JP5434104B2 - Electronic camera - Google Patents

Description

  The present invention relates to an electronic camera having a face detection function.

  Conventionally, an electronic camera that determines the degree of smile of a person is known (see, for example, Patent Document 1).

  However, in the electronic camera disclosed in Patent Document 1, if the subject is a smile, photographing may be performed regardless of the composition. Therefore, even if the subject is a smile, there is room for improvement in that the subject is not always photographed with a preferable composition.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an electronic camera that allows shooting with a preferred composition when a subject has a specific facial expression.

According to one aspect, the electronic camera captures a subject and generates image data, a display unit that displays an image based on the image data, and a through image that is a moving image acquired for composition confirmation In contrast, a first mark display control unit that superimposes and displays a first mark for determining the composition of still image shooting at a specific position of the through image, and for moving the first mark from the specific position to an arbitrary position. An operation unit for inputting the position of the movement destination, a face detection unit for detecting a face region from the through image, and a second mark indicating the face region on the through image based on the detection result of the face detection unit are superimposed and displayed. A second mark display control unit, a face recognition unit that extracts a facial feature value, a facial expression determination unit that determines a facial expression based on the feature value, an arbitrary position where the first mark is displayed, and a second The distance from the place where the placemark is displayed is set in advance. A position determination unit that determines whether the threshold has been reached, and an imaging unit when the position determination unit determines that the distance has reached the threshold and the facial expression corresponding to the second mark is a specific facial expression And a shooting control unit that performs still image shooting.

  According to the electronic camera of the present invention, it is possible to perform photographing with a preferable composition when the subject has a specific facial expression.

1 is a block diagram illustrating a configuration of an electronic camera 1 according to a first embodiment. Front view and rear view of electronic camera 1 Flow chart showing photographing operation of electronic camera 1 Diagram explaining setting of placemark The figure explaining the outline of the processing from when the face area is detected until shooting is performed Illustration explaining the reflection of a finger The figure explaining the 1st modification The figure explaining the 2nd modification The block diagram which shows the structure of the electronic camera 1 of 2nd Embodiment. The flowchart showing the imaging | photography operation | movement of the electronic camera 1 of 2nd Embodiment. A figure explaining an example of photography operation in electronic camera 1 of a 2nd embodiment. A figure explaining an example of photography operation in electronic camera 1 of a 2nd embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the “smile / composition mode (smile / framing mode)” described in the first embodiment is a pre-set composition (preferred composition) and the subject's face has a specific facial expression (smile). In this mode, it is determined that the electronic camera performs shooting (details will be described later).

  FIG. 1 is a block diagram illustrating a configuration of an electronic camera 1 according to the first embodiment. As shown in FIG. 1, the electronic camera 1 includes a photographing lens 10, an imaging unit 11, an image processing unit 12, a RAM (Random Access Memory) 13, a ROM (Read Only Memory) 14, an operation unit 15, Release button 16, touch panel 17, CPU (Central Processing Unit) 18, display monitor 19, recording interface (recording I / F) 20, recording medium 21, light receiving sensor 22, attitude detection sensor 23, And a bus 24. Among these, the image processing unit 12, the RAM 13, the ROM 14, the CPU 18, the display monitor 19, and the recording interface (recording I / F) 20 are connected to each other via a bus 24. The operation unit 15, the release button 16, the touch panel 17, the light receiving sensor 22, and the posture detection sensor 23 are connected to the CPU 18.

  The photographing lens 10 includes a plurality of lens groups including a zoom lens and a focus lens. For the sake of simplicity, FIG. 1 shows the photographic lens 10 as a single lens.

  The imaging unit 11 includes a lens driving mechanism, a diaphragm, a shutter mechanism, an imaging device, a timing generator, an AFE (analog front end), and the like. The imaging unit 11 photoelectrically converts the subject image formed by the photographic lens 10 to generate image data. Note that the imaging unit 11 outputs image data of a recording still image at the time of shooting. Further, the imaging unit 11 outputs image data of a through image that is a moving image for composition confirmation every time a predetermined time elapses during standby for shooting.

  Image data output by the imaging unit 11 is temporarily recorded in the RAM 13. This RAM 13 also functions as a frame memory.

  The image processing unit 12 reads one frame of image data recorded in the RAM 13 and performs various image processing (gradation conversion processing, contour enhancement processing, white balance processing, etc.).

