JP5629533B2 - Imaging apparatus, control method therefor, program, and storage medium - Google Patents

Description

  The present invention relates to autofocus control in an imaging apparatus.

  In recent years, an imaging apparatus such as a digital camera has a function of detecting a subject (for example, a face) having a preset condition, and performs autofocus (hereinafter referred to as AF) control on the subject using the detection result. There is something to do. Also, for example, when multiple faces are detected in the captured image, priorities are assigned based on the size and position of the face, and the focus frame is automatically set to the position of the face with the highest priority (main face). There is a digital camera to do. In this way, it is possible to easily shoot with the focus on the face of the subject.

  Also, if it is temporarily impossible to detect the subject, it will not look good if the frame indicating that the subject has been detected is deleted immediately. One that displays a frame has been proposed (see Patent Document 1).

JP 2009-044661 A

  Focus detection using the above face detection function focuses on the recognized face (main subject), but the main subject is recognized when the main subject no longer exists on the screen (out of frame). There are cases where this is not done. Therefore, if the main subject is not recognized, it may be possible to focus on other subjects present on the screen, but images taken by professional photographers who produce video works such as movies and dramas are considered. When editing, the edit cut point should be a scene with no image movement. For example, if you want to shoot a scene where the main subject is intentionally out of frame, the focus surface that was following the recognized main subject will be out of frame, and the focus surface will immediately move to other subjects. If this happens, the video will be difficult to cut during editing.

  The present invention has been made in view of the above problems, and an object of the present invention is to prevent the main subject from immediately switching to another subject even if the main subject disappears from the screen when there are a plurality of subjects in the screen. It is to realize control technology.

In order to solve the above-described problems and achieve the object, an imaging apparatus of the present invention is generated by an imaging unit that photoelectrically converts a subject image incident via a photographing optical system to generate an imaging signal, and the imaging unit. Subject detection means for detecting a subject having a predetermined characteristic in the photographing screen from the imaging signal , a first AF mode for performing focus adjustment by giving priority to the subject having the predetermined characteristic, A setting means for setting the second AF mode for adjusting the focus only to a subject having a predetermined characteristic; a main subject is selected from the subjects detected by the subject detection means; A main subject selection unit that newly selects a main subject from other subjects existing in the shooting screen and the main subject selection unit. Focus detection means for detecting a focus state for the main subject, a focusing means for performing a focusing operation from the detected in-focus state by said focus detecting means, in the second AF mode, the predetermined in a state where an object having a feature is more detected, the main object to the main object when no longer present in the shooting screen, elapses longer predetermined time than the first AF mode Control means for prohibiting selection of a new main subject by the selection means.

  According to the present invention, when there are a plurality of subjects in the screen, even if the main subject disappears from the screen, the main subject is not immediately switched to another subject. You can shoot.

1 is a block diagram illustrating a configuration of an imaging apparatus according to an embodiment. 6 is a flowchart illustrating a shooting operation according to the first embodiment. 5 is a flowchart illustrating face frame processing according to the first embodiment. 5 is a flowchart illustrating main face selection processing according to the first embodiment. 5 is a flowchart illustrating face frame display processing according to the first embodiment. The figure which shows the example of a face frame display on the display part at the time of face priority AF mode. The figure which shows the example of a face frame display on the display part at the time of AF mode only for a face. The figure which shows the example of a face frame display on the display part at the time of AF mode only for a face. 9 is a flowchart illustrating face frame display processing according to the second embodiment. The figure which shows the example of a face frame display on the display part at the time of AF mode only for a face. The figure which shows the example of a face frame display on the display part at the time of AF mode only for a face. 10 is a flowchart showing face selection processing according to a modification of the first embodiment.

  The best mode for carrying out the present invention will be described in detail below. The embodiment described below is an example for realizing the present invention, and should be appropriately modified or changed according to the configuration and various conditions of the apparatus to which the present invention is applied. It is not limited to the embodiment. Moreover, you may comprise combining suitably one part of each embodiment mentioned later.

