digital signal processing unit 108, and an image processing unit. 109, bus 110, memory 111, CPU 112, monitor drive unit 113, monitor 114, recording I / F 115, operation unit 116, flash 117, AF sensor 118, AE sensor 119, and eye sensor. 120 and a viewfinder optical system 121. A storage medium such as a memory card 115 a that can be removed from the electronic camera 101 is attached to the recording I / F 115.

  The lens unit 102 includes a photographing optical system 102a including a plurality of lenses and an aperture 102b. The lens unit 102 can be attached to and detached from the main body of the electronic camera 101 and can be replaced with another lens unit. Further, the lens unit 102 changes the aperture 102b and adjusts the focus of the photographing optical system 102a according to a command from the CPU 112.

  The mirror box unit 103 includes a main mirror 103a and a sub mirror 103b. The main mirror 103a is arranged so as to be able to rotate about an axis, and is switched between an observation state and a retracted state by driving the main mirror 103a up and down according to an instruction from the CPU 112. The main mirror 103 a in the observation state is inclined and disposed in front of the image sensor 105. In this observation state, the light beam that has passed through the lens unit 102 is reflected by the main mirror 103a and guided to the finder optical system 121 installed above. The central portion of the main mirror 103a is a half mirror. Then, a part of the light beam transmitted through the main mirror 103a in the observation state is guided to the AF sensor 118 by the sub mirror 103b integrated with the main mirror 103a. On the other hand, the main mirror 103a in the retracted state is in a position that is flipped upward and deviated from the photographing optical path. When the main mirror 103 a is in the retracted state, the light beam that has passed through the lens unit 102 is guided to the image sensor 105. When the recording image (main image) is taken, the main mirror 103a is in the retracted position.

  The finder optical system 121 includes a diffusing screen 131 that projects a subject image so that a photographer can see it, a condenser lens 132, a pentaprism 133, an eyepiece lens 134, a finder window 135, a photometric prism 136, and a photometric lens. 137. In the viewfinder optical system 121, the incident light beam from the subject is divided into two systems: a light beam reaching the eye of the photographer and a light beam reaching the AE sensor 119 in order to measure the light intensity of the object scene. The light beam reaching the photographer's eyes enters the lens unit 102, and the main mirror 103 a of the mirror box unit 103, the diffusion screen 131, the condenser lens 132, the pentaprism 133, the eyepiece lens 134, and the viewfinder window 135. And reach the photographer's eyes. On the other hand, a part of the light beam diffused by the diffusing screen 131 passes through the condenser lens 132, the pentaprism 133, the photometric prism 136, and the photometric lens 137. The AE sensor 119 is reached.

  In addition, the digital signal processing unit 108, the image processing unit 109, the memory 111, the CPU 112, the monitor driving unit 113, and the recording I / F 115 are connected to each other via the bus 110. The lens unit 102, the mirror box unit 103, the shutter 104, the TG 107, the operation unit 116, the flash 117, the AF sensor 118, the AE sensor 119, and the eye sensor 120 are connected to the CPU 112, respectively.

  Here, subject light incident through the lens unit 102, the mirror box unit 103, and the shutter 104 is incident on the light receiving surface of the image sensor 105. A plurality of photoelectric conversion units are arranged in a matrix on the light receiving surface of the image sensor 105. Each photoelectric conversion unit performs photoelectric conversion according to the amount of subject light imaged on the light receiving surface, and generates an analog image signal corresponding to the subject image.

  The analog signal processing unit 106 is an analog front end circuit that performs analog signal processing on the output of the image sensor 105. The analog processing to be executed is, for example, correlated double sampling for noise removal, image signal gain adjustment, and image signal A / D conversion. The output of the analog signal processing unit 106 is connected to the digital signal processing unit 108.

  The TG 107 supplies timing pulses to the image sensor 105 and the analog signal processing unit 106 based on an instruction from the CPU 112. The drive timing of the image sensor 105 and the analog signal processing unit 106 is controlled by the timing pulse of the TG 107.

