JP2011018989A - Imaging device, image selection method, and program - Google Patents

Abstract

An object of the present invention is to not only reliably record an image considering a shutter time lag, but also to obtain the best image that also evaluates the state of a subject.
When a CPU 5 of a digital camera detects a full-press operation of a shutter button in a live view process (step S1) in which a solid-state image sensor 13 is continuously capturing images (step S2), this is detected. Accumulation of frame image data is started at the timing when the half-press operation is detected (step S6). Then, with respect to the reduced luminance image data of the accumulated frame image data, a specific frame image is selected from the plurality of accumulated frame image data in consideration of subject evaluation and time lag correction values by face detection, eye detection, and blink detection. Data is selected (step S9).
[Selection] Figure 3

Description

  The present invention relates to an imaging apparatus, an image selection method, and a program.

  Conventionally, in the case of shooting a subject by detecting the user's shutter button operation, there is a difference between the moment when the user recognizes the shutter opportunity and the time when the user recognizes the shutter opportunity and operates the shutter button. Since this occurs (this is called shutter time lag), there is an essential problem that it is easy to miss a photo opportunity.

  To solve this problem, continuous shooting is started by detecting half-pressing of the shutter button, and continuous shooting is continued at a long continuous shooting interval until a predetermined time has elapsed since the start of continuous shooting. There is known a digital camera that continues continuous shooting at a short continuous shooting interval after the elapse of time (see Patent Document 1). Also, the shutter time lag time is measured and continuous shooting is performed, and when the user presses the shutter button, a single picture taken at the time obtained by subtracting the shutter time lag time measured in advance from the time the shutter button is pressed is output. Thus, there is known a digital camera that can output one piece of a decisive moment (see Patent Document 2).

JP 2008-199476 A JP 2002-271673 A

  However, in the digital camera described in Patent Document 1, although there is a possibility that a decisive moment can be photographed, it is troublesome to select a single decisive moment image from among a large number of continuously shot images. There was a problem.

  The digital camera described in Patent Document 2 can record the best captured image from the viewpoint of capturing a photo opportunity, but the subject state in the captured image is not always the best, and as a result There is a possibility that the best image for the subject cannot be obtained.

  The present invention has been made in view of the above-described conventional problems, and is capable of not only reliably recording an image considering a shutter time lag but also obtaining the best image that also evaluates the state of a subject. For the purpose.

  An imaging apparatus according to a first aspect of the invention includes an imaging unit, a continuous imaging control unit that controls the imaging unit to continuously capture images, and a recording that detects a recording instruction of an image captured by the imaging unit. Based on the timing at which a recording instruction is detected by the recording instruction detecting means, an accumulating means for accumulating a plurality of image data picked up by the continuous imaging control means, and a plurality of data accumulated by the accumulating means Evaluation means for evaluating the imaging state of a subject included in the image data, a time lag correction value acquisition means for acquiring a time lag correction value, a time lag correction value acquired by the time lag correction value acquisition means, and an evaluation by the evaluation means And a selecting means for selecting specific image data from the plurality of image data stored by the storing means. Characterized in that was.

  An imaging apparatus according to a second aspect of the invention includes a face detection unit that detects a human face included in the subject from a plurality of image data stored by the storage unit, and a person detected by the face detection unit. Eye detection means for detecting eyes from the face of the person and blink detection means for detecting the degree of blinking of the eyes detected by the eye detection means, wherein the evaluation means is a blink detected by the blink detection means. Based on the degree, the imaging state of a person's face is evaluated as the imaging state of the subject.

  According to a third aspect of the present invention, in the imaging device, the storage unit includes a plurality of images before and after the timing when the recording instruction is detected by the recording instruction detection unit, at least before the timing, or after the timing. Data accumulation is started.

  According to a fourth aspect of the present invention, there is provided an image pickup apparatus further comprising display control means for controlling display of image data selected by the selection means.

  The image pickup apparatus according to a fifth aspect of the present invention further includes a recording unit that records the image data selected by the selection unit.