  [Embodiment 1] An example in which the image pickup apparatus of the present invention is applied to a digital video camera will be described below, but the present invention is not limited to this and may be applied to a digital still camera or the like.

  <Apparatus Configuration> First, the main configuration of the video camera of this embodiment will be described with reference to FIG.

  In FIG. 1, reference numeral 111 denotes a first fixed lens group, reference numeral 112 denotes a variable magnification lens that moves in the optical axis direction to perform variable magnification and can change the focal length, and reference numeral 113 denotes an aperture. Reference numeral 114 denotes a second fixed lens group, and 115 denotes a focus compensator lens (hereinafter abbreviated as a focus lens) having both a function of correcting the movement of the focal plane accompanying zooming and a function of focusing. The first fixed lens group 111, the variable magnification lens 112, the stop 113, the second fixed lens group 114, and the focus lens 115 constitute the photographing optical system 11.

  The system control unit 14 controls the overall operation of the video camera, and controls each unit according to a predetermined control program in response to an input from the operation unit 134.

  A ROM 167 connected via the bus 15 stores a control program executed by the system control unit 14 and various data necessary for control. The flash ROM 168 stores various setting information relating to the operation of the video camera 10 such as user setting information.

  The SDRAM 166 is used as a work area for the system control unit 14 and a temporary storage area for image data.

  The variable magnification lens 112 is driven by the zoom driving unit 131 and moves back and forth along the optical axis. The focus lens 115 is driven by the focusing drive unit 133 and moves back and forth along the optical axis.

  The system control unit 14 controls the zoom driving unit 131 and the focusing driving unit 133 to control the position of the variable power lens 112 and the position of the focus lens 115, and performs zooming and focusing of the photographing optical system 11.

  The diaphragm 113 is composed of, for example, an iris diaphragm, and is driven by the diaphragm driving unit 132 to operate. The system control unit 14 controls the aperture driving unit 132 to control the aperture amount (aperture value) of the aperture 113 and control the amount of light incident on the image sensor 121.

  The image sensor 121 includes a CMOS sensor or a CCD sensor that photoelectrically converts a subject image incident through the photographing optical system 11 to generate an image signal. The optical image of the subject formed on the light receiving surface of the image sensor 121 by the photographing optical system 11 is converted into signal charges corresponding to the amount of incident light by the photodiode. The signal charge accumulated in each photodiode is sequentially read out from the image sensor 121 as a voltage signal (image signal) corresponding to the signal charge based on a drive pulse supplied from the timing generator (TG) 123 according to a command from the system control unit 14. It is.

  In this embodiment, a CMOS sensor is used as the image sensor 121. However, an image sensor having another configuration such as a CCD sensor may be used.

  The CSD / AGC circuit 122 includes a CDS circuit that performs correlated double sampling processing for removing reset noise (low frequency) included in the image signal output from the image sensor 121, and an image signal output from the image sensor 121. And an AGC circuit for controlling the signal to a certain level.

  The image input controller 124 takes in the image signal output from the CSD / AGC circuit 122 and stores it in the SDRAM 166.

  The signal processing unit 125 takes in an image signal stored in the SDRAM 166 according to a command from the system control unit 14, and performs predetermined signal processing to generate a YUV signal composed of the luminance signal Y and the color difference signals Cr and Cb.

  The subject area detection unit 126 executes subject detection processing on the image signal, specifies the subject area in the shooting screen, and sends the detection result to the system control unit 14. The system control unit 14 sends the detection result to the AF detection unit 165, and the AF detection unit 165 sets a position including the subject region in the shooting screen as a region (focus detection area) used for focus detection. Next, the AF detection unit 165 calculates the degree of focus of the set focus detection area and sends it to the system control unit 14. As the focus adjustment operation, the system control unit 14 controls the focusing drive unit 133 according to the focus degree (focus state) input from the AF detection unit 165, and the focusing drive unit 133 controls the focus lens 115.

  Here, a face detection function is given as an example of the subject detection process described above. This is used in the face priority AF mode in which AF control is performed on the face in the shooting screen detected by the face detection function.

  Here, the face detection function will be described.

