JP4574459B2 - Image capturing apparatus, control method therefor, program, and storage medium - Google Patents

Description

  The present invention relates to an image pickup apparatus that recognizes a face of a subject from a picked-up image and continuously performs shooting control according to the face of each subject to provide a user-desired image when shooting a person as a subject.

  Imaging devices such as digital cameras are provided with various functions in order to eliminate shooting failures. For example, exposure, focusing, white balance, exposure, etc. are automatically set according to the subject. It also has a function that allows you to shoot while changing the set values of exposure control, focus control, white balance control, etc. step by step by pressing the shutter button once.

  In addition, an imaging apparatus that has a special setting mode specific to a person has been proposed. Generally, in a camera that automatically selects one of a plurality of distance measuring points and focuses on the selected distance measuring point, the distance measuring point closest to the distance is in focus. There is.

  When taking a group photo, if the closest subject (object) that is not intended by the photographer enters one of the multiple AF points, the subject (object) is in focus. As a result, there was a problem that the focus was not on the subject.

  In order to solve the above problem, a method has been proposed in which the face of a subject is recognized, eyes are detected from the face image, and focus information is obtained in accordance with the detected eyes (Patent Document 1).

  In addition, a method has been proposed for recognizing a subject and a shooting scene, and automatically setting an optimum shooting mode from a plurality of shooting modes, thereby shooting a good photo according to the subject and the scene ( Patent Document 2).

The automatic shooting mode selection here is based on the state of the subject (subject movement, subject position, subject brightness, photographing time, number of people), and the camera automatically takes a photographing mode (Av priority, Tv priority, etc.). Is set.
For example, when a person's face is detected within the angle of view, if the number of people is one, “Portrait Mode” is set, the person is in focus, and the rest of the background is blurred as much as possible. Set the aperture to reduce the depth and shoot. If the number of people is 3 or less, the “multi-person mode” is set, and each person is in focus. Do and shoot. If the number of people is four or more, the “group photo mode” is set, and the whole person and background are set to be in harmony.
JP 2001-215403 A JP 2003-344891 A

  However, in the conventional example, when there are a plurality of persons within the angle of view in a situation where the depth of field is shallow and it is difficult to focus, an image with an optimal exposure control is obtained after focusing on a plurality of persons. It was very difficult to shoot.

  As an example of a situation in which the depth of field is shallow and it is difficult to focus, situations such as sports events and sports photography are conceivable. In such a situation, it is expected that the distance to the subject will be long. Therefore, since a telephoto lens is used and the movement of the subject is larger than usual, it is necessary to increase the shutter speed. As a result, the amount of light incident on the lens is reduced and the captured image becomes dark, so the aperture is opened to increase the total amount of incident light (exposure amount). Therefore, the depth of field becomes shallow.

  Also, when shooting in dark places such as night scenes, the amount of light entering the lens is reduced, so the flash output is adjusted by the flash when the flash fires. , The depth of field becomes shallower.

  Similarly, when the light emission amount is insufficient (the distance to the subject is too far or too close), the depth of field becomes shallow because the aperture is opened.

  Furthermore, even if you use a function that changes the exposure, focus, white balance, exposure, etc. settings step by step by pressing the shutter button once, each setting value matches the brightness and subject distance of the main subject. Without it, the photographer could not capture the desired image.

  Therefore, the present invention recognizes the faces of a plurality of subjects, performs grouping from imaging parameters such as subject distance and subject luminance with respect to the faces, sets optimal imaging parameters for each group, and shoots, An object of the present invention is to provide an imaging device capable of performing imaging with imaging parameters optimum for each subject.

In order to solve the above-described problems and achieve the object, an imaging apparatus of the present invention includes an imaging unit that obtains image data by converting a subject image into an electrical signal, and a plurality of subjects in which the subject exists from the image data obtained by the imaging unit. recognition means for recognizing a region, a calculation unit configured to calculate a subject distance and object luminance from the image data of the recognized plurality of regions by said recognition means, the object distance and the subject luminance calculated by the calculating means Grouping means for grouping the plurality of regions, and setting means for setting imaging parameters for each group grouped by the grouping means, and for each group set by the setting means The imaging is based on the imaging parameters.

The imaging apparatus of the present invention in order to achieve the object by solving the above problems, an imaging means for obtaining image data by converting an object image into an electrical signal, a plurality of present subject from image data obtained by said image pickup means recognition means for recognizing a region of said calculation means for calculating the coordinate value of the subject distance and the subject from the image data of the recognized plurality of regions by the recognition unit, the object distance and the calculated by the calculation means based on the coordinate value of the subject, the comprises a grouping means for grouping a plurality of areas, and setting means for setting the respective imaging parameters for each grouped group by the group unit, set by the setting means It was based on the imaging parameters for each group, and is characterized in take a picture.

  By recognizing faces, grouping from recognized face imaging parameters, and setting imaging parameters for each group, it is possible to perform imaging with imaging parameters that are optimal for each subject and obtain suitable captured images. It becomes possible.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram illustrating a configuration example of an imaging apparatus according to an embodiment of the present invention.

  Reference numeral 100 denotes an imaging apparatus having a function of recognizing a face and continuously photographing the face. Reference numeral 11 denotes a photographing lens, 10 denotes a lens barrier which is a protective means for preventing the dirt and damage of the image pickup unit by covering the image pickup unit including the lens 11 of the image pickup apparatus 100, 12 denotes a shutter having an aperture function, and 14 denotes a shutter. An image sensor that converts an optical image that has passed through 12 into an electrical signal, and an A / D converter 16 that converts an analog signal output from the image sensor 14 into a digital signal. A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26, and is controlled by the memory control circuit 22 and the system control circuit 50.