  An imaging method according to an embodiment of the present invention includes a continuous imaging control step for controlling an imaging unit to continuously capture images, and a recording instruction detection step for detecting a recording instruction for an image captured by the imaging unit. A storage step for storing a plurality of image data captured in the continuous imaging control step in a predetermined memory based on the timing at which the recording instruction is detected in the recording instruction detection step; An evaluation step for evaluating the imaging state of a subject included in a plurality of accumulated image data, a time lag correction value acquisition step for acquiring a time lag correction value, a time lag correction value acquired in the time lag correction value acquisition step, and the Based on the evaluation in the evaluation step, a specific image data is selected from the plurality of image data stored in the storage step. Characterized in that it comprises a selection step of selecting the data, the.

According to a seventh aspect of the present invention, there is provided an imaging program comprising: a computer included in the imaging device;
Based on the timing at which the recording instruction is detected by the recording instruction detecting means, the recording instruction detecting means for detecting the recording instruction of the image to be picked up, and the continuous imaging control means by the continuous imaging control means. Storage means for storing a plurality of captured image data in a predetermined memory, evaluation means for evaluating an imaging state of a subject included in the plurality of image data stored by the storage means, and a time lag correction value for acquiring a time lag correction value Selection means for selecting specific image data from a plurality of image data stored by the storage means based on the acquisition means, the time lag correction value acquired by the time lag correction value acquisition means and the evaluation by the evaluation means; It is made to function as.

  According to the present invention, it is possible not only to reliably capture a photo opportunity image in consideration of the shutter time lag but also to evaluate the state of the subject and obtain the best image for the subject.

1 is a block diagram of a digital camera according to an embodiment of the present invention. It is a flowchart explaining the time lag correction process which concerns on embodiment of this invention. It is a flowchart explaining the selection process which concerns on embodiment of this invention. It is a flowchart explaining the time lag correction measurement process which concerns on embodiment of this invention. It is a figure explaining the time lag correction measurement process which concerns on embodiment of this invention. It is a figure explaining the time lag correction measurement process which concerns on embodiment of this invention. It is a figure explaining the time lag correction measurement process which concerns on embodiment of this invention. It is a figure explaining the selection process which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a digital camera 1 according to an embodiment of the present invention. The digital camera 1 includes an imaging system 2, a memory card 3, a bus 4, a CPU (Central Processing Unit) 5, a RAM (Random Access Memory) 6, an image display unit 7, a ROM (Read Only Memory) 8, and a key input unit 9. A plurality of frame image data obtained by continuously capturing images at a predetermined frame rate (for example, 1000 fps) in the imaging system 2 and temporarily acquired in the RAM 6.

  The imaging system 2 includes a lens driving block 10, a lens 11, a diaphragm 12, a solid-state imaging device 13, a driver 14, a timing generator (TG) 15, a signal processing unit 16, and the like.

  The lens driving block 10 changes the focus, magnification, and aperture 12 of the lens 11 under the control of the CPU 5 via the bus 4. The lens 11 condenses incident light on the imaging surface of the solid-state imaging device 13 via the diaphragm 12 and forms an optical image of the subject on the imaging surface of the solid-state imaging device 13.

  The solid-state imaging device 13 may be an imaging device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor). The solid-state image sensor 13 operates in accordance with various drive signals output from the driver 14 and outputs an image of an optical image formed on the imaging surface as an image signal. The CPU 5 controls the frame rate, charge accumulation time, and the like that are imaged by the solid-state imaging device 13. In the imaging system 2, the driver 14 generates a driving signal for the solid-state imaging device 13 in accordance with various timing signals output from the timing generator 15. The CPU 5 controls the timing generator 15 via the bus 4. Therefore, the timing signal output to the driver 14 is also controlled by the CPU 5.

  The signal processing unit 16 performs correlated double sampling processing (CDS: Correlated Double Sampling) on the imaging signal output from the solid-state imaging device 13, and then performs automatic gain adjustment (AGC: Automatic Gain Control), analog-digital conversion processing (AD: Analog to Digital converter) and outputs the captured frame image data to the bus 4.

  The RAM 6 is used as a buffer memory for temporarily storing frame image data sent by the CPU 5 after being imaged by the solid-state imaging device 13, and temporarily stores data processed by the detection unit 17 and the CPU 5. Used as working memory.