  The system control unit 14 sends the image data to be detected to the face processing unit 125. The signal processing unit 125 sends the image data to the subject region detection unit 126, and the subject region detection unit 126 applies a horizontal bandpass filter to the image data. In addition, the subject area detection unit 126 applies a vertical bandpass filter to the processed image data. The edge components of the image data are detected by these horizontal and vertical band pass filters.

  Thereafter, the signal processing unit 125 performs pattern matching on the detected edge component, and extracts eye and nose, mouth, and ear candidates. Then, the signal processing unit 125 determines a pair of eyes that satisfies a preset condition (for example, distance between two eyes, inclination, etc.) from the extracted candidate group of eyes. Narrow down the candidate group only for those with pairs. Then, the signal processing unit 125 associates the narrowed-down eye candidate group with other parts (nose, mouth, ears) that form a face corresponding thereto, and passes a preset non-face condition filter, Detect faces. The signal processing unit 125 outputs the face information according to the face detection result, and ends the processing. At this time, feature quantities such as the number of faces are recorded in the SDRAM 166.

  As described above, it is possible to analyze the image data displayed or reproduced and display the live view, extract the feature amount of the image data, and detect the subject information. In this embodiment, face information is taken as an example of subject information, but there are various information such as non-face feature detection such as animals and balls.

  Also, instead of detecting all faces, a system that detects a subject that applies to a pre-registered facial feature amount as a subject, or a feature amount specified by the photographer from the operation unit 134 such as a touch panel is analyzed and detected. It may be a system that performs.

  <Image Display Processing> Next, image display processing by the video camera 10 will be described with reference to FIGS. In the flowchart described below, the system control unit 14 develops the program stored in the ROM 167 in the work area of the SDRAM 166, and repeatedly executes it, for example, in the readout cycle of the imaging signal from the imaging device 121 for generating one field image. Is done.

  FIG. 2 is a flowchart illustrating image display processing by the video camera according to the first embodiment.

  When a power button (not shown) is operated to turn on the video camera 10 and the startup is completed, in step S1, the system control unit 14 outputs a timing signal generation command to the TG 123, and from the image sensor 121 according to the command. Sequential image signals are read out.

  When the reading of the image signal is completed, the process proceeds to step S2, and the system control unit 14 reads various setting information from the flash ROM 168 via the bus 15, and determines whether or not the mode is a mode in which face detection is performed from the read various setting information. Determine. If it is a mode in which face detection is performed, the process proceeds to face frame processing in step S3.

  In step S3, a face is detected as a subject from the image data read in step S1. Further, a face frame (that is, a region display indicating a subject) is set based on the detected face information, and face frame processing is performed to display the set face frame superimposed on the image data. Details of the face frame processing will be described later with reference to FIGS.

  In step S4, the display control unit 163 superimposes the face frame information generated in step S3 on the image data read out in step S1, and displays it on the display unit 164.

  <Face Frame Processing> Next, the face frame processing in step S3 in FIG. 2 will be described with reference to FIG. FIG. 3 is a flowchart showing the face frame processing in step S3 of FIG.

  In step S31, face detection processing for detecting the face of the subject from the image data read in step S1, the process proceeds to step S32. In step S <b> 31, the system control unit 14 sends image data to the subject area detection unit 126 via the signal processing unit 125. The subject area detection unit 126 detects the face of the subject from the image data, and for all the detected faces, the position and size of the face area, the angle, the likelihood of the face, the number of faces, and other facial feature quantities, etc. The face information is recorded in the SDRAM 166.

  In step S <b> 32, the system control unit 14 selects a face to be a main subject from the detected face information from the face information recorded in the SDRAM 166, and performs main face selection processing to be the main face. This main face selection process constitutes the main subject selection means of the present invention. Details of the main face selection process will be described later with reference to FIG.

  In step S <b> 33, the system control unit 14 performs a face frame indicating the main face area selected in step S <b> 32 (hereinafter, abbreviated as a main face frame) or a main face on the image displayed on the display unit 164. A face frame (hereinafter, abbreviated as a non-main face frame) indicating a region other than is displayed in an overlapping manner. Here, for example, as shown in FIG. 6A, the main face frame 400 and the non-main face frame 401 are displayed so as to overlap the face area. Details of the face frame display processing will be described later with reference to FIG.