  The digital signal processing unit 108 performs signal processing such as defective pixel correction and black level offset correction on the digital image signals sequentially input from the analog signal processing unit 106. The output of the digital signal processing unit 108 is connected to the image processing unit 109.

  The image processing unit 109 performs various types of image processing (color interpolation processing, gradation conversion processing, contour enhancement processing, white balance adjustment, etc.). The image processing unit 109 also executes processing for compressing the data of the actual captured image in the JPEG format, and processing for decompressing and restoring the compressed captured image data. The compressed image data is recorded as a captured image on the memory card 115a via the recording I / F 115.

  The memory 111 functions as a buffer memory that temporarily records image data and the like during various image processing. The memory 111 also stores parameters necessary for processing by the CPU 112. For example, in the case of the present embodiment, photometric information and position of the tracking subject are temporarily stored. The photometric information and position of the tracking subject will be described in detail later.

  The CPU 112 is a processor that performs overall control of the electronic camera 101. The CPU 112 controls the operation of each part of the electronic camera 101 according to a program stored in the CPU 112 in advance. Further, the defocus amount is calculated from the output of the AF sensor 118, and the focus position of the photographing optical system 102a of the lens unit 102 is adjusted. Further, exposure calculation is performed from the output of the AE sensor 119, the aperture value of the aperture 102b, the shutter speed of the shutter 104, and the like are determined, and exposure control is performed.

  The monitor driving unit 113 outputs a driving signal based on an instruction from the CPU 112 and displays a captured image or a menu screen on which various setting items can be input in a GUI (Graphical User Interface) format on the monitor 114. The monitor 114 is composed of a liquid crystal monitor, for example. For example, the user performs setting and operation of the electronic camera 101 using various operation buttons included in the operation unit 116 while viewing the menu screen of the monitor 114.

  The recording I / F 115 is equipped with a connector for connecting the memory card 115a and an interface circuit for reading and writing data, and executes writing / reading of image data and the like to / from the memory card 115a connected to the connector.

  As shown in the external view of the electronic camera 101 in FIG. 2, the operation unit 116 includes operation buttons such as a power button 151, a release button 152, an AF start button 153, an OK button 154, four cursor buttons 155 to 158. have. The photographer uses the various operation buttons of the operation unit 116 to switch the shooting mode of the electronic camera 101 and perform an input operation on the menu screen. The release button 152 of the operation unit 116 accepts an input of an AF lock instruction (focus on a subject to be photographed) by a half-press operation, an input of a release instruction (shooting instruction) by a full-press operation, and the like. Here, in the present embodiment, AF control in the continuous AF mode is performed, and the subject to be AF is set in the AF area at a predetermined position (for example, the center of the screen) by half-pressing the release button 152. Thereafter, by maintaining the release button 152 half pressed, the position of the subject to be AF is automatically tracked, and the position of the AF area is also moved accordingly. The setting of the AF target subject (tracking subject) will be described in detail later.

  The flash 117 is an auxiliary light source that emits light based on an instruction from the CPU 112. The CPU 112 controls the light emission time and light emission timing of the flash 117.

  The AF sensor 118 detects the in-focus state in the AF area in the shooting screen by the phase difference detection method.

  The AE sensor 119 is disposed in the vicinity of the pentaprism 133 included in the finder optical system 121, for example. The AE sensor 119 performs split photometry of the subject image based on the light flux of the finder optical system 121. Then, the AE sensor 119 outputs the luminance value and color information for each divided area to the CPU 112.

  Here, the divided areas when the AE sensor 119 performs divided photometry will be described. FIG. 3A is a diagram illustrating a configuration example of a divided region of the AE sensor 119. In the example shown in FIG. 3A, the photometric area 201 of the AE sensor 119 is divided into 165 areas each having 11 rows and 15 columns. For example, when it is desired to set the person 203 on the screen 202 shown in FIG. 3B as the tracking subject, in the present embodiment, the release button is set so that the AF area 204 at the center of the screen of the AF sensor 118 is aligned with the face portion of the person 203. Press 152 halfway. Thereby, the position of the divided area 205 of the AE sensor 119 located in the AF area 204 is set as the position of the tracking subject and stored in the memory 111. Also, photometric information (luminance information, color information, etc.) of the divided area 205 at this time is stored in the memory 111 as tracking subject information. For example, in the photometric area 201 of the AE sensor 119 shown in FIG. 3A, the divided area 205 that is the initial position of the tracking subject is located in the divided area of the sixth row and eighth column of the photometric area 201.