  Reference numeral 50 denotes a system control circuit that controls the entire imaging apparatus 100, and 52 denotes a system memory that stores constants, variables, programs, and the like for operation of the system control circuit 50.

  An image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on data from the A / D converter 16 or data from a memory control circuit 22 described later. Further, the image processing circuit 20 performs predetermined calculation processing using the captured image data, and the system control circuit 50 controls the exposure control circuit 40 and the distance measurement control circuit 42 based on the obtained calculation result. Through-the-lens (hereinafter referred to as TTL) autofocus (hereinafter referred to as AF) processing, automatic exposure (hereinafter referred to as AE) processing, and flash pre-flash (hereinafter referred to as EF) processing. .

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

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

  Reference numeral 24 denotes an image display memory, 26 denotes a D / A converter, and 28 denotes an image display circuit composed of a TFT / LCD. The display image data written in the image display memory 24 passes through the D / A converter 26. Are displayed by the image display unit 28. If image data captured using the image display unit 28 is sequentially displayed, an electronic viewfinder (hereinafter referred to as EVF) function can be realized. Further, the image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control circuit 50. When the display is turned off, the power consumption of the imaging apparatus 100 can be significantly reduced. I can do it.

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a storage capacity sufficient to store a predetermined number of still images and a moving image for a predetermined time. This makes it possible to write a large amount of images to the memory 30 at high speed even in continuous shooting or panoramic shooting in which a plurality of still images are continuously shot. The memory 30 can also be used as a work area for the system control circuit 50.

  The data of the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processing circuit 20 and the memory control circuit 22 or the data of the A / D converter 16 is directly passed through the memory control circuit 22. It is.

  Reference numeral 32 denotes a compression / decompression circuit that compresses and decompresses image data by adaptive discrete cosine transform (ADCT), wavelet transform, etc., and reads the image stored in the memory 30 to perform compression processing or decompression processing. Is written into the memory 30.

  Reference numeral 40 denotes an exposure control circuit that controls the shutter 12 having a diaphragm function, and has a flash light control function in cooperation with the flash device 48.

  Reference numeral 42 denotes a focus adjustment circuit that controls focusing of the photographic lens 11, 44 denotes a zoom control circuit that controls zooming of the photographic lens 11, and 46 denotes a barrier control circuit that controls the operation of the lens barrier 11.

  A flash unit 48 has an AF auxiliary light projecting function and a flash light control function. The exposure control circuit 40 and the distance measurement control circuit 42 are controlled using the TTL method. Based on the calculation result obtained by calculating the captured image data by the image processing circuit 20, the system control circuit 50 performs the exposure control circuit 40 and the distance measurement. Control is performed on the control circuit 42.

  Reference numeral 99 denotes an external recording medium such as a memory card or a hard disk. Further, it is assumed that the external recording medium can acquire the currently available free space. In the present embodiment, the external recording medium 99 is described as being built in the imaging apparatus 100.

  Reference numeral 54 denotes a display unit such as a liquid crystal display device or a speaker that displays an operation state or a message using characters, images, voices, or the like in accordance with execution of a program in the system control circuit 50. A single or a plurality of locations are installed near the easily visible position, and are constituted by a combination of, for example, an LCD, an LED, and a sounding element.

  The display unit 54 is partly installed in an optical viewfinder 29 described later. Among the display contents of the display unit 54, what is displayed on the LCD or the like is, for example, single shot / continuous shooting display, self-timer display, compression rate display, number of recorded pixels, number of recorded images, number of remaining images that can be captured , Shutter speed display, Aperture value display, Exposure compensation display, Flash display, Red-eye reduction display, Macro shooting display, Buzzer setting display, Clock battery level display, Battery level display, Error display, Multi-digit number information display Detachment status display of external recording medium 99, communication I / F operation display, date / time display, display of image files stored in recording medium, display of list of image file names stored in recording medium, external computer Display that shows the connection status with an external digital camera, display that shows the connection status with an external digital camera, Display indicating the state of transmission and reception of data, such as, and the like.

  Further, among the display contents of the display unit 54, what is displayed in the optical viewfinder 29 is, for example, in-focus display, shooting preparation completion display, camera shake warning display, flash charge display, flash charge completion display, shutter speed display, There are an aperture value display, an exposure correction display, a recording medium writing operation display, and the like.

  Further, among the display contents of the display unit 54, what is displayed on the LED or the like includes, for example, in-focus display, photographing preparation completion display, camera shake warning display, camera shake warning display, flash charge display, flash charge completion display, recording medium There are a writing operation display, a macro shooting setting notification display, a secondary battery charge state display, and the like. And what is displayed on a lamp etc. among the display contents of the display part 54 includes a self-timer notification lamp, for example. This self-timer notification lamp may be used in common with AF auxiliary light.

  Reference numeral 56 denotes an electrically erasable / recordable nonvolatile memory such as an EEPROM or a flash memory.

  The face recognition circuit 58 recognizes and detects whether or not there is a face in the subject image, and a considerable method has already been realized as a face recognition technique.

  For example, Japanese Patent Application Laid-Open No. 52-156624 proposes a method for extracting skin color data from an original image and extracting a cluster of photometric points determined as a skin color range as a method for extracting a human face from a captured image. ing.