  The detection unit 17 includes a face detection unit 18, an eye detection unit 19, and a blink detection unit 20. The detection unit 17 also has a function of detecting a subject from reduced luminance image data of a plurality of frame image data.

  The face detection unit 18 detects a human face from a reduced luminance image data of each of a plurality of frame image data constituting the image data using a predetermined face detection method. Specifically, the face detection unit 18 detects a face image area from each frame image data based on the reduced luminance image data temporarily stored in the RAM 6, and the image information in the detected face image area is detected as a face. Generate as frame information. Since the face detection process is a known technique, detailed description thereof is omitted here.

  For frame image data in which no face has been detected by the face detection unit 18, frame image data in which face detection has not been performed based on the coordinates of the face image area most recently detected from the previous and subsequent frame image data. To set face frame information. In other words, since continuous shooting has an extremely short imaging interval, when a face is detected from any one of the frame image data, there is a human face in the frame image data before and after that. Face frame information even in frame image data in which no face is detected using the coordinates of the face image area of the frame image data in which the face is detected (for example, the coordinates of the four corners of the rectangular frame). Set.

  The eye detection unit 19 detects the eyes of a human face based on the face frame information of each frame image data generated by the face detection unit 18. Specifically, the eye detection unit 19 detects the left and right eyes of all persons in each frame image data based on the face frame information of each frame image data, and calculates the center coordinates thereof. Since the eye detection process is a known technique, detailed description thereof is omitted here.

  Further, the eye detection unit 19 includes a reliability calculation unit 19a and an effectiveness determination unit 19b. The reliability calculation unit 19 a calculates the detection reliability related to the eye detection by the eye detection unit 19. Specifically, the reliability calculation unit 19a calculates the detection reliability adjusted to decrease the reliability when, for example, the face detection frame is inappropriate or the face is facing sideways. .

  The validity determination unit 19b determines the validity of the face from which the eye related to the reliability is detected according to whether or not the detection reliability calculated by the reliability calculation unit 19a is equal to or less than a predetermined threshold. Then, when the detection reliability is equal to or less than a predetermined threshold, the effectiveness determination unit 19b determines that the face related to the eye detection is NG determination and sets the face for which the eye detection is not effective, thereby a blink detection unit described later It is not used in blink detection at 20. On the other hand, when the detection reliability is greater than a predetermined threshold, the effectiveness determination unit 19b determines that the face related to the eye detection is OK and sets the face for which eye detection is effective, thereby detecting subsequent blink detection. This is used for blink detection in the unit 20.

  The blink detection unit 20 detects the degree of eye blink detected by the eye detection unit 19. Specifically, the blink detection unit 20 has the coordinates of the left and right eyes of the human face determined to be valid by the validity determination unit 19b for the reduced luminance image data of all the frame image data generated by continuous shooting. Based on the information, the degree of eye blink in the reduced luminance image is searched, and the blink evaluation value is calculated according to the degree of eye blink. The blink evaluation value represents that the larger the value, the more open the eyes. Here, the blink detection unit 20 constitutes a blink detection unit that detects the degree of blinking of the eyes detected by the eye detection unit 19.

  The image display unit 7 is a display unit configured by a liquid crystal display panel or the like, and acquires and displays frame image data from the memory card 3 via the bus 4 under the control of the CPU 5 during reproduction. Similarly, the image display unit 7 acquires and displays frame image data from the RAM 6 via the bus 4 under the control of the CPU 5 during imaging.

  The CPU 5 is a controller that controls the operation of the digital camera 1 according to the present embodiment. The CPU 5 executes a program stored in the ROM 8 and responds to a user operation detected by the key input unit 9 to perform the present embodiment. The operation of each part of the digital camera 1 is controlled.

  In the present embodiment, a program in which the following processing executed by the CPU 5 is described is described as being stored in advance in the ROM 8 and provided. However, the present invention is not limited to this. For example, the program may be recorded on a recording medium such as a memory card and provided, or may be provided by downloading via a network.

  The key input unit 9 includes a plurality of operation keys such as a shutter button that can be fully pressed halfway, a power on / off key, a mode switching key, a cross key, and a SET key, and outputs an operation signal according to a user key operation to the CPU 5. To do.