  The ROM 14 is a non-volatile memory that stores a program for controlling the electronic camera 1 in advance.

  The operation unit 15 receives an instruction input such as each operation key described later and issues a processing instruction to the CPU 18.

  The release button 16 is a half-press operation (automatic exposure (AE) before shooting, AE: auto focus operation start) instruction input and full-press operation (imaging operation start) instruction Accept input. In the smile / composition mode, upon receiving an instruction input for a half-press operation and a subsequent full-press operation, the CPU 18 determines that it is a shooting timing if the determination result of the facial expression determination unit 18 described later is a smile. Switch to the setting that allows you to shoot. Note that an imaging control unit 18g, which will be described later, performs control of “determining that it is an imaging timing and performing imaging”. In the present embodiment, this control may be referred to as “automatic imaging”.

  In the smile / composition mode, even if a half-press operation is performed, an instruction to start an operation such as automatic focusing (AF) is not input, and automatic focusing (AF) or the like is performed according to an instruction from the imaging control unit 18g described later. Done.

  The display monitor 19 displays a still image, a through image, an operation menu of the electronic camera 1, and the like. Further, the display monitor 19 displays the first mark and the second mark on the through image. Here, the first mark is a mark for composition confirmation, and is simply referred to as “mark” hereinafter. The second mark is a mark indicating a face area in the through image, and is, for example, a detection frame surrounding the face area. Hereinafter, the second mark is referred to as “detection frame”. As the display monitor 19, a liquid crystal monitor or the like can be appropriately selected and used.

  The touch panel 17 detects the position of a fingertip or the like that touches the touch panel surface. The touch panel 17 receives the input from the photographer by outputting the detected position information to the CPU 18.

  The touch panel 17 is composed of a transparent panel having a size equivalent to that of the display monitor 19, and is stacked on the entire surface of the display monitor 19. Moreover, in the example of this embodiment, the touch panel 17 is comprised with the electrostatic capacitance type panel which senses the electrical signal by static electricity. The configuration of the touch panel 17 is not limited to the capacitance type, and a resistive film type panel that detects a change in voltage due to pressure may be used.

  A connector for connecting a recording medium 21 is formed in the recording interface (recording I / F) 20. The recording interface (recording I / F) 20 accesses the recording medium 21 connected to the connector according to an instruction from the CPU 18 and performs image recording processing.

  The light receiving sensor 22 is a light receiving element that converts light into an electrical signal. The light receiving sensor 22 is used to detect the reflection of the photographer's finger. The posture detection sensor 23 is a posture sensor that detects a rotational position (posture) around the optical axis of the electronic camera 1. The posture detection sensor 23 is used to detect a so-called vertical position and horizontal position of the electronic camera 1. Note that the process of detecting the attitude of the electronic camera 1 can be realized by using a known technique.

  The CPU 18 is a processor that controls the electronic camera 1. The CPU 18 controls each part of the electronic camera 1 by executing a sequence program stored in advance in the ROM 14. In addition, the CPU 18 of this embodiment includes a landmark display control unit 18a, a face detection unit 18b, a detection frame display control unit 18c, a position determination unit 18d, a face recognition unit 18e, an expression determination unit 18f, and an expression determination. It also functions as the unit 18g and the notification unit 18h.

  When the smile / composition mode is set, the mark display control unit 18a superimposes and displays a mark for determining a still image shooting composition on a specific position on a through image that is a moving image acquired for composition confirmation. This specific position is, for example, the center position of the through image. Alternatively, the mark display control unit 18a accepts an instruction input from the operation unit 15 or the touch panel 17, and arranges the mark at a specified position on the through image. Alternatively, the mark display control unit 18a places a mark on the selected intersection among the intersections of the golden dividing lines obtained by dividing the vertical and horizontal directions of the through image by the golden ratio as the specific position (details will be described later). .

  The face detection unit 18b detects a face area from the through image. That is, the face detection unit 18b extracts a face area from the image data of the through image, and detects the position coordinates and size (range) thereof. The position coordinate data and the size (range) data are temporarily recorded in the RAM 13 sequentially. The face detection process can be realized by using a known technique.