  Here, in the electronic camera 101 according to the present embodiment, as described above, the subject at the fixed AF area position in the center of the screen is set as the tracking subject, but as shown in FIG. As described above, the frame of the AF area 204 may be displayed, and the four cursor buttons 155 to 158 on the top, bottom, left, and right may be operated to set the subject at an arbitrary position on the screen as the tracking subject.

  The eye sensor 120 is a proximity sensor for detecting whether or not the photographer is looking through the finder window 135, and detects whether or not there is any object in the close position. As shown in FIG. 2, the eye sensor 120 is arranged immediately below the viewfinder window 135. When the photographer looks into the viewfinder window 135, the eye sensor 120 is covered with the photographer's face. It is determined that the user is looking through the viewfinder window 135.

  Next, the subject tracking function will be described. As described above, the electronic camera 101 according to the present embodiment uses the continuous AF function in which the AF area moves in accordance with the movement of the subject that performs focus control. In particular, a tracking subject is set by half-pressing the release button 152, and subject tracking processing is started.

  In the electronic camera 101 according to the present embodiment, photometric information (luminance information, color information, etc.) divided by the AE sensor 119 is used to detect the subject to be tracked. For example, it is assumed that the photographer is looking at the screen 202 as shown in FIG. Here, as described with reference to FIG. 3, when the person 203 at the position of the selected AF area 204 is desired to be a tracking subject, the photometric information obtained by the divisional metering in the divided area 205 of the face portion of the person 203 is set as the tracking subject. . When obtaining photometric information of the tracking subject, if there are a plurality of divided areas in the AF area 204, the photometric information of any one divided area may be selected, or the photometric information of the plurality of divided areas is used. It doesn't matter. In the present embodiment, as shown in FIG. 4A, one divided area 205 in the AF area to be tracked is selected, and the metering information divided and measured in the divided area 205 is set as the tracking object, and is stored in the memory 111. Remember.

  Here, as shown in FIG. 4B, when the tracking subject (for example, a person 203) moves in the right direction of the screen 202a, the photometry similar to the photometric information divided by the divided area 205 in FIG. 4A. A divided area having information is detected in the screen 202a of FIG. As a result, the divided area 205a in the screen 202a is detected as a divided area similar to the photometric information obtained by the divided photometry in the divided area 205 in FIG. 4A, and this is set as the position of the new tracking subject. Note that whether or not the photometric information is similar is determined by, for example, whether or not the difference in luminance value is within a predetermined range set in advance, or whether the level difference of each RGB color is within a predetermined range set in advance. Judgment is made depending on whether or not it is accommodated. The luminance information and the color information may be determined using only one of them, or may be determined using both.

  In this way, the electronic camera 101 according to the present embodiment can detect the position of the movement destination even when the position of the tracked subject moves.

  Here, in FIG. 4, the case where the tracking subject always moves within the screen has been described for the sake of easy understanding. However, if the tracking subject protrudes from the screen, the subject tracking cannot be continued. . For example, the electronic camera 101 shown in FIG. 5A changes from a horizontal position to obtain a horizontal screen to a vertical position to obtain a vertical screen as shown in FIG. 5C. When the camera body is picked up again, the photographer temporarily keeps his eyes away from the viewfinder window 135 of the electronic camera 101, so that the tracking subject may be temporarily removed from the field of view as shown in FIG. is there. As a result, the electronic camera 101 cannot continue the subject tracking and the subject tracking setting is cancelled, and the subject tracking setting must be performed again. As shown in FIG. 5B, the electronic camera 101 according to the present embodiment does not cancel the subject tracking setting even if the tracking subject temporarily falls out of the field of view, and continues to the subject. Tracking can be performed.

  Next, the subject tracking operation of the electronic camera 101 according to the present embodiment will be described in detail with reference to the flowchart of FIG. Note that the processing based on the flowchart of FIG. 6 operates according to a program stored in advance in the CPU 112.