  Japanese Patent Laid-Open No. 4-346333 discloses a method in which photometric data is converted into hue and saturation, and a face area is determined by creating and analyzing this two-dimensional histogram. A method has been proposed in which a face candidate area corresponding to the shape of a human face is extracted, and the face area is determined from the feature amount in the area.

  Furthermore, the outline of a person's face is extracted from the image, a face area is determined, or a template having a plurality of face shapes is prepared, and the correlation between the template and the image is calculated. As a result, methods such as extracting human faces have been proposed.

  The image synthesis circuit 59 synthesizes an image by inputting a plurality of image data recognized and detected by the face recognition circuit 58, and synthesizes and outputs it as one image.

  Reference numerals 60, 62, 64, 70, and 72 are operation devices for inputting various operation instructions of the system control circuit 50. One or a plurality of operation devices such as a switch, a dial, a touch panel, pointing by gaze detection, a voice recognition device, and the like. Composed of a combination.

  Here, a specific description of these operating devices will be given.

  Reference numeral 60 denotes a power switch (main switch) that can switch and set the power-on and power-off modes of the image processing apparatus 100. In addition, the power on and power off settings of various accessory devices connected to the image processing apparatus 100 can be switched and set together.

  Reference numeral 62 denotes a shutter switch SW1, which is turned on when a shutter button (not shown) is half-pressed and instructs to start operations such as AF processing, AE processing, AWB processing, and EF processing.

  A shutter switch SW2 64 is turned on when a shutter button (not shown) is fully pressed, and a signal read from the image sensor 12 is written into the memory 30 via the A / D converter 16 and the memory control circuit 22. Exposure processing, development processing using operations in the image processing circuit 20 and the memory control circuit 22, recording processing for reading out image data from the memory 30, compression in the compression / decompression circuit 32, and writing the image data to the external recording medium 99 The operation start of a series of processes is instructed.

  The operation unit 70 includes various buttons and a touch panel. A menu button, a set button, a macro button, a multi-screen playback page break button, a flash setting button, a face recognition and continuous shooting / single shooting / continuous shooting / self-timer switching button, Menu move + (plus) button, menu move-(minus) button, playback image move + (plus) button, playback image-(minus) button, shooting image quality selection button, exposure compensation button, date / time setting button, image display ON / OFF button, compression mode switch, quick review switch for setting a quick review function that automatically reproduces and displays image data taken immediately after photographing using the image display unit 28, and various types when performing photographing and reproduction or communication Select / changeover switch for setting and switching functions, shooting Fine reproduction, or various functions and user settings in performing the communication, and the like determined / execution switch for determination and execution of such property setting for the image. Note that one of the properties for the image includes a compression permission attribute for the image to be operated.

  In the compression rate selection mode switch, for example, to select a compression rate such as a JPEG (Joint Photographic Expert Group) compression method, or to select a CCD RAW mode in which an image sensor signal is digitized and recorded on a recording medium. Switch.

  For example, a normal mode, a fine mode, and an economy mode are prepared as compression rate selection modes. The user of the image capturing apparatus 100 can perform shooting by selecting the normal mode or economy mode when emphasizing the data size of the captured image and selecting the fine mode when emphasizing the image quality of the captured image. .

  In the compression rate selection mode, image data read from the image sensor 14 and written in the memory 30 is read and compressed via the A / D converter 16, the image processing circuit 20, and the memory control circuit 22. Compressed to the compression rate set by the decompression circuit 32 and recorded on the external recording medium 99.

  In the CCD RAW mode, the image data is read as it is for each line in accordance with the pixel arrangement of the color filter of the image sensor 14, and the image data written in the memory 30 via the A / D converter 16 and the memory control circuit 22. Are recorded on the external recording medium 99.

  Reference numeral 72 denotes a mode dial switch which can switch and set various function modes such as an automatic shooting mode, a shooting mode, a panoramic shooting mode, a playback mode, a multi-screen playback / erase mode, a PC connection mode, and a camera connection mode.

  Reference numeral 80 denotes a power control circuit, which includes a battery detection circuit, a DC-DC converter, a switch circuit that switches a block to be energized, and the like. In addition, the DC-DC converter is controlled based on an instruction from the system control circuit 50, and a necessary voltage is supplied to each unit including the recording medium for a necessary period.

  Reference numerals 82 and 84 denote connectors, 86 denotes a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, NiMH battery or Li-ion battery, an AC adapter, or the like.

  Reference numeral 90 denotes a recording medium interface with a recording medium such as a memory card or a hard disk.

  A communication circuit 33 has various communication functions such as RS232C, USB (Universal Serial Bus), IEEE 1394, modem, wired communication such as LAN (Local Area Network), infrared communication such as IrDA (Infrared Data Association), and optical communication. Any one of the configurations or a configuration including a plurality of them may be used.

  Next, the photographing operation of the present invention will be described using the flowchart shown in FIG.

  FIG. 2 is a flowchart illustrating the imaging process of the present embodiment.

  In this imaging process, imaging according to the face is performed by detecting and recognizing the face of the subject.

  In step S201, the system control circuit 50 turns on the power of the imaging apparatus, and the imaging apparatus is activated in the imaging mode.

  If the photographer changes the shooting mode to the face recognition continuous shooting mode in step S202, the process proceeds to step S203.

  In step S203, the system control circuit 50 determines whether the shutter switch SW1 has been pressed. If SW1 is not pressed, the process is repeated until SW1 is pressed. If SW1 is pressed, the process proceeds to step S204.

  In step S204, the face recognition circuit 58 performs processing for recognizing the face area of the subject.