  <Main Face Selection Process> Next, with reference to FIG. 4, the main face selection process in step S32 of FIG. 3 will be described.

  In step S321, the system control unit 14 determines whether or not a face is detected in step S31. If not detected, the system control unit 14 proceeds to step S322, and if detected, the process proceeds to step S323.

  In step S322, the system control unit 14 clears the internal face information recorded in the SDRAM 166 and ends the main face selection process. Here, the internal face information is face information held and managed by the system control unit 14 and is data updated by the face information detected in step 31. The internal face information is recorded in the SDRAM 166. The main face is determined to be the main subject from the internal face information by the system control unit 14 in the internal main face forced selection process described later in step S325 and the internal main face automatic selection process described later in step S327. It is face information.

  On the other hand, in step S323, when a face is detected in step S321, the system control unit 14 reads the number of faces from the SDRAM 166, and determines whether the detected face is one or more. When there are a plurality of detected faces, the process proceeds to step S324, and when there is one detected face, the process proceeds to step S329.

  In step S324, the system control unit 14 determines whether a main face switching instruction is input from the photographer to the system control unit 14 via the operation unit 134. When the system control unit 14 receives a main face switching instruction from the photographer, the process proceeds to step S325, and when the system control unit 14 does not receive a main face switching instruction, the process proceeds to step S327.

  In step S325, since the face designated by the photographer via the operation unit 134 is set as the internal main face, the system control unit 14 holds the position and size of the designated face area as internal main face information.

  In step S326, the system control unit 14 writes the internal face information including the internal main face information held in step S325 to the SDRAM 166, and ends the process.

  On the other hand, if the system control unit 14 has not received a main face switching instruction (S324), an internal main face automatic selection process is performed in step S327.

  In step S327, the system control unit 14 reads the face information of all detected faces from the SDRAM 166. Then, the internal main face is determined using at least one piece of information of the position, size, angle, probability, or other feature information of each face area, and is held as internal main face information. .

  In step S328, the system control unit 14 writes the internal face information including the internal main face information held in step S327 to the SDRAM 166, and ends the process.

  In step S329, assuming that only one detected face information is the internal main face, the system control unit 14 overwrites the internal main face information recorded in the SDRAM 166 with the newly detected face information, and ends the process. .

  <Face Frame Display Processing> Next, the face frame display processing in step S33 in FIG. 3 will be described with reference to FIG.

  The system control unit 14 reads the mode setting information from the flash ROM 168, and determines in step S331 whether or not only the face is in the AF mode. When the face only AF mode is selected, the process proceeds to step S334. When the face only AF mode is not selected (hereinafter referred to as face priority AF mode), the process proceeds to step S332. This face priority AF mode corresponds to the first focus adjustment mode of the present invention, and the face only AF mode corresponds to the second focus adjustment mode.

  In step S <b> 332, the system control unit 14 reads the internal face information recorded in the SDRAM 166 and overwrites the area where the display face information of the SDRAM 166 is recorded. Here, the display face information is face information displayed on the display unit 164 by the display control unit 163 superimposing a face frame on the image data read in step S1. However, for non-main faces other than the main face, the system control unit 14 may record all of the internal face information as display face information, or a part of the internal face information including the internal main face information may be displayed face information. May be recorded.

  In step S <b> 333, the system control unit 14 reads display face information from the SDRAM 166 and sends it to the display control unit 163. The display control unit 163 generates face frame data from the display face information input from the system control unit 14 and displays the face frame data on the display unit 164 by superimposing the face frame data on the image data. The main face is displayed differently from the non-main face so that the main face can be seen (see FIG. 6A). In FIG. 6A, the main face frame 400 is displayed with a thicker line than the non-main face frame 401.