  (Step S101) The photographer turns on the power button 151 of the electronic camera 101 and starts photographing. Note that the electronic camera 101 is set in advance to the continuous AF mode. In this state, the CPU 112 puts the main mirror 103a into an observation state, the subject light is projected onto the AF sensor 118, the AE sensor 119, and the finder window 135, and the photographer can check the main subject while looking at the finder window 135.

  (Step S102) The CPU 112 determines whether or not the photographer has pressed the release button 152 halfway. If the release button 152 is half-pressed, the process proceeds to step S103, and if the release button 152 is not half-pressed, the process returns to step S102 to check the shooting composition and the main subject. When the main subject is determined, the photographer presses the release button 152 halfway according to the AF area in the center of the screen.

  (Step S103) The CPU 112 sets the subject in the AF area 204 at the center of the screen as the tracking subject when the release button 152 is half-pressed.

  (Step S104) The CPU 112 performs split photometry with the AE sensor 119.

  (Step S105) The CPU 112 stores, in the memory 111, the photometric information obtained by the divided photometry in the divided area within the AF area from the AE sensor 119 as the tracking subject information. For example, metering information obtained by split metering in the divided area 205 in the AF area 204 at the center of the screen in FIG. 4A is stored in the memory 111 as information on the tracking subject (person 203). At this time, the position of the tracking subject (the position of the divided area 205) is also stored in the memory 111. In addition, the past photometry information of the tracking subject is cleared and overwritten on the newly set photometry information of the tracking subject.

  As described above, the tracking process is started in the processes from step S101 to step S105, and the initial setting of the tracking subject is performed. The following process is a process during tracking.

  (Step S106) The CPU 112 performs split photometry with the AE sensor 119. For example, as shown in the photometry area 201 of FIG. 3A, photometry is performed for each divided area, and photometric information for each divided area is input.

  (Step S <b> 107) The CPU 112 detects a divided area having photometric information similar to the photometric information of the tracking subject stored in the memory 111. For example, a divided area 205a having photometric information similar to the photometric information of the divided area 205 in FIG. 4A is detected in the screen 202a in FIG. 4B.

  In this way, the position of the tracking subject can be updated. In this case, in the photometric area 201 of FIG. 3A, the tracking subject has moved from the position of the divided area 205 to the position of the divided area 205a. As described with reference to FIG. 5B, when the tracking subject deviates from the field of view of the finder window 135, information indicating that the tracking subject is not found is stored in the memory 111. For example, a value indicating the position of the tracking subject is set to a special value such as “FF” so as to indicate that the tracking subject is not found.

  (Step S108) The CPU 112 determines whether or not the photographer has pressed the release button 152 halfway. If the release button 152 is half-pressed, the process proceeds to step S109. If the release button 152 is not half-pressed, it is determined that the tracking operation is stopped, and the process returns to step S102.

  (Step S <b> 109) The CPU 112 determines whether the photographer is looking through the finder window 135 based on the output of the eye sensor 120. If it is detected that the photographer is looking through the finder window 135, the process proceeds to step S110. If it is detected that the photographer is not looking through the finder window 135, the tracking process is interrupted and the process proceeds to step S111.

  (Step S <b> 110) The CPU 112 determines whether or not the tracking subject has deviated from the field of view of the viewfinder window 135. That is, whether or not information indicating that the tracking subject is not found based on the processing result of step S107 is stored in the memory 111 (for example, whether or not the value indicating the position of the tracking subject is “FF”). Is determined. If the tracking subject is not out of the field of viewfinder window 135, the process proceeds to step S114. If the tracking subject is out of the field of viewfinder window 135, the tracking process is interrupted and the process proceeds to step S111.

  (Step S <b> 111) The CPU 112 holds photometric information of the tracking subject stored in the memory 111.

  (Step S112) The CPU 112 determines whether or not the photographer has pressed the release button 152 halfway. If the release button 152 is half-pressed, the process proceeds to step S113. If the release button 152 is not half-pressed, it is determined that the tracking operation is stopped, and the process returns to step S102.