  In step S205, the face recognition circuit 58 determines whether the face has been recognized. If the face can be recognized, the process proceeds to step S206. If the face cannot be recognized, the process proceeds to step S209.

In step S206, various imaging parameters are calculated for each face recognized in step S204.
In this embodiment, the distance to the subject, the luminance value of the face area, that is, the subject luminance value (hereinafter referred to as Bv value), the exposure value (hereinafter referred to as Ev value), the shutter speed value (hereinafter referred to as Tv value), the aperture Although the value (hereinafter referred to as the Av value) is calculated as the imaging parameter, the imaging parameter is not limited to these.

  In step S207, face grouping is performed based on the various imaging parameter information calculated in step S206, and processing for setting optimal imaging parameters for the group is performed.

  In step S208, the system control circuit 50 notifies the user through the display unit 54 that the face has been recognized using characters / images. The photographer may be notified using sound.

  In step S209, the system control circuit 50 notifies the user using characters / images or the like via the display unit 54 that the face could not be recognized. The photographer may be notified using sound.

  In step S210, the system control circuit 50 determines whether or not the shutter switch SW2 has been pressed. If the shutter switch SW2 has not been pressed, the process proceeds to step S212, and a predetermined time has elapsed since the shutter switch SW1 was pressed. Judge whether or not.

  In step S212, if the predetermined time has not elapsed since the shutter switch SW1 was pressed, the process proceeds to step S210, and if the predetermined time has been exceeded, the process returns to step S203 to perform the process.

  If the shutter switch SW2 is pressed in step S210, the system control circuit 50 sets the imaging parameter for each group in step S211, performs shooting for each group, and stores the image.

  FIG. 3 is a flowchart illustrating in detail the face recognition process in step S204 of FIG.

  In step S301, the focus adjustment circuit 42 that controls focusing is used, and the system control circuit 50 performs focus detection.

  In step S <b> 302, the system control circuit 50 writes the signal read from the image sensor 12 into the memory 30 via the A / D converter 16, the image processing circuit 20, and the memory control circuit 22.

  In step S303, the face recognition circuit 58 performs face recognition processing from the image data written in the memory 30 in step S302.

  FIG. 4 is a flowchart illustrating in detail the imaging parameter calculation processing for the recognized face in step S206 of FIG.

  In step S401, predetermined calculation processing is performed using the face image data, and the system control circuit 50 controls the distance measurement control circuit 42 based on the calculation result to calculate the subject distance to the recognized face. .

  In step S402, the system control circuit 50 controls the exposure control circuit 40 to calculate the subject brightness of the recognized face.

  In step S403, the system control circuit 50 performs an automatic exposure process to calculate an Av value, a Tv value, and a gain value (hereinafter referred to as a Gain value).

  In step S404, the system control circuit 50 determines whether imaging parameters have been calculated for all recognized faces. If the imaging parameters have not been calculated for all the faces, the system control circuit 50 repeats the processing from step S401. If the imaging parameters have been calculated for all faces, the process ends.

  FIG. 5 is a flowchart illustrating in detail the process of grouping faces in step S207 of FIG. 2 and setting imaging parameters for each grouped group.

  In step S501, the system control circuit 50 performs grouping based on the subject distance among the imaging parameters of each face calculated in step S206.

  In step S502, the system control circuit 50 determines whether grouping has been completed for all faces. If grouping has been completed for all faces, the system control circuit 50 advances the process to step S503. If the grouping has not been completed for all the faces, the system control circuit 50 returns the process to step 501.

  In step S503, the system control circuit 50 further groups the faces existing in the group grouped according to the subject distance based on the luminance values of various imaging parameters related to the face area calculated in step S206. Thus, by subdividing the group, the accuracy of the imaging parameters suitable for the face divided for each group is improved.

  In step S504, the system control circuit 50 determines whether group subdivision has been completed for all groups. If segmentation has been completed for all groups, the system control circuit 50 advances the processing to step S505. If segmentation has not been completed for all groups, the system control circuit 50 returns the process to step S503.

  In step S505, the system control circuit 50 calculates and sets various imaging parameters related to the face area existing in the group.

  In step S506, the system control circuit 50 determines whether imaging parameters have been set for all groups. If the imaging parameters are set for all groups, the system control circuit 50 ends the process. If the imaging parameters are not set for all groups, the system control circuit 50 returns the process to step S505.

  FIG. 6 is a flowchart illustrating in detail the grouping process for the subject distance in step S501 of FIG.

  In step S601, the system control circuit 50 determines the subject distance obtained in step S401. When the subject distance is “A” which is the closest, and “B”, “C”, and “D” are in this order, and the subject distance is not applied to any group, the system control circuit 50 determines the face in step S611. Is not subject to photography.

  If the subject distance is “A” to “B”, the system control circuit 50 determines whether group 1 exists in step S702. If group 1 does not exist, group 1 is created in step S603, and the process proceeds to step S604. If group 1 exists, the process of step S604 is performed. In step S604, the system control circuit 50 registers the subject's face in the group 1.

  If the subject distance is “B” to “C”, the system control circuit 50 determines whether group 2 exists in step S605. If group 2 does not exist, group 2 is created in step S606, and the process proceeds to step S607. If group 2 exists, the process of step S607 is performed. In step S607, the system control circuit 50 registers the subject's face in the group 2.

When the subject distance is “C” to “D”, in step S608, the system control circuit 50 determines whether the group 3 exists. If group 3 does not exist, group 3 is created in step S609, and the process proceeds to step S610. If group 3 exists, the process of step S610 is performed. In step S610, the system control circuit 50 registers the face of the subject in the group 3.
In the present embodiment, the group is divided into three groups and the other groups into four groups. However, the number of group divisions is not limited to four.