  Here, it is assumed that in steps S321 to S328 in FIG. 4, the subject that has been the main face has disappeared from the screen, and the internal main face has been switched. In that case, a transition is made from the state of FIG. 6A to the state of FIG. Further, when AF control is performed with the main face frame as a reference, the AF detection unit 165 detects that the focus detection area has decreased in focus and notifies the system control unit 14 of it. In response to the notification from the AF detection unit 165, the system control unit 14 sends an instruction to drive the focus lens 115 to the focusing drive unit 133. The description of focusing is omitted here.

  If it is determined in step S331 that only the face is in the AF mode, the process proceeds to step S334.

  In step S334, the system control unit 14 determines whether the main face selection prohibition mode is in effect. If it is not in the main face selection prohibition mode, the process proceeds to step S335, and if it is in the main face selection prohibition mode, the process proceeds to step S342. Here, the main face switching count is recorded in the SDRAM 166 and is a value that is initialized to 0 immediately after the power is turned on or after mode switching. In this example, the count is incremented from 0 to 1, 2, 3,..., But the initial value is set to a predetermined value, and then counted down from below a certain threshold value. The subsequent processing may be switched by using the time as a trigger.

  In step S335, the system control unit 14 reads the internal main face information and the display main face information from the SDRAM 166, and compares the positions and sizes of the main face information, the face angles, and the facial feature amounts. Specifically, it is assumed that the face is the same when the difference in the position of the face (for example, the sum of the difference between the x coordinate and the y coordinate) is within the size of the display main face. Also, the same face is assumed when the size of the internal main face is 1.5 times or less than the display main face. Further, when the difference between the angle of the face of the internal main face and the angle of the face of the display main face is within 45 degrees, the same face can be assumed. Furthermore, it is also possible to digitize feature quantities such as the width of both eyes and the feature of the mouth position with respect to the position of the eyes, and if the difference between the values is less than a predetermined difference, the same face can be obtained. Furthermore, it is also possible to comprehensively determine the degree of similarity, assuming that the faces are the same when the sum of the numerical values obtained as described above is within a predetermined amount. Hereinafter, performing the above comparison is expressed as “correlation”, and as a result of the correlation, a state where it can be determined that the faces are the same is expressed as “correlation”.

  As a result of the comparison, when it is determined that the display main face and the internal main face are the same, the process proceeds to step S336, and when it is determined that they are different, the process proceeds to step S341.

  Here, the method for determining whether or not the display main face and the internal main face are the same is the display face information recorded in the SDRAM 166, the position information and size information of the internal main face information updated in FIG. If there is a correlation, it is determined that the faces are the same.

  In step S336, the system control unit 14 reads the display face information and the internal face information from the SDRAM 166, and determines whether or not the display main face information has disappeared. If the display main face has disappeared, the process proceeds to step S337. If not, the process proceeds to step S341. If the display main face information read from the SDRAM 166 by the system control unit 14 is cleared, it can be determined that the display main face has not disappeared but originally did not exist, and the process proceeds to step S337. On the other hand, if the display main face information is not cleared and the correlation between the display main face information and the internal face information fails to correlate with all the data of the internal face information, the display main face is lost. Determination is made and the process proceeds to step S341.

  In step S <b> 337, it is determined whether a main face switching instruction is input from the photographer to the system control unit 14 via the operation unit 134. When the system control unit 14 receives a main face switching instruction, the process proceeds to step S341. When the system control unit 14 does not receive a main face switching instruction, the process proceeds to step S338.

  In step S338, the system control unit 14 clears the display main face information recorded in the SDRAM 166, and proceeds to step S339. By this processing, even when there are a plurality of display face information, there is no display main face information.

  In step S339, the system control unit 14 counts up the numerical value of the area where the main face switching count of the SDRAM 166 is recorded in order to continue the state where the display main face information does not exist for a predetermined period, and proceeds to step S340.

  In step S340, the system control unit 14 writes in the setting information held in the flash ROM 168 that the main face selection prohibition mode is set, and the process proceeds to step S333.