  (Step S <b> 113) The CPU 112 determines whether the photographer is looking into the viewfinder window 135 based on the output of the eye sensor 120. If it is detected that the photographer is not looking through the viewfinder window 135, the process returns to step S112. If it is detected that the photographer is looking through the viewfinder window 135, the tracking process is resumed and the process proceeds to step S106.

  (Step S114) The CPU 112 performs AF processing (focus adjustment) and AE processing (exposure calculation) at a position where the tracking subject is present, and determines shooting conditions such as the aperture value of the aperture 102b and the shutter speed of the shutter 104. For example, in the case of FIG. 4B, AF processing and AE processing are performed at the position of the divided region 205a.

  (Step S115) The CPU 112 determines whether or not the photographer has fully pressed the release button 152. When the release button 152 is fully pressed, the process proceeds to step S116, and when the release button 152 is not fully pressed, the process returns to step S106.

  (Step S116) The CPU 112 performs shooting under the shooting conditions determined in Step S114. For example, in the case of FIG. 4B, the image is taken by the image sensor 105 under the photographing conditions that optimize the focus and exposure with the person 203 in the position of the divided area 205a. An image signal captured by the image sensor 105 is input to the image processing unit 109 via the analog signal processing unit 106 and the digital signal processing unit 108, and is compressed by the image processing unit 109, and the bus 110 and the recording I / F 115. Is stored in the memory card 115a.

  (Step S117) A series of photographing operations is terminated.

  As described above, in the electronic camera 101 according to the present embodiment, as shown in FIGS. 5A to 5C, the position of the vertical position for obtaining the vertically long screen 301 b is changed from the position of the horizontal position for obtaining the horizontally long screen 301. Even when the tracking subject is temporarily removed from the object scene screen 301a when the electronic camera 101 is held again, the subject tracking setting is not canceled. As shown in FIG. 5C, when the tracking subject returns to the screen 301b again, the subject tracking can be resumed and the same subject can be continuously tracked.

  The above embodiment is an example in which the subject tracking function is realized by software processing of the CPU 112, but may be realized by dedicated hardware.

  Next, configuration requirements necessary to realize the subject tracking function of the electronic camera 101 according to the present embodiment will be described. FIG. 7 is a functional block diagram depicting mainly the configuration requirements for realizing the subject tracking function of the electronic camera 101.

  In FIG. 7, the subject tracking function of the electronic camera 101 includes a photometry unit 401, a subject setting unit 402, a tracking frame setting unit 403, a subject information storage unit 404, a subject tracking unit 405, and a tracking continuation instruction unit 406. , A photographer detection unit 407 and a tracking operation control unit 408. At the time of actual shooting, exposure calculation is performed at the tracking subject position obtained from the subject information storage unit 404 to determine shooting conditions, and the imaging unit 410 captures the actual image.

  The photometric unit 401 corresponds to the AE sensor 119 in FIG. 1 and divides the object field into a plurality of divided areas and performs divided photometry, and the photometric information is sent to the subject information storage unit 404, the subject tracking unit 405, and the exposure calculation unit 409. Output.

  The subject setting unit 402 sets a tracking subject by the photographer. In the present embodiment, the subject setting unit 402 is included in the process of step S103 in the flowchart of FIG. 6 and sets the subject in the AF area 204 at the center of the screen as the tracking subject when the release button 152 is half-pressed. To the tracking frame setting unit 403.

  The tracking frame setting unit 403 sets a partial area of the tracking subject selected by the subject setting unit 402 as a tracking subject position (tracking frame), and performs metering of the tracking subject portion in the metering information divided and metered by the metering unit 401. Information is stored as tracking subject information. In the present embodiment, the processing of the tracking frame setting unit 403 corresponds to the processing from steps S103 to S105 in the flowchart of FIG. For example, the divided area 205 in the AF area 204 in FIG. 3B is set as the tracking subject position, and the subject information storage unit 404 uses the photometric information divided by the divided area 205 and the position of the divided area as the tracking subject information. To remember.