  When the CPU 5 receives an instruction to reproduce the frame image data recorded on the memory card 3 from the user, the CPU 5 sequentially acquires the corresponding frame image data from the memory card 3, decompresses this image data, and stores it in the RAM 6. . Further, the CPU 5 sequentially transfers the frame image data from the RAM 6 to the image display unit 7 and causes the image display unit 7 to display the frame image data. Thus, the CPU 5 reproduces a still image from the frame image data recorded on the memory card 3 and causes the image display unit 7 to display it.

  When receiving a shooting instruction from the user, the CPU 5 sequentially stores the frame image data acquired by controlling the imaging system 2 in the memory card 3. Further, the CPU 5 executes gamma correction processing, demosaic processing, white balance processing, etc. on the frame image data and stores them again in the memory card 3, and sequentially displays the series of the frame image data thus stored. It is transferred to the part 7 and displayed.

<Time lag correction processing>
FIG. 2 is a flowchart showing a processing procedure of the CPU 5 according to the time lag correction processing according to the embodiment of the present invention. When the still image shooting mode is set by the user operating the mode switching key of the key input unit 9, the CPU 5 starts imaging with the solid-state imaging device 13 at a predetermined frame rate (for example, 1000 fps). The frame image data sequentially captured by the solid-state imaging device 13 and output from the signal processing unit 16 is stored in the RAM 6, and an image corresponding to the stored frame image data is displayed on the image display unit 7. The live view process for displaying is started (step S1).

  Next, the CPU 5 determines whether or not a user has pressed a key such as a shutter button (step S2). When the CPU 5 determines that the key is not pressed, the CPU 5 returns to step S1 and waits for the live view process of step S1 until the key is pressed. When determining that the key has been pressed, the CPU 5 determines whether or not a half-pressing operation of the shutter button by the user has been detected (step S3). This determination is made based on whether or not an operation signal corresponding to a half-press operation of the shutter button has been sent from the key input unit 9. At this time, when the user thinks that a photo opportunity will come soon, a half-press operation of the shutter button is performed.

  When the CPU 5 determines that the half-pressing operation of the shutter button by the user has been detected, the CPU 5 performs other processing (step S4). Other processing includes frame rate (continuous shooting speed) change, shooting scene change processing, and the like.

  At this time, when the user operates the frame rate setting key and an operation signal corresponding to the operation of the frame rate setting key is sent from the key input unit 9, the CPU 5 sets the current frame rate to the set frame rate. change. Examples of the frame rate type include 15 fps, 30 fps, 60 fps, and 1000 fps. At this time, when the shooting scene setting key is operated by the user and an operation signal corresponding to the shooting scene setting key is sent from the key input unit 9, the CPU 5 changes the current shooting scene to the set shooting scene. change. When the user wants to shoot a subject under the shooting conditions of the shooting scene most suitable for the current subject situation, the shooting conditions can be changed by operating the shooting scene setting mode key. This shooting scene includes a plurality of shooting scenes such as “photographing a person”, “photographing a landscape”, “photographing a child”, “photographing sports”, etc., and the shooting conditions corresponding to each of the shooting scenes are also recorded. ing. When the CPU 5 determines that the half-press operation has been detected, the CPU 5 performs focus processing and exposure measurement processing (step S5). At this time, when the movement of the subject is determined by the CPU 5, it is determined that the subject is predicted, and when the movement of the subject is not determined, it is determined that the subject cannot be predicted.

  Next, the CPU 5 starts accumulating frame image data taking into account a time lag correction value described later (step S6). The time lag correction value is a predetermined time value (period) from when the user visually recognizes the measurement subject 101 to when the shutter button is fully pressed. By acquiring this time lag correction value in advance, the user's shutter time lag can be corrected. When the movement of the subject is determined in step S5, the time lag correction value starts to accumulate frame image data in consideration of the time lag correction value of the shooting situation in which the movement of the subject is predicted. If no determination is made, accumulation of frame image data is started in consideration of a time lag correction value in a shooting situation in which the movement of the subject cannot be predicted. This accumulation process sequentially accumulates the captured frame image data until there is no free space in the RAM 6 serving as a buffer memory. When there is no free space in the buffer memory, the newly captured frame image data is stored in the buffer memory. Is to overwrite the oldest frame image data among the plurality of frame image data stored in. This accumulation process is continuously performed until the release of the shutter button is detected or a full press operation of the shutter button is detected. As a result, the frame image data from the most recently captured frame image data to a certain time before is accumulated. At this time, the corresponding reduced luminance image data is sequentially generated together with the frame image data, stored in the buffer memory sequentially, and accumulated, and when the buffer memory runs out of space, the newly generated reduced luminance image data is Overwriting the oldest reduced luminance image data among the plurality of reduced luminance image data stored in the buffer memory.