  In step S <b> 333, the system control unit 14 reads display face information from the SDRAM 166 and sends it to the display control unit 163. The display control unit 163 that has received the display face frame information superimposes the face frame data on the image data read out by the system control unit 14 and displays it on the display unit 164. The display face frame information input by the display control unit 163 is displayed. Of these, the display main face information is cleared. Since the display control unit 163 generates only the non-main face face frame without generating the main face face frame, as shown in FIG. 7B, the main face face frame does not exist and the non-main face face frame does not exist. Only the frame 401 is displayed.

  On the other hand, when the display main face is the same as the internal main face (S335), or the display main face has not disappeared (S336), or there is a main face switching instruction (S337), the system control unit 14 displays The face information is updated with the internal face information, and the process proceeds to step S333 (S341).

  Next, in step S342, the system control unit 14 reads out the main face switching count value from the SDRAM 166 and reads out the main face switching count threshold value from the flash ROM 168 for comparison. If the main face switching count value exceeds the main face switching count threshold, the process proceeds to step S345, and if not, the process proceeds to step S343. Here, it is assumed that the main face switching count threshold is 300. This means that assuming that the video camera 10 is operating at 30 frames per second and assuming that the process of FIG. 2 is executed once per frame, 10 seconds have elapsed.

  However, the present invention is not limited to this, and the threshold value to be compared with the main face switching count value can be set arbitrarily. In addition, the threshold may be set by the photographer.

  In step S343, it is determined whether a main face switching instruction is input from the photographer to the system control unit 14 via the operation unit 134. When the system control unit 14 receives a main face switching instruction, the process proceeds to step S345, and when the system control unit 14 does not receive a main face switching instruction, the process proceeds to step S344.

  In step S344, since the current display main face is disappearing, the system control unit 14 increments the main face switching count value of the SDRAM 166, and proceeds to step S333.

  On the other hand, in step S345, since the system control unit 14 receives a main face switching instruction from the photographer, the display face information is updated with the internal face information, and the process proceeds to step S346.

  After that, in step S333, the display main face information is still cleared, so that it is displayed on the display unit 164 as shown in FIG. In addition, when focusing on the main face frame, the AF detection unit 165 does not operate because there is no focus detection area to be focused.

  In step S346, the system control unit 14 clears the main face switching count in the SDRAM 166, and proceeds to step S347.

  In step S347, the system control unit 14 writes information to cancel the main face selection prohibition mode in the setting information of the flash ROM 168, and proceeds to step S333.

  When the above process is completed and the face frame drawing process is executed again in step S333, the display main face is present, and the display on the display unit 164 is as shown in FIG.

  By repeatedly executing the above processing, the face frame continues to be superimposed on the face portion of the subject of the image, and the main subject cannot be detected even when multiple subjects are detected while the AF mode is set only for the face. It is possible to prevent other subjects from switching to the main subject. This makes it possible to shoot video that is easy to edit.

  In the above description, the internal main face is determined in step S32, and it is determined whether or not the display face information is updated with the internal face information in step S33. It is also conceivable to perform processing separately in the mode and face priority AF mode. Hereinafter, another main face selection process will be described with reference to FIG.

  In the following description, only the processing different from the above description will be described. Therefore, in FIG. 12, the same reference numerals are given in the same case as the processing in FIG. 4 or FIG.

  If it is determined in step S331 in FIG. 9 that the face-only AF mode is not set, the previous internal main face has not disappeared in step S361 to be described later, or the main face selection prohibition mode is not set in step S334. Then, the process proceeds to step S323 in FIG.

  In step S361, the system control unit 14 reads the internal main face information from the SDRAM 166, compares the read internal main face information with the face information of the detection result, and compares the position and size of each face information, the face angle, and the face information. Compare feature differences. Specifically, it is assumed that the face is the same when the difference in face position (for example, the sum of the differences between the x coordinate and the y coordinate) is within the size of the previous internal main face. Further, it is assumed that the same face is obtained when the size of the face of the detection result is 1.5 times or less than the previous internal main face. Further, when the difference between the detected face angle and the previous internal main face angle is within 45 degrees, the face may be the same. Furthermore, it is also possible to digitize feature amounts such as the width of both eyes and the feature of the mouth position with respect to the position of the eyes, and when the difference between the values is within a predetermined amount, the same face can be obtained. Furthermore, when the sum of the numerical values obtained as described above is within a predetermined amount, it can be determined that the faces are the same.