  FIG. 7 is a flowchart illustrating in detail the process of subdividing the group according to the subject brightness in step S503 of FIG.

  In step S701, the system control circuit 50 determines the subject brightness obtained in step S402. As for the subject brightness, in the case of a face having “P” being the darkest and brightening in the order of “Q”, “R”, “S”, and subject brightness not applied to any group, the system control circuit 50 in step S711. Makes the face asymmetric.

  When the subject brightness is “P” to “Q”, the system control circuit 50 determines whether group (x) −1 exists in step S702. If group (x) -1 does not exist, group (x) -1 is created in step S703, and the process proceeds to step S704. If group (x) -1 exists, the process of step S704 is performed. In step S704, the system control circuit 50 registers the face of the subject in the group (x) -1.

  When the subject brightness is “Q” to “R”, the system control circuit 50 determines whether group (x) -2 exists in step S705. If group (x) -2 does not exist, group (x) -2 is created in step S706, and the process proceeds to step S707. If group (x) -2 exists, the process of step S707 is performed. In step S707, the system control unit 50 registers the face of the subject in the group (x) -2.

  When the subject brightness is “R” to “S”, the system control unit 50 determines whether group (x) -3 exists in step S708. If group (x) -3 does not exist, group (x) -3 is created in step S709, and the process proceeds to step S710. If group (x) -3 exists, the process of step S710 is performed. In step S710, the system control unit 50 registers the face of the subject in the group (x) -3.

  In step S712, the system control unit 50 determines whether all the faces in the group have been grouped. If grouping has been completed for all faces in the group, the process ends. If grouping has not been completed for all faces in the group, the system control unit 50 returns the process to step S701.

  FIG. 8 is a flowchart illustrating in detail processing for setting imaging parameters for each group.

  In step S801, the system control unit 50 calculates the average luminance value of the faces in the group.

  In step S802, the system control unit 50 calculates a Tv value, an Av value, and a ΔGain value from the luminance value calculated in step S801.

  In step S803, the system control unit 50 determines whether imaging parameters have been set for all groups. If the system control unit 50 has not set imaging parameters for all groups, the processing from step S801 is repeated. If the system control unit 50 has set imaging parameters for all groups, the process ends. Note that when calculating the Tv value, Av value, and ΔGain value from the subject luminance value in Step S801, the Tv value, Av value, and ΔGain value may be changed depending on the shooting mode. For example, in the portrait mode, a setting is made to open the aperture (reduce the Av value) so as to make the depth of field as shallow as possible. In the sport mode, setting is made to increase the shutter speed (decrease the Tv value). In other shooting modes, processing is performed so as to calculate the imaging parameters intended by the photographer.

  FIG. 17 is an example of a diagram summarizing various imaging parameters related to the recognized face area.

  The components are the subject distance of the face, the subject brightness Bv value, the exposure Ev value, the shutter speed Tv value, and the aperture Av value.

  In step S501, the face areas are grouped based on the subject distance. Group 1 is set to 0.5 m to 1.5 m, Group 2 is set to 1.5 m to 2.5 m, and Group 3 is set to 2.5 m to 3.5 m. If the imaging asymmetry is otherwise set, group 1 can be grouped with face 1 and face 2, group 2 with face 3 and face 4, group 3 without, and shooting asymmetry with face 5.

  In step S503, the faces are grouped again from the subject brightness Bv value, but the group x-1 is 2 to 4, the group x-2 is 4 to 6, the group x-3 is 6 to 9, and the others are photographed. If it is asymmetric, face 1 and face 2 of group 1 can be grouped as group 1-1, group 1-2 as face 1, and group 1-3 as face 2. Face 3 and face 4 of group 2 can be grouped as group 1-1, group 2-2 as face 3 and face 4, and group 2-3 as none.

In step S505, an Av value, a Tv value, and a Gain value are set for each of the groups 1-2, 1-3, and 2-2.
Then, photographing is performed for each group in which imaging parameters are set.

  In the present embodiment, grouping is performed in groups of three based on the subject distance and subject brightness, but the number of groupings is not limited to three, and the distance width (the farthest subject) The number of groups may be increased or decreased according to the difference between the distance and the nearest subject distance) or the brightness width (the difference between the highest subject brightness and the lowest subject brightness), or the user may set in advance Good.

  Note that the present invention is not limited to the configurations of these embodiments, and any configuration may be used as long as the functions indicated in the claims or the functions of the embodiments can be achieved. Needless to say.

  Further, although an example applied to a digital camera is described, the present invention may be applied to various forms such as a video camera and a copying machine.

  As described above, in this embodiment, the face of the subject is recognized from the imaging scene, and grouping is performed from various imaging parameters such as the subject distance to the face and the subject luminance, and the optimum imaging parameter is set for each group. By continuously photographing, it is possible to easily photograph the main subject desired by the photographer with optimum imaging parameters.

(Second Embodiment)
The operation of the present embodiment will be described in detail with reference to the drawings. The same step number is assigned to the step that performs the same processing as in the first embodiment.

  This embodiment is different from the first embodiment in that the first embodiment groups faces based on subject distance and subject brightness, whereas in this embodiment, subject distance and face coordinates are different. The grouping is based on the position.

  FIG. 9 is a flowchart illustrating the imaging process of the present embodiment.