  Based on the detection result of the face detection unit, the detection frame display control unit 18c causes the display monitor 19 to superimpose and display a detection frame surrounding the face area on the through image. The coordinate data of the detection frame is temporarily recorded in the RAM 13 sequentially. Note that the image processing unit 12 is responsible for synthesizing a mark or a detection frame with a through image so as to be superimposed on the display monitor 19.

  The position determination unit 18d determines whether or not the positional relationship between the detection frame and the mark is a predetermined positional relationship (details will be described later).

  The face recognition unit 18e performs a feature amount extraction process on the face region detected by the face detection unit 18b to extract a face feature amount. That is, the face recognizing unit 18e extracts from the face region a shape that expresses the facial expression features such as the shape of the face contour, the shape of the eyes, and the shape of the mouth. This feature amount extraction process can be performed by a known technique. The facial expression determination unit 18f determines the facial expression based on, for example, the mouth corner (both sides of the mouth) and the size of the eyes.

  When the determination result of the position determination unit 18d is in a predetermined positional relationship, the shooting control unit 18g determines that it is the shooting timing according to the determination result of the facial expression determination unit 18f, and the imaging control unit 18g Via the timing generator, a drive signal is sent to each of the image sensor and the A / D converter, and still image shooting is performed.

  The notification unit 18h detects the signal from the light receiving sensor 22 when the smile / composition mode is set, and if the signal level of the detected light amount is equal to or lower than the preset light amount signal level, for example, the notification unit 18h A warning is displayed.

  FIG. 2 is a front view and a rear view of the electronic camera 1. The electronic camera 1 of this embodiment is a so-called compact (lens-integrated) electronic camera, and employs a thin housing.

  FIG. 2A is a front view of the electronic camera 1 and includes an incident window 24 that guides incident light to the photographing lens 10 and an incident window 25 that guides incident light to the light receiving element 22.

  FIG. 2B is a rear view of the electronic camera 1. As the display monitor 19 and the operation unit 15, a wide-angle zoom key 15a, a telephoto zoom key 15b, a power button 15c, a mode switch 15d, and a cross key 15e are displayed. Is provided. A release button 16 is provided on the upper surface of the electronic camera 1. In FIG. 2B, it is assumed that a transparent touch panel 17 (not shown) is arranged on the display screen of the display monitor 19.

  The wide-angle zoom key 15a is an operation key for changing the focal length to the wide-angle side. The telephoto zoom key 15b is an operation key for changing the focal length to the telephoto side. The mode switch 15d is an operation key for switching to a shooting mode or a playback mode. The cross key 15e is an operation key for selecting or executing a setting condition of an operation menu of the electronic camera 1.

  Next, an example of the operation of the electronic camera 1 in the first embodiment will be described.

  FIG. 3 is a flowchart showing the photographing operation of the electronic camera 1. In the following description, a case where the smile / composition mode function is set to ON will be described. That is, when the electronic camera 1 is turned on and receives an instruction input for starting a smile / composition mode via the operation unit 15, the CPU 18 starts the processing of this flowchart.

  Step S101: The CPU 18 starts acquiring a through image by driving the image sensor and the A / D converter via the timing generator in the image capturing unit 11. This through image is displayed on the display monitor 19. Subsequently, the landmark display control unit 18a superimposes and displays the landmark for determining the composition on the through image.

  FIG. 4 is a diagram for explaining setting of a mark. As shown in FIG. 4A, for example, the mark display control unit 18a displays the mark M at the center position of the through image (corresponding to the center position of the display screen of the display monitor 19). In addition, the display mode of the mark M is an example, Comprising: It is not limited to this.

  Step S102: The CPU 18 sets the position of the mark M. Specifically, the CPU 18 detects the coordinates of the finger contact position via the touch panel 17. As shown in FIG. 4B, the mark display control unit 18a of the CPU 18 displays the mark M while moving the position of the mark M as the finger contact position moves. Then, when detecting that the movement of the finger contact position has stopped via the touch panel 17, the CPU 18 sets the position of the mark M at that time as the position for determining the composition. The coordinate data of the position for determining the composition is once recorded in the RAM 13.

  For convenience of explanation, the contact position of the finger and the position of the mark M are separated from each other in FIG. 4B, but the contact position of the finger and the position of the mark M may be considered to be the same on the display screen. It is assumed that the photographer moves the mark M by tracing with the finger. Further, when the contact of the finger is not detected via the touch panel 17 even after a predetermined time has elapsed, the CPU 18 sets the center position of the through image as the composition determination position as it is.