  As a result of the comparison, if it is determined that the same face information as the previous internal main face exists in the detected face, it is determined that the previous internal main face has not disappeared, and the process proceeds to step S323. On the other hand, if it is determined that there is no face information identical to the previous internal main face in the detected face, it is determined that the previous internal main face has disappeared, and the process proceeds to step S334.

  The types of face frames are not limited to those shown in FIGS. 6 and 7 and may be any type of face frames. For example, consider a case where the main face frame 400 that existed in FIG. If the main face is switched internally when the main face frame 400 disappears, the candidate face that becomes the main face is displayed as the next main face frame 403 as shown in FIG. . Then, after a predetermined time has elapsed, the main face frame 400 is displayed as shown in FIG.

  The same type of face frame may be used in the face priority AF mode and the face-only AF mode, but the mode set to the photographer can be notified by expressing with different types of frames.

  [Embodiment 2] Next, the face frame display processing of Embodiment 2 will be described with reference to FIGS.

  In the first embodiment, when the main face disappears, only the non-main face frame is displayed without selecting the main face and displaying the main face frame until a predetermined time elapses. In contrast, in the second embodiment, panning or zooming operation of the video camera 10 is detected, and the main face frame is switched according to the detection result.

  FIG. 9 is a flowchart illustrating face frame display processing according to the second embodiment. In the flowchart of FIG. 9, the same processes as those in FIG.

  In steps S <b> 351 and S <b> 352, the system control unit 14 determines whether panning has been detected by the shake detection unit 17 or whether the photographer has performed a zoom operation via the operation unit 134. When a panning or zoom operation is detected, the process proceeds to steps S341 and S345. 10 and 11 illustrate screens displayed on the display unit 164 when the process proceeds to step S341 or S345.

  FIG. 10 shows an example in which panning is detected by the shake detection unit 17, and the panning is performed when the display main face disappears and the non-main face frames 401 and 402 are displayed as shown in FIG. Is detected. In this case, the system control unit 14 overwrites the display main face information with the internal main face information selected in step S327 of FIG. As a result, the display is displayed on the display unit 164 as shown in FIG. In addition, when the display main face frame 400 is present, the AF detection unit 165 notifies the system control unit of the fact that the AF detection unit 165 has detected that the degree of focus has decreased. The system control unit receives a notification from the AF detection unit 165 and instructs the focusing driving unit 133 to perform focusing, and the focusing driving unit 133 drives the focus lens 115.

  FIG. 11 shows an example in which a zoom operation by the photographer is detected. As shown in FIG. 11A, zooming is performed when the display main face disappears and the non-main face frames 401 and 402 are displayed. Suppose an operation is detected. In that case, the system control unit 14 overwrites the display main face information with the internal main face information selected in step S327 of FIG. As a result, the display is displayed on the display unit 164 as shown in FIG. Further, when the AF main detection unit 165 detects that the degree of focus has been reduced due to the presence of the display main face frame 400, the AF control unit 165 notifies the system control unit accordingly. The system control unit receives a notification from the AF detection unit 165 and instructs the focusing driving unit 133 to perform focusing, and the focusing driving unit 133 drives the focus lens 115.

  In each of the above-described embodiments, the case where a face is detected as a subject has been described. However, the present invention is not limited to face detection, and other than a face as long as a subject that satisfies a preset condition is detected. It can also be applied to other subjects.

  [Other Embodiments] The present invention is also realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads and executes the program code. It is processing to do. In this case, the program and the storage medium storing the program constitute the present invention.

  In addition, the present invention may be applied to a system including a plurality of devices (for example, a host computer, an interface device, a camera head, etc. constituting an image processing apparatus). Further, the present invention may be applied to an apparatus (for example, a digital still camera, a digital video camera, etc.) composed of one device.