  Next, the CPU 5 determines whether or not the shutter button has been released (the user has released his / her hand) (step S7). When it is determined that the shutter button has been released, the accumulation process in step S6 is terminated, and the process returns to the live view process in step S1. On the other hand, when it is determined that the shutter button has not been released, it is determined whether or not a full press operation (recording instruction) of the shutter button by the user has been detected (step S8).

  When the CPU 5 determines that the shutter button full-pressing operation has not been detected, the CPU 5 returns to step S5 and repeats the processes of steps S5 to S8 until the shutter button full-pressing operation is detected.

  On the other hand, when the CPU 5 determines that the full pressing operation of the shutter button is detected, the CPU 5 performs a selection process described with reference to FIG. 3 described later (step S9). In this selection process, the best image is obtained from a plurality of reduced luminance image data near the time lag correction value based on the time lag correction value measured in the time lag correction measurement process described with reference to FIG. As described above, a process of selecting frame image data corresponding to the reduced luminance image data in which the subject's eyes are not obstructed is performed. When this process ends, the time lag correction process ends.

<Selection process>
FIG. 3 is a flowchart illustrating a processing procedure of the CPU 5 according to the selection processing according to the embodiment of this invention. First, the CPU 5 causes the face detection unit 18 to detect a human face from the reduced luminance image data of each frame image data using a predetermined face detection method, and the image information in the detected face image area is used as face information. Generate (step S11).

  Next, the CPU 5 causes the eye detection unit 19 to detect both the left and right eyes of the person based on the face frame information generated by the face detection unit 18, calculates the center coordinates thereof, and the reliability of the eye detection unit 19. The degree calculation unit 19a is made to calculate the detection reliability related to the eye detection (step S12).

  Next, the CPU 5 causes the validity determination unit 19b of the eye detection unit 19 to check whether the eye related to the reliability depends on whether the detection reliability calculated by the reliability calculation unit 19a is equal to or less than a predetermined threshold. The effectiveness of the detected face is determined (step S13). Specifically, when the detection reliability is equal to or less than a predetermined threshold, the validity determination unit 19b determines that the face related to the eye detection is NG determination and sets the face for which the eye detection is not effective, while detecting reliability When the degree is larger than a predetermined threshold, the face related to the eye detection is determined to be OK, and the face is determined to be valid when the eye detection is effective.

  Next, the CPU 5 searches for the degree of blinking in the reduced luminance image data based on the coordinate information of the left and right eyes of the face of the person determined to be OK by the validity determination unit 19b, and the degree of blinking of the eye The blink evaluation value is calculated according to (Step S14).

  Next, the CPU 5 selects target frame image data from the frame image data near the time lag correction value based on the blink evaluation value (step S15). In this process, a process of selecting frame image data having a large blink evaluation value calculated in step S14 from a plurality of frame image data determined based on the time lag correction value is performed. Specifically, it will be described later with reference to FIG.

  Next, the CPU 5 records the frame image data selected in step S15 on the memory card 3 (step S16). Next, the CPU 5 displays the selected frame image data on the image display unit 7 (step S17). When this process ends, the selection process ends.

<Time lag correction measurement processing>
FIG. 4 is a flowchart showing a processing procedure of the CPU 5 according to the time lag correction measurement processing according to the embodiment of the present invention. CPU5 will start a time lag correction measurement process, if a time lag correction measurement mode is set by operation of the mode switching key of a user's key input part 9. FIG. First, the CPU 5 performs measurement counter initialization processing (step S21). In this process, the measurement counter stored in the RAM 6 is initialized to 0, and a plurality of values corresponding to the number of times the time lag correction value is measured are set in the measurement counter. In the present embodiment, in order to measure the time lag correction value three times, a process of setting 3 to the measurement counter is performed.