  Step S103: The face detection unit 18b of the CPU 18 performs processing for detecting a face region from the through image based on the image data of the through image. That is, the face detection unit 18b tries to extract a face area from the image data. Each time the process of step S103 is repeated, the through image is sequentially read out by the face detection unit 18b, and the process of detecting the face area is performed.

  Step S104: If the face detection unit 18b has detected the face area (step S104: Yes), the process proceeds to step S105. On the other hand, when the face area cannot be detected (step S104: No), the process returns to step S103. Then, the face detection unit 18b performs a process of detecting a face region based on the image data of the next through image that is the target of face detection.

  FIG. 5 is a diagram for explaining the outline of processing from when a face area is detected until shooting is performed.

  Step S105: The detection frame display control unit 18c of the CPU 18 superimposes and displays the detection frame W surrounding the face area of the person P on the through image based on the detection result of the face detection unit 18b, as shown in FIG. Let When a zoom operation or the like is performed, the size of the detection frame W is also enlarged or reduced as the facial area is enlarged or reduced.

  Step S106: The CPU 18 detects the presence / absence of a full-press operation instruction input. When the instruction input of the full press operation is received (step S106: Yes), the process proceeds to step S107. On the other hand, when the instruction input for the full press operation is not accepted (step S106: No), the process of step S106 is repeated.

  Step S107: The position determination unit 18d of the CPU 18 determines the positional relationship between the detection frame W and the mark M. Here, for convenience of explanation, the position determination unit 18d will be described in association with the coordinate system on the display screen.

  The CPU 18 reads the coordinate data of the mark M (position for determining composition) recorded in the RAM 13 and the coordinate data of the detection frame W, and calculates the distance between the center coordinate in the detection frame W and the center coordinate of the mark M. To do. The position determination unit 18d determines the positional relationship between the center coordinates in the detection frame W and the center coordinates of the mark M. When the value of the distance between the center coordinates in the detection frame W and the center coordinates of the mark M has reached a preset threshold value (step S107: Yes), the process proceeds to step S108. For example, when the threshold value is set to 0, the position determination unit 18d determines whether or not the center coordinates match (the distance value between them becomes 0). FIG. 5B shows an example in which the center coordinates in the detection frame W and the center coordinates of the mark M coincide with each other.

  In FIG. 5A, as an example, the CPU 18 first displays the color of the detection frame W in a yellow color. When the center coordinate in the detection frame W matches the center coordinate of the mark M, the CPU 18 may display the color of the detection frame W in green in FIG. As a result, the CPU 18 notifies the photographer that the center coordinates coincide with each other by a change in the color of the detection frame W.

  On the other hand, when the value of the distance between the center coordinate in the detection frame W and the center coordinate of the mark M does not reach the preset threshold value (step S107: No), the process of step S107 is repeated.

  Step S108: The face recognizing unit 18e of the CPU 18 extracts, from the face area, a shape that expresses the facial expression features such as the shape of the face outline, the shape of the eyes, the shape of the mouth, etc. by the feature amount extraction process.

  Step S109: The facial expression determination unit 18f of the CPU 18 determines the facial expression based on the feature amount based on how the mouth corners rise and the size of the eyes. As shown in FIG.5 (c), when a determination result is a smile (step S109: Yes), it transfers to step S110. If the determination result is not smile (step S109: No), the process returns to step S107.

  Step S110: The photographing control unit 18g of the CPU 18 determines that it is the photographing timing, issues an instruction for photographing preparation processing such as AE and AF, and sets the photographing conditions, and then causes the photographing unit 11 to perform still image photographing. Give instructions. Image data output by the imaging unit 11 is input to the image processing unit 12. The image processing unit 12 temporarily records the image data output from the imaging unit 11 in the RAM 13. The image processing unit 12 performs image processing such as white balance correction processing on the image data. The CPU 18 compresses the image data after the image processing and stores it in the recording medium 21.