  FIG. 9 is different from FIG. 2 in the flowchart describing the imaging processing of the first embodiment when a human face is detected, and the other processing is the same as FIG. A description of steps S201 to S205 and steps S208 to S209 corresponding to this portion will be omitted.

  If it is determined that the subject's face has been recognized as in the first embodiment, in step S901, the system control circuit 50 calculates various imaging parameters relating to the recognized face area.

  In step S902, the system control circuit 50 performs face grouping using the various imaging parameter information calculated in step S901, and performs processing for newly setting imaging parameters for each group.

  In step S210, system control circuit 50 determines whether or not shutter switch SW2 has been pressed. In step S210, if SW2 is not pressed, the process proceeds to step S212, and the same process as in the first embodiment is repeated.

  If SW2 is pressed in step S210, the system control circuit 50 advances the process to step S903.

  In step S903, the system control circuit 50 sets an imaging parameter for each group, performs imaging, and stores an image.

  FIG. 10 is a flowchart illustrating in detail the various imaging parameter calculation processing related to the recognized face area in step S901 in FIG.

  In step S401, predetermined calculation processing is performed using the face image data, and the system control circuit 50 controls the distance measurement control circuit 42 based on the calculation result to calculate the subject distance to the recognized face. .

  In step S402, the system control circuit 50 controls the exposure control circuit 40 to calculate the subject brightness of the recognized face.

  In step S403, the system control circuit 50 performs an automatic exposure process to calculate an Av value, a Tv value, and a Gain value.

  In step S1001, the system control circuit 50 calculates the coordinate position of the recognized face.

  In step S404, the system control circuit 50 determines whether imaging parameters have been calculated for all recognized faces. If the imaging parameters have not been calculated for all the faces, the system control circuit 50 repeats the processing from step S401. If the imaging parameters have been calculated for all faces, the process ends.

  FIG. 11 is a flowchart illustrating in detail the process of performing face grouping and setting imaging parameters for a group in step S902 of FIG.

  In step S501, the system control circuit 50 performs grouping based on the subject distance among the imaging parameters of each face calculated in step S206.

  In step S502, the system control circuit 50 determines whether all the faces have been grouped. If all the faces have been grouped, the process of step S1101 is performed. If not, the process of step 501 is returned.

  In step S1101, the system control circuit 50 subdivides the group from the coordinates of faces existing in the group. By subdividing the group, the accuracy of imaging parameters suitable for the face is improved.

  In step S504, the system control circuit 50 determines whether the groups have been subdivided for all groups. If group subdivision has been performed for all groups, step S505 is performed. If not, the process of step S1101 is returned.

  In step S505, the system control circuit 50 calculates and sets imaging parameters from the faces present in the group.

  In step S506, the system control circuit 50 determines whether imaging parameters have been set for all groups. If imaging parameters have been set for all groups, the process ends. If not set, the process of step S505 is returned.

  FIG. 12 is a flowchart illustrating in detail the process of subdividing the group according to the face coordinate data of the subject in step S1101 of FIG.

  In step S1201, the system control circuit 50 acquires a reference face coordinate value. Note that when selecting a reference face, the face may be weighted by subject distance. Further, the weight may be changed in conjunction with the photometry method or the focus frame.

  In step S1202, the system control circuit 50 determines the number of group subdivisions based on the range where the face exists, and creates a coordinate area to be grouped. For example, when the coordinate (x, y) of the reference face is (100, 200), the coordinates (0, 100) to (300, 400) of the X coordinate plus 100 / minus 100 and the Y coordinate plus 100 / minus 100 are used. Is the coordinate area to be grouped.

  In step S1203, the system control circuit 50 acquires the coordinate positions of other faces in the screen.

  In step S <b> 1204, the system control circuit 50 compares the reference face with the coordinate values of other faces and determines whether the face exists in the grouping area.

  In step S1204, if there is no face that satisfies the grouping condition in the area to be grouped, the system control circuit 50 advances the process to step S1207.

  In step S1204, if a face that satisfies the grouping condition exists in the grouping area, the process proceeds to step S1206, and the system control circuit 50 registers the face as the same group.

  In step S1206, the system control circuit 50 determines whether coordinate values have been checked for all faces in the group.

  If the coordinates have not been checked for all the faces in the group in step S1206, the process returns to step S1203.

  If the coordinates have been checked for all faces in the group in step S1206, the process ends.

  FIG. 13 is a flowchart illustrating in detail the process of grouping again from the face coordinate data in step S1101 of FIG. 11 by the matrix method.

  In step S1301, the system control circuit 50 creates a matrix. As the matrix, for example, a matrix that is divided into three vertically and three horizontally is created, and the coordinate value of each matrix is obtained.

  In step S1302, the system control circuit 50 compares the matrix coordinates with the face image.

  In step S1303, the system control circuit 50 determines whether the face coordinates exist within a certain matrix area.

  If the face coordinates are present within one matrix area, the process advances to step S1307.

  In step S1307, the system control circuit 50 registers the face in the matrix in which the face exists.

  On the other hand, if the face coordinates do not exist within one matrix area, the process advances to step S1305.

  In step S1305, the system control circuit 50 calculates the face area in each matrix.

  In step S1306, the system control circuit 50 registers the face in the matrix having the largest area.

In step S1308, system control circuit 50 determines whether all faces have been compared with matrix coordinates. If it is compared, the process is terminated. If not compared, the process returns to step S1302.
FIG. 17 is a diagram illustrating an example of various imaging parameters related to the recognized face area.

  The subject distance of the face, coordinates (x, y), luminance Bv value, exposure Ev value, shutter speed Tv value, and aperture Av value.