  Next, the CPU 5 determines whether or not the shutter button or the like has been operated by the user (step S22). When the CPU 5 determines that it has not been operated, it returns to step S21 and waits for the measurement counter initialization process of step S21 until it is operated. On the other hand, when determining that the operation has been performed, the CPU 5 further determines whether or not a half-press operation of the shutter button has been detected (step S23). That is, when the user is ready to measure the time lag correction value, the shutter button is half-pressed.

  When the CPU 5 determines that the above operation is not a half-press operation of the shutter button, the CPU 5 performs other corresponding processing (step S24). The “other corresponding processes” include a frame rate change and a shooting scene change process. On the other hand, when determining that the half-press operation has been detected, the CPU 5 determines whether or not the shutter button has been released (the user has released his / her hand from the shutter button) (step S25). When the CPU 5 determines that the shutter button has been released, the CPU 5 returns to step S22 and again waits for key operation detection.

  On the other hand, when determining that the shutter button is not released, the CPU 5 starts measuring the time lag correction value (step S26). Specifically, when 3 is set in the measurement counter, that is, when the first time lag correction value is measured, as shown in FIG. 5, nothing is displayed on the image display unit 7 first. The measurement subject 101 is displayed from the state (state of FIG. 5A) (state of FIG. 5B), and measurement of the time lag correction value is started. The measurement result obtained by measuring the first time lag correction value is measured as a time lag correction value in a shooting situation in which the movement of the subject cannot be predicted.

  When 2 is set in the measurement counter, that is, in the case of measuring the second time lag correction value, first, the measurement subject 101 freely moves on the image display unit 7 as shown in FIG. After a predetermined time has elapsed since the display (state C in FIG. 6), the measurement subject 101 is displayed in a rectangular frame 102 provided substantially at the center of the image display unit 7 (D in FIG. 6). State) and start measuring the time lag correction value. In the second measurement of the time lag correction value, it is determined whether or not the shutter button has been fully pressed at the timing when the measurement subject 101 is displayed in the rectangular frame 102. The measurement result obtained by measuring the second time lag correction value is measured as a time lag correction value in a shooting situation in which the movement of the subject cannot be predicted.

  Further, when 1 is set in the measurement counter, that is, in the case of the third time lag correction value measurement, as shown in FIG. Displayed to move with a certain rule (state E in FIG. 7), and after a predetermined time has elapsed, the measurement subject 101 is displayed in a rectangular frame 102 provided substantially at the center of the image display unit 7. (The state of F in FIG. 7) and the measurement of the time lag correction value is started. In the third measurement of the time lag correction value, it is determined whether or not the shutter button has been fully pressed at the timing when the measurement subject 101 is displayed in the rectangular frame 102. The measurement result obtained by measuring the third time lag correction value is measured as a time lag correction value in a shooting situation in which the movement of the subject can be predicted.

  Next, the CPU 5 determines whether or not a full press operation of the shutter button has been detected by the above determination (step S27). At this time, when the user determines that the measurement subject is displayed on the image display unit 7, the user fully presses the shutter button.

  When the CPU 5 determines that the full-press operation has not been detected, the CPU 5 returns to step S25 and repeats the processes of steps S25 to S27 until the full-press operation is detected. On the other hand, when it is determined that the full-press operation has been detected, the CPU 5 performs a measurement process (step S28). In this process, in the process of step S26, a process of measuring the time lag correction value in advance and measuring in advance the time from the user's visual recognition to pressing the shutter button as the time lag correction value is performed. This process is performed a plurality of times according to the remaining number of measurement counters. When this measurement process ends, the CPU 5 performs a process of subtracting 1 from the measurement counter.

  Next, the CPU 5 determines whether or not the measurement counter is 0 as a result of subtracting 1 from the measurement counter (step S29). When the CPU 5 determines that the remaining measurement counter is not zero, the CPU 5 returns to step S22 and measures the second time lag correction value or the third time lag correction value according to the remaining number of the measurement counter.