  Step S111: The CPU 18 determines whether or not an instruction input for ending the smile / composition mode has been received via the operation unit 15. When the instruction input for ending the smile / composition mode is not accepted (step S111: No), the process returns to step S101. When an instruction input for ending the smile / composition mode is received (step S111: Yes), this processing routine ends. Note that, in the processing of step S104, step S106, step S107, and step S109, when a time-out occurs, the CPU 18 cancels the smile / composition mode.

  As described above, according to the electronic camera 1 of the first embodiment, when the value of the distance between the center coordinate in the detection frame W and the center coordinate of the mark M reaches a preset threshold value and the subject is smiling, The imaging control unit 18g causes the imaging unit 11 to perform still image shooting. Therefore, when the electronic camera 1 determines that the subject is smiling and has a desirable composition (when the determination result of the position determination unit 18d reaches the threshold value), the electronic camera 1 determines that it is the shooting timing and performs shooting. Can be performed.

  In the above description, the case where the shooting mode is the smile / composition mode has been described. For example, a shooting mode (composition priority mode) in which still image shooting is performed with priority only on the composition may be further provided. In this case, the processing of step S108 and step S109 is not performed, and the imaging control unit 18g causes the imaging unit 11 to perform still image shooting. That is, the electronic camera 1 can perform photographing by determining that it is the photographing timing when it is determined that the composition is preferable without performing facial expression determination.

  In the above description, smile is selected as the specific facial expression. However, the expression is not limited to a smile and may be an expression other than a smile. This is effective when it is better to select an expression other than a smile depending on the composition to be photographed.

  In the present embodiment, when the smile / composition mode is set, it may be detected whether or not the photographer's finger is reflected in the through image independently of the flowchart shown in FIG.

  FIG. 6 is a diagram for explaining reflection of a finger. As shown in FIG. 6A, in recent years, in a compact electronic camera having a thin casing, a finger F or the like is a part of the entrance window 24 depending on how the photographer holds the electronic camera. May be covered.

  Therefore, the notification unit 18h shown in FIG. 1 detects the signal from the light receiving sensor 22, and if the detected light level is equal to or lower than the preset light level, the finger F or the like is in the incident window 24. For example, as shown in FIG. 6B, a warning display such as “There is a possibility that a finger is reflected in the screen!” Is displayed on the display monitor 19. Let it be done. At this time, the mark setting display control unit 18a may also call attention even if the display mode of the mark M is changed.

  By doing so, the photographer can prevent the finger F from covering a part of the entrance window 24 before photographing. Then, photographing can be performed with a preferable composition. This warning may be after shooting. After shooting, shooting can be performed with a preferred composition in the next shooting.

  Next, a first modification of the first embodiment will be described.

  Conventionally, it has been empirically known that when the main objects in the shooting screen are arranged according to the so-called golden ratio, the shooting screen has a sense of stability. Therefore, the mark display control unit 18a arranges the mark M according to the golden ratio. In other words, the landmark display control unit 18a selects the intersection point of the golden dividing lines obtained by dividing the vertical and horizontal directions of the through image (corresponding to the size of the display screen) displayed on the display monitor 19 by the golden ratio. The mark M is placed on the. Hereinafter, the first modification will be specifically described with reference to FIG.

  FIG. 7 is a diagram illustrating a first modification. In FIG. 7A, the horizontal dimension of the through image (corresponding to the horizontal dimension of the display screen) is a golden ratio of a (1): b (1.618) (here, an approximate value of 1.618). Is adopted). The vertical dimension of the through image (corresponding to the vertical dimension of the display screen) is divided by the golden ratio of c (1): d (1.618). A dotted line G shown in the through image is a golden dividing line. Here, the mark display control unit 18a arranges the mark M on the intersection of the golden dividing lines.

  As shown in FIG. 7B, when the vertical and horizontal directions of the through image are divided by the golden ratio, the horizontal dimension of the through image is a (1.618): b (1) or the vertical dimension of the through image. May be golden-divided by c (1.618): d (1). Therefore, four points (A, B, C, D) are generated as shown in FIG. In this case, it is preferable that the mark display control unit 18a arranges the mark M at the point A or the point C. Therefore, as an example, the mark display control unit 18a first arranges the mark M at the point A. In this state, the mark M may be arranged at the point C by accepting the operation of the cross key 15e.