  The subject information storage unit 404 corresponds to the memory 111 in FIG. 1 and stores the photometric information and current position of the tracking subject as tracking subject information.

  The subject tracking unit 405 detects a divided region similar to the photometric information of the tracking subject stored in the subject information storage unit 404 from the photometric information for each divided region output by the photometric unit 401 at predetermined intervals. A new tracking subject position is determined. In the present embodiment, the subject tracking unit 405 corresponds to step S107 in the flowchart of FIG. 6, and is similar to, for example, photometric information obtained by performing division photometry in the divided area 205 of FIG. 4A within the screen 202 a of FIG. A divided area 205a having photometric information to be detected is detected, and this is determined as a new position of the tracking subject. The tracking subject position stored in the subject information storage unit 404 is updated every time the tracking subject position is changed by the subject tracking unit 405.

  The tracking continuation instruction unit 406 is a member for instructing the subject tracking unit 405 whether or not to continue the subject tracking operation. In the case of this embodiment, this corresponds to a half-press operation of the release button 152. When the photographer presses the release button 152 halfway, the subject tracking operation is continued. When the photographer releases the release button 152 halfway, the subject tracking operation is stopped.

  The photographer detection unit 407 detects whether or not the photographer is looking through the finder window 135 and outputs the detection result to the tracking operation control unit 408. 1 corresponds to the eye sensor 120 in FIG.

  The tracking operation control unit 408 controls the operation of the subject tracking unit 405 according to the detection results of the tracking continuation instruction unit 406 and the photographer detection unit 407. The present embodiment corresponds to the processing of the entire flowchart of FIG. For example, when the tracking continuation instruction unit 406 instructs to continue the tracking operation of the subject, if the photographer detection unit 407 detects that the photographer is not looking into the finder window 135, the tracking operation of the subject is interrupted. When the photographer detection unit 407 detects that the photographer is looking into the viewfinder window 135, the subject tracking operation is resumed. When the subject tracking operation is interrupted, the photometry information of the tracking subject stored in the subject information storage unit 404 is held as it is.

  The exposure calculation unit 409 corresponds to step S114 in the flowchart of FIG. 6 of the present embodiment, and performs divided photometry in a divided region at a position where the tracking subject obtained from the subject information storage unit 404 is located. When the release button 152 is fully pressed, exposure control is performed with photometric information obtained by split photometry in a divided area where the tracking subject is located, and the main image is captured by the imaging unit 410.

  The imaging unit 410 captures a subject image incident on the imaging element 105 via the lens unit 102, the mirror box unit 103, and the shutter 104 in FIG. 1, and the analog signal processing unit 106, the digital signal processing unit 108, and the image processing unit 109. This corresponds to a series of processing until necessary processing is performed and the actual captured image is stored in the memory card 115a via the recording I / F 115.

  As described above, in the electronic camera 101 according to the present embodiment, when the photographer detection unit 407 detects that the photographer is not looking into the finder window 135 during the subject tracking operation, the operation of the subject tracking unit 405 is performed. When it is interrupted and the photometry information of the tracking subject stored in the subject information storage unit 404 is held and it is detected that the photographer is looking into the viewfinder window 135 again, it is stored in the subject information storage unit 404. The operation of the subject tracking unit 405 is resumed using the photometry information of the tracking subject that is being tracked. As a result, even when the tracking subject is temporarily out of the field, the subject tracking setting is not canceled and the same subject can be continuously tracked.

(Second Embodiment)
Next, an electronic camera 101 according to the second embodiment will be described. Note that the configuration of the electronic camera 101 according to the present embodiment is the same as that in FIGS. 1 and 2 of the first embodiment. The difference from the first embodiment is the subject tracking process shown in the flowchart of FIG. The subject tracking process in the present embodiment operates according to the flowchart shown in FIG. In addition, the process of the same step number as the flowchart of FIG. 6 of 1st Embodiment shows the same process. Here, only a different part from the flowchart of FIG. 6 is demonstrated.

  In the flowchart of FIG. 8, the processing from step S101 to step S113 is the same as the flowchart of FIG. In the present embodiment, when the tracking process is resumed in step S113, the process proceeds to step S201.