  On the other hand, when the CPU 5 determines that the measurement counter is 0 as a result of subtracting 1 from the measurement counter, the CPU 5 performs a measurement aggregation process (step S30). In this process, data corresponding to the number of measurement counters is measured, and the shooting situation in which the movement of the subject is predicted (measurement results of the first and second time lag correction values) and the shooting situation that cannot be predicted (third time lag correction value). And the average value of the data. If the movement of the subject can be monitored within the time lag correction process, use the average value of the time lag correction value in the shooting situation where the movement of the subject can be predicted, and if the movement of the subject cannot be monitored within the time lag correction process By using the average value of the time lag correction value in a shooting situation in which the movement of the subject cannot be predicted, the accuracy of the time lag correction value can be further increased. When this process ends, the time lag correction measurement process ends.

Next, the selection process in the present embodiment will be described in detail with reference to FIG. When performing the detection photographing preparing a half-press operation of the shutter button by the user, 1000 fps frame rate, i.e., the frame image data in one frame rate of 0.001 seconds accumulation is started at time t ₁ . The plurality of accumulated frame image data are sequentially stored in the RAM 6 and accumulated.

When the time lag correction value obtained in advance is 0.01 seconds at the time t ₂ when the full pressing operation of the shutter button is detected, the time lag correction value from the time t ₂ is 0.01 seconds. The retroactive frame image data is temporarily determined. In this embodiment, consists of the time t ₂ and time lag correction frame image data a back 10 frames, which corresponds to 0.01 seconds which is the consideration of only the time lag correction value (0.01 seconds) frame image data .

Then, 10 frames before and after (b in FIG. 8) including the frame image data a taking into account only the time lag correction value are acquired. Then, frame image data c having a large blink evaluation value is selected from the 10 frames based on the reduced luminance image data of each frame image data. In the present embodiment, the estimated blink value of the frame image data c is, is greater than the estimated blink value of the frame image data a, the user of the previous 10 frames back from the time t ₂ fully pressed the shutter button frame image in data a no, the frame image data c of the previous 6 frames back from the time t ₂ is selected.

  Therefore, in the present embodiment, the time lag correction value is measured in advance, and the frame image data accumulation process is performed retroactively from the time including the time lag correction value, so that an image in consideration of the shutter time lag can be reliably recorded. In addition, it is possible to obtain the best image in consideration of the state of the subject.

  In addition, by storing the selected single image in the memory card 3, it is possible to select the frame image data in which the decisive moment is photographed more reliably than when the user manually selects from a large amount of frame image data. Can do.

  Further, by displaying the selected one on the image display unit 7, it is possible to display the frame image data in which the decisive moment is captured more reliably than displaying a large amount of frame image data.

  The digital camera 1 according to various embodiments has been described above. In the present embodiment, the time lag correction value obtained by dividing the time lag correction values for the case where the motion of the subject is predicted and the case where the movement cannot be predicted is averaged is used, but the present invention is not limited to this. For example, a plurality of time lag correction values may be aggregated into one and used as an average value as time lag correction values in all shooting states.

  Further, in the present embodiment, the selection process is performed according to the blinking degree of the person of the subject detected by the blink detection unit 20, but the present invention is not limited to this. For example, the selection process may be performed according to the smile level of the face detected by the eye detection unit 19. Specifically, the configuration of the digital camera 1 includes a smile detection unit. Then, based on the position information of the eyes detected by the eye detection unit 19, the smile detection unit detects the smile level at which the eyes are detected. The smile detection unit reduces the reduced luminance image data of all the frame image data generated by the continuous shooting based on the coordinate information of the left and right eyes of the human face determined to be valid by the validity determination unit 19b. One of the mouths is searched in the luminance image, and a smile value is calculated according to the degree to which the mouth corner is raised. The frame image data having the largest smile value calculated in this way may be selected from among a plurality of frame image data as the best frame image data.