Claims (10)

Imaging means for photoelectrically converting a subject image incident via a photographing optical system to generate an imaging signal;
Subject detection means for detecting a subject having a predetermined characteristic in a shooting screen from the imaging signal generated by the imaging means;
A setting for setting the first AF mode in which focus adjustment is performed by giving priority to the subject having the predetermined characteristic, and the second AF mode in which focus adjustment is performed only on the subject having the predetermined characteristic. Means,
A main subject that selects a main subject from the subjects detected by the subject detection means and newly selects a main subject from other subjects existing in the shooting screen when the main subject no longer exists in the shooting screen A selection means;
Focus detection means for detecting a focus state with respect to the main subject selected by the main subject selection means;
Focus adjusting means for executing a focus adjusting operation from the in-focus state detected by the focus detecting means;
In the second AF mode, when the main subject no longer exists in the shooting screen in a state where a plurality of subjects having the predetermined characteristics are detected, the case of the first AF mode imaging apparatus characterized by and a control means for prohibiting the selection of a new main object by the main object selecting means until after a long predetermined time than.   In the first AF mode, the control unit immediately detects the main subject when the main subject no longer exists in the shooting screen in a state where a plurality of subjects having the predetermined characteristics are detected. The imaging apparatus according to claim 1, wherein control is performed so that a new main subject is selected by the selection unit. An operation means for receiving a photographer's operation for selecting a main subject from the subjects detected by the subject detection means;
3. The image pickup apparatus according to claim 1, wherein when the main subject is selected by the operation unit, the control unit cancels prohibition of selection of a new main subject by the main subject selection unit. When the main subject no longer exists in the shooting screen, the control means reappears the same subject as the main subject that no longer exists in the shooting screen among the subjects detected by the subject detection means. Whether or not
The imaging apparatus according to claim 1, wherein when it is determined that the same subject has appeared, the prohibition of selection of a new main subject by the main subject selection unit is canceled.   The control means compares the main subject that no longer exists in the shooting screen with the size, position, or feature similarity of another subject, and the difference in size, position, or similarity is a predetermined value. The imaging apparatus according to claim 4, wherein when the difference is less than the difference, it is determined that the same subject as the main subject that no longer exists in the shooting screen appears again. It further comprises detection means for detecting zoom operation or panning of the imaging device,
When the zoom or panning of the imaging device is detected when the main subject is no longer present in the shooting screen and another subject is present, the control unit determines a new subject by the main subject selection unit. The imaging apparatus according to claim 1, wherein the prohibition of selection of the main subject is canceled. Frame display means for displaying a frame surrounding the subject in a superimposed manner on the subject image detected by the subject detection means;
7. The frame display unit according to claim 1, wherein the frame display unit displays different types of frames between the main subject selected by the main subject selection unit and another subject. Imaging device. A method for controlling an imaging apparatus having imaging means for photoelectrically converting a subject image incident through a photographing optical system to generate an imaging signal,
A subject detection step of detecting a subject having a predetermined characteristic in a shooting screen from the imaging signal generated by the imaging means;
A setting for setting the first AF mode in which focus adjustment is performed by giving priority to the subject having the predetermined characteristic, and the second AF mode in which focus adjustment is performed only on the subject having the predetermined characteristic. Process,
A main subject that selects a main subject from the subjects detected in the subject detection step and newly selects a main subject from other subjects existing in the shooting screen when the main subject no longer exists in the shooting screen A selection process;
A focus detection step for detecting a focus state with respect to the main subject selected by the main subject selection step;
A focus adjustment step of performing a focus adjustment operation from the in-focus state detected by the focus detection step;
In the second AF mode, when the main subject no longer exists in the shooting screen in a state where a plurality of subjects having the predetermined characteristics are detected, the case of the first AF mode control method characterized by and a control step of prohibiting the selection of a new main object by the main subject selecting step until after a long predetermined time than.   The program for functioning a computer as each means of the imaging device of any one of Claims 1 thru | or 7.   A computer-readable storage medium storing a program for causing a computer to function as each unit of the imaging apparatus according to claim 1.

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