  (Step S201) The CPU 112 interrupts the process for a predetermined time and stands by. Specifically, a timer that times out at a predetermined time is operated, and when the timer times out, the process proceeds to the next processing step S106. Here, it is assumed that the set time of the timer is set in advance in the internal memory of the CPU 112 or the memory 111. Note that the set time of the timer is preferably about the time from when the photographer picks up the electronic camera 101 in the portrait orientation from the landscape orientation and starts looking through the viewfinder window 135 until the subject is confirmed again. For example, it may be about several seconds.

  As described above, in the electronic camera 101 according to the present embodiment, as shown in FIGS. 5A to 5C, the position of the vertical position for obtaining the vertically long screen 301 b is changed from the position of the horizontal position for obtaining the horizontally long screen 301. Even when the tracking subject is temporarily removed from the object scene screen 301a when the case of the electronic camera 101 is re-taken, the subject tracking setting is not canceled. As shown in FIG. 5C, when the tracking subject returns to the screen 301b again, the subject tracking can be resumed and the same subject can be continuously tracked. In particular, since the tracking process is kept on standby until the photographer confirms the subject again, the subject tracking can be continued more reliably.

(Third embodiment)
Next, an electronic camera 101 according to the third embodiment will be described. Note that the configuration of the electronic camera 101 according to the present embodiment is the same as that in FIGS. 1 and 2 of the first embodiment. The difference from the first embodiment is the subject tracking process shown in the flowchart of FIG. The subject tracking process in the present embodiment operates according to the flowchart shown in FIG. In addition, the process of the same step number as the flowchart of FIG. 6 of 1st Embodiment shows the same process. Here, only a different part from the flowchart of FIG. 6 is demonstrated.

  In the flowchart of FIG. 9, the processing from step S101 to step S109 is the same as the flowchart of FIG. In this embodiment, the processes after step S109 are partially different. If it is detected in step S113 that the photographer is looking through the viewfinder window 135, the subject tracking is resumed, and the process proceeds to step S301.

  (Step S301) The CPU 112 starts a restart timer that counts a predetermined time, and proceeds to step S106. Here, the restart timer is a timer that counts a predetermined time. For example, the count value is stored in the memory 111, and the count value of the memory 111 is updated every predetermined time. Note that the setting time of the restart timer is preferably about the time from when the photographer picks up the electronic camera 101 in the portrait orientation from the landscape orientation and starts looking through the viewfinder window 135 until the subject is confirmed again. For example, it may be about several seconds as in the second embodiment.

  After this process, the process proceeds to step S106, and the tracking process is continued. Further, in a state where the restart timer is activated, the process proceeds from step S106 to step S109. If it is detected in step S109 that the photographer is looking into the finder window 135, the process proceeds to step S302.

  (Step S302) The CPU 112 reads the count value of the restart timer in the memory 111, and determines whether or not the restart timer has expired after a predetermined time has elapsed. If the resume timer has expired, the process proceeds to step S110. If the resume timer has not expired, the process skips step S110 and proceeds to step S114.

  As described above, in the electronic camera 101 according to the present embodiment, as shown in FIGS. 5A to 5C, the position of the vertical position for obtaining the vertically long screen 301 b is changed from the position of the horizontal position for obtaining the horizontally long screen 301. Even when the tracking subject is temporarily removed from the object scene screen 301a when the casing of the electronic camera 101 is held again, the subject tracking setting is not canceled. As shown in FIG. 5C, when the tracking subject returns to the screen 301b again, the subject tracking can be resumed and the same subject can be continuously tracked. In particular, the resumption timer skips the process of step S110 only for the time until the photographer confirms the subject again, so that subject tracking can be continued more reliably.

  As described above, in the electronic camera 101 according to the present invention, as described above, in the electronic camera 101 according to the present invention, the photographer takes a look away from the finder window 135 of the electronic camera 101 during tracking of the subject, and the tracking subject moves out of the field of view. Even in the event of a failure, the subject tracking setting is not canceled and subject tracking can be performed continuously.