  Reference numeral 1901 denotes a monitor of the image pickup apparatus, which represents a matrix that is divided into three vertically and three horizontally. The ordinate is divided by 0, 500, 1000, 1500, and the abscissa is divided by 0, 400, 800, 1200. Reference numeral 1903 denotes a face of a subject, which is a face existing in one matrix. Reference numeral 1902 denotes a face of the subject, but a face straddling a plurality of matrices.

  Here, the coordinates of the face 1902 of the subject across a plurality of matrices are (300, 200) to (550, 430), and (0, 0) to (500, 400), (500, 0) to (1000). , 400), (0, 400) to (500, 800), (500, 400) to (1000, 800). When the area of each matrix is obtained, it becomes 40000, 10000, 6000, 1500, and the matrix of (0, 0) to (500, 400) becomes the widest. Therefore, the face 1902 is registered in the matrices (0, 0) to (500, 400).

  In step S501, the subject distance is grouped, but group 1 is set to 0.5 m to 1.5 m, group 2 is set to 1.5 m to 2.5 m, group 3 is set to 2.5 m to 3.5 m, and other than that, photographing asymmetry is performed. Then, group 1 can be grouped with face 1 and face 2, group 2 can be grouped with face 3 and face 4, group 3 is not available, and shooting asymmetry can be grouped with face 5.

  In step S1101, the group is subdivided from the coordinates (x, y), but the ordinate is 0, 500, 1000, 1500, the abscissa is 0, 400, 800, 1200, Then, since the face 1 and the face 2 of the group 1 are both faces existing in the matrices (0, 0) to (500, 400), it is not necessary to subdivide the group 1.

Since the face 3 and the face 4 of the group 2 are faces existing in the matrix (0,0) to (500,400) and the matrix (1000,0) to (1500,400), respectively, the group is subdivided.
As a result, the groups are subdivided, such as face 1 and face 2 of group 1, face 3 of group 2, and face 4 of group 3.

  In step S505, the system control circuit 50 sets an Av value, a Tv value, and a Gain value for each group. Then, photographing is performed for each group in which imaging parameters are set.

  FIG. 15 is a flowchart illustrating in detail processing for setting imaging parameters for each group.

  In step S1501, the system control circuit 50 determines whether or not a pre-registered face exists in the captured screen.

  If the registered face is present in the captured screen, the system control circuit 50 sets the registered face imaging parameter as the imaging parameter of the group to which the registered face belongs in step S1502. In addition, when there are a plurality of registered faces in the same group, this is dealt with by obtaining an average value of imaging parameters of the plurality of faces.

  If the registered face does not exist in the captured screen, the system control unit 50 calculates the average luminance value of the faces in the group in step S801.

  In step S802, the system control unit 50 calculates a Tv value, an Av value, and a ΔGain value from the luminance value calculated in step S801.

  In step S803, the system control unit 50 determines whether imaging parameters have been set for all groups. If the system control unit 50 has not set imaging parameters for all groups, the processing from step S1501 is repeated. If the system control unit 50 has set imaging parameters for all groups, the process ends.

  FIG. 14 is a diagram showing an Exif compressed data file structure of a captured image.

  Reference numeral 1401 denotes a file recording format of the JPEG compression method, in which an application marker segment (APP1) is inserted immediately after the SOI marker representing the head of the file, and Exif additional information is described in APP1.

  Reference numeral 1402 denotes an internal configuration of APP1, and APP1 includes an APP1 marker, an Exif identification code, and an attached information main body. The attached information takes a TIFF structure including a file header and can record a maximum of two IFDs (0th IFD, 1st IFD). In the 0th IFD, auxiliary information regarding the compressed image (main image) is recorded. A thumbnail image can be recorded in the 1st IFD.

  1403 is an Exif IFD for recording Exif-specific attached information in the 0th IFD. The information attached to the Exif IFD can be recorded with user information starting from the version information. There is a manufacturer note area in the user information. The manufacturer enters individual information in the manufacturer note area, and the operation is left to the manufacturer. By registering the coordinates of the recognized face in the maker note area, it is possible to notify the user of the recognized face at the time of image reproduction.

  FIG. 16 is a monitor image diagram when the user is notified of the face recognized at the time of image reproduction.

  In this embodiment, grouping is performed based on the subject distance and the coordinate position of the subject, and grouping is performed by performing grouping twice. However, the number of times of grouping is determined depending on shooting conditions. It may be increased or decreased.

  As described above, in the present embodiment, the faces of a plurality of subjects are recognized, and the nearby faces are grouped from the imaging parameters such as the subject distance to the face and the coordinate data of the subjects, so that each subject can be identified. Optimal shooting can be easily performed.

  In addition, by notifying the photographer of the recognized face, it is possible to check whether the photographer has recognized the desired face, thereby reducing shooting failures.

  Further, in each of the above-described embodiments, grouping is performed by performing face recognition, but it is not limited to face recognition, and by performing recognition of the subject itself using a known subject recognition technique, Grouping may be performed.

  As described above, the present invention detects a plurality of subjects that satisfy a predetermined condition, further divides the detected plurality of subjects into a plurality of groups using different conditions, and for each of the plurality of groups. The present invention is not limited to the above-described embodiment as long as the shooting parameters are set and shooting is performed.

  Another object of the present invention is to supply a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and the computer (or CPU or CPU) of the system or apparatus. Needless to say, this can also be achieved by the MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included. Examples of the storage medium for storing the program code include a flexible disk, hard disk, ROM, RAM, magnetic tape, nonvolatile memory card, CD-ROM, CD-R, DVD, optical disk, magneto-optical disk, MO, and the like. Can be considered. Also, a computer network such as a LAN (Local Area Network) or a WAN (Wide Area Network) can be used to supply the program code.