  FIG. 7C shows the positional relationship between the mark M and the detection frame W. In this case, when the determination result of the position determination unit 18d has a predetermined positional relationship, the shooting control unit 18g captures a still image in the imaging unit 11 if the determination result of the facial expression determination unit 18f is a smile. To do. FIG. 7C illustrates a case where the center coordinates in the detection frame W coincide with the center coordinates of the mark M as a predetermined positional relationship. This makes it easier to obtain a composition that makes the subject smile and brings a sense of stability to the shooting screen.

  Next, a second modification of the first embodiment will be described.

  In the second modification, when the photographer holds the electronic camera from the horizontal position to the vertical position, the mark display control unit 18a considers the vertical position of the electronic camera 1 and arranges the mark M according to the golden ratio. Let Here, the posture detection sensor 23 shown in FIG. 1 detects the rotational position (posture) around the optical axis of the electronic camera 1.

  FIG. 8 is a diagram illustrating a second modification. When the electronic camera 1 is held from the horizontal position (FIG. 2B) to the vertical position (FIG. 8A), the posture detection sensor 23 detects that the electronic camera 1 has been rotated 90 degrees clockwise. To do. When the electronic camera 1 is held from the horizontal position to the vertical position, as shown in FIG. 8A, the position where the cross key 15e is below the display monitor 19 with respect to the ground. When it comes to the relationship, here we define it as clockwise. The opposite is defined as counterclockwise.

  In this case, it is preferable that the mark display control unit 18a arranges the mark M at the point A or the point B in association with FIG. Therefore, as an example, the mark display control unit 18a first arranges the mark M at the point A.

On the other hand, when the electronic camera 1 is held from the horizontal position (FIG. 2B) to the vertical position (FIG. 8B), the attitude detection sensor 23 is rotated 90 degrees counterclockwise. Detect that. In this case, it is preferable that the mark display control unit 18a arranges the mark M at the C point or the D point in association with FIG. Therefore, as an example, when the mark display control unit 18a initially places the mark M at the point A, the mark display control unit 18a places the mark M at the point D. By doing so, it is easy to obtain a composition that brings a sense of stability to the shooting screen even if the shooting is in the vertical position.
(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the second embodiment, the electronic camera 1 detects a plurality of moving subjects and tracks a target subject selected from these subjects. Then, the face detection unit 18b of the electronic camera 1 detects the face area of the subject of interest, and if the subject is a smile as in the first embodiment, the shooting control unit 18g includes a still image in the imaging unit 11. Let the shoot take place. In the first embodiment of the present invention and the second embodiment of the present invention, the same elements are denoted by the same reference numerals and description thereof is omitted. Hereinafter, differences in the configuration of the electronic camera 1 will be described first.

  FIG. 9 is a block diagram illustrating a configuration of the electronic camera 1 according to the second embodiment. In FIG. 9, the CPU 18 further includes a motion detection unit 18i, a subject selection unit 18j, and a tracking unit 18k.

  The motion detector 18i detects the motion of the subject based on the temporal change of the image data of the through image. That is, the motion detection unit 18 i detects the motion of the subject using the through image frames output from the imaging unit 11 at a predetermined frame rate. The motion detector 18i sequentially calculates motion vectors based on known inter-frame differences. Thereby, the motion detector 18i can detect the motion of the subject. The motion detector 18i may detect the motion of the subject using a dedicated circuit for motion detection.

  The subject selection unit 18j receives an instruction input from the photographer and selects a subject of interest from among a plurality of subjects whose movement is detected by the motion detection unit 18i.

  The tracking unit 18k tracks the subject of interest based on the detection result of the motion detection unit 18i. In other words, the tracking unit 18k tracks the subject selected by the subject selection unit 18j by acquiring the coordinates of the current subject from the detection result of the motion detection unit 18i.

  Next, the photographing operation of the electronic camera 1 according to the second embodiment will be described.

  FIG. 10 is a flowchart showing the photographing operation of the electronic camera 1 according to the second embodiment. 11 and 12 are diagrams for explaining an example of a photographing operation in the electronic camera 1 according to the second embodiment. Here, it is assumed that a subject is photographed on a merry-go-round 100 horse at an amusement park. Here, after the electronic camera 1 is turned on, if an instruction input for starting the smile / composition mode with the subject tracking function added is received via the operation unit 15, the CPU 18 performs the processing of the flowchart shown in FIG. Start.