  In each embodiment, the photographer instructs the electronic camera 101 whether or not to perform subject tracking depending on whether or not the release button 152 is half-pressed, but the electronic camera 101 in FIG. The subject tracking may be performed when the AF start button (AF lock button) 153 is pressed, and the subject tracking may be stopped when the AF start button 153 is released. Further, the operation buttons other than the release button 152 and the AF start button 153 may also be used. Alternatively, a dedicated subject tracking button may be provided in the operation unit 116 of the electronic camera 101 so that subject tracking is performed when the subject tracking button is pressed, and subject tracking is stopped when the subject tracking button is released. Absent. In any case, it is desirable that the electronic camera 101 be disposed at a position where the electronic camera 101 can be operated while being gripped.

1 is a block diagram of an electronic camera 101 according to each embodiment. 1 is an external view of an electronic camera 101. FIG. It is explanatory drawing which shows the relationship between the photometry area | region of AE sensor 119, and a tracking subject. It is explanatory drawing which shows the mode of object tracking. It is explanatory drawing which shows the mode of the screen at the time of imaging composition change. It is a flowchart which shows the tracking process of the electronic camera 101 which concerns on 1st Embodiment. It is a functional block diagram which shows the structural requirements which implement | achieve a subject tracking function. It is a flowchart which shows the tracking process of the electronic camera 101 which concerns on 2nd Embodiment. It is a flowchart which shows the tracking process of the electronic camera 101 which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Electronic camera 102 ... Lens unit 103 ... Mirror box unit 104 ... Shutter 105 ... Image pick-up element 106 ... Analog signal processing part 107 ... TG 108 ... Digital signal processing Unit 109 ... Image processing unit 110 ... Bus 111 ... Memory 112 ... CPU
113 ... Monitor drive unit 114 ... Monitor 115 ... Recording I / F 116 ... Operation unit 117 ... Flash 118 ... AF sensor 119 ... AE sensor 120 ... Eye sensor 121. ..Finder optical system 115a... Memory card 102a .. photographing optical system 102b... Stop 131 .. diffusion screen 132 .. condenser lens 133... Pentaprism 134. -Viewfinder window 136 ... Photometric prism 137 ... Photometric lens

Claims (5)

A viewfinder to check the object scene,
An imaging unit that captures an image of an object scene to be confirmed by the viewfinder;
A photometric unit that divides the subject field into a plurality of photometric areas in a matrix and performs divided photometry, and outputs photometric information for each photometric area;
A tracking subject setting unit that specifies a tracking subject to be tracked as a shooting target in the object field, and holds metering information of a metering region corresponding to the designated tracking subject;
A subject tracking unit that sequentially extracts, as a tracking subject position, a photometric area having photometric information similar to the photometric information held by the tracking subject setting unit from images continuously captured by the imaging unit;
A tracking continuation instruction unit for instructing whether or not the photographer continues the extraction operation of the tracking subject position to the subject tracking unit;
A photographer detector for detecting whether a photographer is looking through the viewfinder;
When the tracking continuation instructing unit instructs the continuation of the tracking subject position extracting operation, the tracking subject position extracting operation is interrupted with respect to the subject tracking unit according to the detection result of the photographer detecting unit or An electronic camera comprising: a tracking operation control unit that controls resumption. The electronic camera according to claim 1,
The tracking operation control unit interrupts the subject tracking unit from extracting the tracking subject position when the photographer detection unit detects that the photographer is not looking through the viewfinder, and the photographer detection unit When the photographer detects that the photographer is looking into the viewfinder, the subject tracking unit resumes the tracking subject position extraction operation. The electronic camera according to claim 1 or 2,
An electronic camera using a release button of the electronic camera as the tracking continuation instructing unit, and instructing the continuation of the tracking subject position extracting operation when the release button is in a half-pressed state. The electronic camera according to claim 1 or 2,
An AF start button of the electronic camera is used as the tracking continuation instruction unit, and when the AF start button is in a pressed state, the continuation operation of the tracking subject position is instructed. Electronic camera. The electronic camera according to any one of claims 1 to 4,
The electronic camera, wherein the photographer detection unit includes an eye sensor that detects whether or not a photographer is in contact with the viewfinder.

Images