It is a block diagram which shows the structure of the electric circuit at the time of applying to the digital camera in embodiment of this invention. It is the flowchart figure explaining the imaging process in the 1st Embodiment of this invention. It is a flowchart figure explaining the face recognition process in the 1st Embodiment of this invention in detail. It is the flowchart figure explaining the imaging parameter calculation process of the recognized face area in the 1st Embodiment of this invention in detail. It is the flowchart figure which demonstrated in detail the process which performs the grouping of the face in the 1st Embodiment of this invention, and sets an imaging parameter with respect to a group. It is a flowchart figure explaining in detail the process which groups from the object distance in the 1st Embodiment of this invention. It is a flowchart figure explaining in detail the process which subdivides a group according to the to-be-photographed object brightness | luminance in the 1st Embodiment of this invention. It is the flowchart figure explaining in detail the process which sets an imaging parameter with respect to each group in the 1st Embodiment of this invention. It is a flowchart figure explaining the imaging process in the 2nd Embodiment of this invention. It is the flowchart figure explaining in detail the imaging parameter calculation process of the recognized face area in the 2nd Embodiment of this invention. It is the flowchart figure which demonstrated in detail the process which performs the grouping of the face in the 2nd Embodiment of this invention, and sets an imaging parameter with respect to a group. It is the flowchart figure explaining in detail the process which groups again from the face coordinate data in the 2nd Embodiment of this invention. It is a flowchart figure explaining in detail the process which groups again by the matrix system from the face coordinate data in the 2nd Embodiment of this invention. It is the figure which showed the Exif compression data file structure of the picked-up image. It is the flowchart figure explaining in detail the process which sets an imaging parameter with respect to each group in the 2nd Embodiment of this invention. It is a monitor image figure at the time of notifying a user of the face recognized at the time of image reproduction. It is an example figure which put together the imaging parameter regarding the recognized face area. It is a monitor image figure at the time of grouping of the face by a matrix system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens barrier 11 Shooting lens 12 Shutter 14 Image sensor 16 A / D converter 18 Timing generation circuit 20 Image processing circuit 22 Memory control circuit 24 Image display memory 26 D / A converter 28 Image display part 30 Memory 32 Compression / decompression circuit 33 Communication circuit 40 Exposure control circuit 42 Distance control circuit 44 Zoom control circuit 46 Barrier control circuit 48 Flash device 50 System control circuit 52 System memory 54 Display unit 56 Non-volatile memory 58 Face recognition circuit 59 Image composition circuit 60 Main switch 62 Shutter Switch SW1
64 Shutter switch SW2
DESCRIPTION OF SYMBOLS 70 Operation part 72 Mode dial switch 80 Power supply control circuit 82 Connector 86 Power supply device 90 Interface for recording media 99 External recording medium 100 Imaging device

Claims (7)

Imaging means for converting the subject image into an electrical signal to obtain image data;
Recognizing means for recognizing a plurality of areas where a subject exists from image data obtained by the imaging means;
Calculation means for calculating subject distance and subject brightness from the image data of the plurality of areas recognized by the recognition means;
Grouping means for grouping the plurality of regions based on the subject distance and the subject brightness calculated by the calculating means;
Setting means for setting imaging parameters for each group grouped by the grouping means,
An imaging apparatus that performs imaging based on imaging parameters for each group set by the setting unit. Imaging means for converting the subject image into an electrical signal to obtain image data;
Recognizing means for recognizing a plurality of areas where a subject exists from image data obtained by the imaging means;
Calculating means for calculating a subject distance and a coordinate value of the subject from the image data of the plurality of areas recognized by the recognition means;
Grouping means for grouping the plurality of regions based on the subject distance and the coordinate value of the subject calculated by the calculating means;
Setting means for setting imaging parameters for each group grouped by the grouping means,
An imaging apparatus that performs imaging based on imaging parameters for each group set by the setting unit.   The imaging apparatus according to claim 1, wherein photographing is performed for each group grouped by the grouping unit. An imaging step of converting a subject image into an electrical signal to obtain image data;
A recognition step for recognizing a plurality of regions where a subject exists from the image data obtained in the imaging step;
A calculation step of calculating subject distance and subject luminance from the image data of the plurality of regions recognized in the recognition step;
A grouping step of grouping the plurality of regions based on the subject distance and the subject luminance calculated in the calculation step;
A setting step of setting imaging parameters for each group grouped in the grouping step;
An imaging apparatus control method comprising: an imaging process for performing imaging based on an imaging parameter for each group set in the setting process. An imaging step of converting a subject image into an electrical signal to obtain image data;
A recognition step for recognizing a plurality of regions where a subject exists from the image data obtained in the imaging step;
A calculation step of calculating a subject distance and a coordinate value of the subject from the image data of the plurality of regions recognized in the recognition step;
A grouping step for grouping the plurality of regions based on the subject distance and the coordinate value of the subject calculated in the calculation step;
A setting step of setting imaging parameters for each group grouped in the grouping step;
An imaging apparatus control method comprising: an imaging process for performing imaging based on an imaging parameter for each group set in the setting process .   6. The method of controlling an imaging apparatus according to claim 4, wherein in the photographing step, photographing is performed for each of the groups grouped by the grouping step.   A program for causing a computer to execute the control method according to claim 4.

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