  Step S201: The CPU 18 starts acquiring a through image. As shown in FIG. 11A, the mark display control unit 18a superimposes and displays a line-shaped mark L as a mark on the through image. The line-shaped mark L can also be moved left and right via the touch panel 17.

  Step S202: The motion detector 18i of the CPU 18 receives the through image and starts detecting the motion of the subject. As shown in FIG. 11B, when the motion detection unit 18i detects the movement of the subject, the CPU 18 displays the tracking target mark in a superimposed manner on the through image. In order to make the explanation easy to understand, in this example, marks T1, T2, and T3 representing tracking targets are superimposed and displayed on the horses H1, H2, and H3, respectively. In this example, the subject P is on the horse H1. In step S202, the CPU 18 causes the tracking target mark to be superimposed and displayed on the through image with respect to the sequentially acquired through image.

  Step S203: When the photographer operates the cross key 15e to accept a smile / composition mode end instruction input (step S203: Yes), the processing routine of the flowchart shown in FIG. 10 ends. On the other hand, if the CPU 18 does not accept the end of the smile / composition mode (step S203: No), the process proceeds to step S204.

  Step S204: The CPU 18 determines whether or not there are a plurality of subjects as tracking target candidates. When there are a plurality of tracking target subjects (step S204: Yes), the process proceeds to step S205. When there is a single subject to be tracked (step S204: No), it becomes the subject to be tracked as it is, and the process proceeds to step S206. That is, the subject P is selected as a tracking target as a subject of interest (subject for face detection).

  Step S205: As an example, the subject selection unit 18j of the CPU 18 prompts the photographer to select a subject to be tracked. Subsequently, the CPU 18 detects the coordinates of the contact position of the finger via the touch panel 17. For example, when the coordinates of the portion of the mark T1 superimposed and displayed on the through image are detected, the subject of the mark T1 is selected as a tracking target as a subject of interest (subject to be face-detected). Then, the CPU 18 stops the superimposed display of the marks T2 and T3. Thereby, the superimposed display of the marks T2 and T3 disappears (FIG. 12A).

  Step S206: The CPU 18 determines whether or not a full-press operation instruction is input when the smile / composition mode is set. When the instruction input for the full press operation is not received within the predetermined time (step S206: No), the process returns to the motion detection process in step S202, and starts again from the process in step S202. In this case, since the subject has already been selected, the CPU 18 does not perform the subject selection process or the like (step S204, step S205), and repeats the process of step S206.

  On the other hand, when the CPU 18 receives an instruction input for a full-press operation (step S206: Yes), the process proceeds to step S207.

  Step S207: The face detection unit 18b of the CPU 18 performs a process of continuously detecting a face region from the through image based on the image data of the through image. At this time, the face recognition unit 18e of the CPU 18 extracts, from the face region, a shape in which the feature of the facial expression of the person appears by the feature amount extraction process. Based on the detection result of the face detection unit 18b, the detection frame display control unit 18c of the CPU 18 superimposes and displays the detection frame W surrounding the face area on the through image (FIG. 12A). Further, the tracking unit 18k of the CPU 18 tracks the subject P included in the through image based on the detection result of the motion detection unit 18i.

  Step S208: The position determination unit 18d of the CPU 18 determines the positional relationship between the detection frame W and the mark L. In this example, for the sake of simplicity, the position determination unit 18d determines the center coordinates in the detection frame W and the value of the distance to the point where the mark L intersects when a virtual horizontal line is drawn from the center coordinates. To do. That is, the position determination unit 18d determines whether or not the value of the distance to the point that intersects the mark L has reached a predetermined threshold value. Here, as an example, the threshold value is set to 0. Then, whether or not the threshold value is reached is determined whether or not the center coordinates in the detection frame W have reached the line of the mark L. The determination condition may be whether the right end of the detection frame W shown in FIG. 12B reaches the line L instead of the center coordinates of the detection frame.

  Therefore, when the center coordinate in the detection frame W reaches the line of the mark L (step S208: Yes), the position determination unit 18d proceeds to step S209. On the other hand, when the center coordinates in the detection frame W have not reached the line of the mark L (step S208: No), the process returns to step S202.

  Step S209: The facial expression determination unit 18f of the CPU 18 determines whether the facial expression is a smile based on the feature amount. As shown in FIG. 12B, when the determination result is a smile (step S209: Yes), the process proceeds to step S210. If the determination result is not a smile (step S209: No), the process returns to step S202.