  Further, in the present embodiment, the selection process is performed according to the blinking degree of the person of the subject detected by the blink detection unit 20, but the present invention is not limited to this. For example, among the reduced luminance image data of the accumulated frame image data, for each of the reduced luminance image data for which the face is determined to be effective by the validity determination unit 19b, a selection process is performed based on the amount of blur between adjacent ones. You may go. Specifically, the configuration of the digital camera 1 includes a shake detection unit. The blur detection unit detects a blur evaluation value (blur amount) between adjacent ones of the reduced luminance image data of the plurality of frame image data generated by continuous shooting. The blur detection unit detects a human face from the reduced luminance image data of a plurality of frame image data generated by continuous shooting when a human face is not detected in the face detection process, or from one of the reduced luminance image data. When the number of faces that are detected but for which eye detection is effective is 0, each reduced luminance image data (or each frame image data) is divided into predetermined areas, and adjacent ones in each block. The difference between the blocks at the same position is calculated, and the largest difference value among all the blocks is calculated as the blur evaluation value. The image having the smallest blur evaluation value calculated in this way may be selected from a plurality of frame image data.

1 Digital Camera 2 Imaging System 3 Memory Card 4 Bus 5 CPU
6 RAM
7 Image display 8 ROM
DESCRIPTION OF SYMBOLS 9 Key input part 10 Lens drive block 11 Lens 12 Aperture 13 Solid-state image sensor 14 Driver 15 Timing generator 16 Signal processing part 17 Detection part 18 Face detection part 19 Eye detection part 19a Reliability calculation part 19b Effectiveness determination part 20 Blink detection part

Claims (7)

Imaging means;
Continuous imaging control means for controlling the imaging means to continuously capture images;
Recording instruction detecting means for detecting a recording instruction of an image captured by the imaging means;
A storage unit that stores a plurality of image data captured by the continuous imaging control unit based on a timing at which a recording instruction is detected by the recording instruction detection unit;
Evaluation means for evaluating the imaging state of the subject included in the plurality of image data accumulated by the accumulation means;
Time lag correction value acquisition means for acquiring a time lag correction value;
Based on the time lag correction value acquired by the time lag correction value acquisition means and the evaluation by the evaluation means, a selection means for selecting specific image data from the plurality of image data stored by the storage means;
An imaging apparatus comprising: Face detection means for detecting a human face included in the subject from a plurality of image data stored by the storage means;
Eye detection means for detecting eyes from a human face detected by the face detection means;
Blink detection means for detecting the blink degree of eyes detected by the eye detection means;
Further comprising
The imaging apparatus according to claim 1, wherein the evaluation unit evaluates an imaging state of a human face as an imaging state of the subject based on a blink degree detected by the blink detection unit. The storage means includes
The accumulation of a plurality of image data is started at least before, before, or after the timing when the recording instruction is detected by the recording instruction detecting unit. Imaging device.   The imaging apparatus according to claim 1, further comprising display control means for controlling display of image data selected by the selection means.   5. The imaging apparatus according to claim 1, further comprising a recording unit that records the image data selected by the selection unit. A continuous imaging control step for controlling the imaging unit to continuously capture images;
A recording instruction detection step of detecting a recording instruction of an image captured by the imaging unit;
An accumulation step for accumulating a plurality of image data captured in the continuous imaging control step in a predetermined memory based on the timing at which the recording instruction is detected in the recording instruction detection step;
An evaluation step for evaluating the imaging state of the subject included in the plurality of image data accumulated in the accumulation step;
A time lag correction value acquisition step for acquiring a time lag correction value;
Based on the time lag correction value acquired in the time lag correction value acquisition step and the evaluation in the evaluation step, a selection step of selecting specific image data from the plurality of image data stored in the storage step;
An image selection method comprising: A computer provided in the imaging apparatus;
Continuous imaging control means for controlling continuous imaging;
Recording instruction detection means for detecting a recording instruction of an image to be captured;
A storage unit that stores, in a predetermined memory, a plurality of pieces of image data captured by the continuous imaging control unit based on a timing at which a recording command is detected by the recording command detection unit;
Evaluation means for evaluating the imaging state of the subject included in the plurality of image data stored by the storage means;
Time lag correction value acquisition means for acquiring a time lag correction value;
A selection unit that selects specific image data from a plurality of image data stored by the storage unit based on the time lag correction value acquired by the time lag correction value acquisition unit and the evaluation by the evaluation unit;
A program characterized by functioning as

Images