  Step S210: The imaging control unit 18g of the CPU 18 causes the imaging unit 11 to perform still image shooting in the same manner as in the first embodiment. Then, the CPU 18 compresses the image data after the image processing and stores it in the recording medium 21. Then, this processing routine returns to step S202 again. Furthermore, when the end of the smile / composition mode is accepted in step S203 (step S203: Yes), the processing routine of the flowchart shown in FIG. 10 ends.

As described above, according to the electronic camera 1 of the second embodiment, when a plurality of subjects are monitored, the subject's face is smiling when the subject of interest reaches a predetermined position (mark L1). If there is, the imaging control unit 18g causes the imaging unit 11 to perform still image shooting. Therefore, the electronic camera 1 of the second embodiment determines that it is the shooting timing when it is determined that the face of the selected subject among the plurality of moving subjects has a specific facial expression and a preferred composition. Can be taken.
<Supplementary items of the embodiment>
(1) In the first embodiment described above, the case where there is one person is exemplified. However, when a plurality of faces are detected, a plurality of persons are input by the photographer as in the second embodiment. One of them may be selected.

  (2) In the first embodiment and the second embodiment described above, when the subject is smiling, the imaging control unit 18g causes the imaging unit 11 to store a still image according to the positional relationship between the detection frame and the mark M. I was allowed to shoot. For example, using a known technique for extracting a shape representing a specific pose (gesture) of the subject, the imaging control unit 18g may cause the imaging unit 11 to perform still image shooting when the pose is a specific pose. Good. Alternatively, a specific facial expression and a specific pose may be combined.

DESCRIPTION OF SYMBOLS 11 ... Imaging part, 18a ... Mark display control part, 18b ... Face detection part, 18c ... Detection frame display control part, 18e ... Face recognition part, 18f ... Expression determination part, 18g: Shooting control unit, 18i: Motion detection unit, 18j: Subject selection unit

JP 2007-336124 A

Claims (4)

An imaging unit that images a subject and generates image data;
A display unit for displaying an image based on the image data;
A first mark display control unit that superimposes and displays a first mark for determining a composition of still image shooting at a specific position of the through image with respect to a through image that is a moving image acquired for composition confirmation;
An operation unit for inputting information of a position to move the first mark from the specific position to an arbitrary position;
A face detection unit for detecting a face region from the through image;
A second mark display control unit that superimposes and displays a second mark indicating the area of the face on the through image based on a detection result of the face detection unit;
A face recognition unit for extracting the feature amount of the face;
A facial expression determination unit that determines the facial expression based on the feature amount;
A position determination unit that determines whether a distance between the arbitrary position where the first mark is displayed and the position where the second mark is displayed has reached a preset threshold;
When the position determination unit determines that the distance has reached the threshold and the facial expression corresponding to the second mark is a specific facial expression , the imaging unit is configured to perform the still image shooting. A shooting control unit to perform,
An electronic camera comprising: The electronic camera according to claim 1,
An operation unit for selecting a shooting mode for selecting a normal shooting mode and a first mode,
In the normal shooting mode, a signal for instructing automatic exposure and automatic focusing is output in response to a half-press operation, and the still image shooting is performed in response to a full-press operation operated following the half-press operation. A release button for outputting a signal for starting the operation of
When the first mode is selected, the shooting control unit determines that the distance has reached the threshold after performing the full pressing operation of the release button, and the position determination unit, An electronic camera , wherein the still image shooting is automatically executed when the face image has a specific facial expression . The electronic camera according to claim 1 or 2 ,
A motion detection unit that detects a motion of a subject based on a plurality of image data sequentially generated by the imaging unit;
A subject selection unit that selects a subject of interest among a plurality of subjects whose movement is detected by the motion detection unit;
A tracking unit that tracks the subject of interest ;
The electronic camera characterized in that the second mark display control unit superimposes and displays a second mark indicating the face area of the subject of interest on the through image . The electronic camera according to any one of claims 1 to 4 ,
Detection means for detecting whether the photographer's finger is reflected;
An electronic camera comprising: warning means for displaying a warning externally before or after taking the still image in response to detection of reflection of a photographer's finger by the detection means .

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