JP2007208355A - Imaging apparatus, method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire an image in a preferable state especially where the face of a character looks toward the front in a photographing device, such as a digital camera. <P>SOLUTION: In the digital camera 1, a CCD 58 captures successively photographed images, and a face determination section 80 determines whether a face is included in the images. When the face is included, it is further determined whether the face looks toward the front. When the face looks toward the front, a captured image is recorded in an external recording medium 70. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photographing apparatus such as a digital camera for obtaining an image by photographing, a photographing method, and a program for causing a computer to execute the photographing method.

  Various methods have been proposed for causing a digital camera to automatically shoot. For example, Patent Document 1 discloses that when a shape representing a facial expression of a human subject is repeatedly extracted from an image captured by a camera, and the degree of coincidence between the extracted subject shape and a predetermined shape exceeds a predetermined value. There has been proposed a method of automatically taking a picture when the subject has a facial expression or pose that seems desirable.

Further, in Patent Document 2, it is determined that the shooting state is poor when a part of the person as a subject is overlapped or the part is missing or when the face of the person is not facing the front, There has also been proposed a method in which a person who is a subject is warned and shooting is automatically performed when the shooting state becomes good.
JP 2004-294498 A Japanese Patent Laid-Open No. 2005-3852

  However, when shooting is performed automatically as described above, the state of the subject may change due to a time lag from the shutter operation until the image is acquired. In particular, when the subject is a child, it is difficult to maintain a stationary state, and therefore, an image in which a person's face is not facing front is often acquired even if automatic shooting is performed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to acquire an image in a preferable state in which a person's face is facing the front in a photographing apparatus such as a digital camera.

The first imaging apparatus according to the present invention includes an imaging unit that acquires an image of a subject by imaging the subject by a shooting operation;
In a photographing apparatus provided with a recording means for recording the image,
When the photographing operation is performed, images captured by the imaging unit are sequentially captured, and it is determined whether or not the captured image includes a face. When the captured image includes the face, the face is turned to the front. Face determination means for determining whether or not
And a recording control unit that records the captured image in the recording unit when it is determined that the face is facing the front.

The second imaging apparatus according to the present invention includes an imaging unit that acquires an image of a subject by imaging the subject by a shooting operation;
In a photographing apparatus provided with a recording means for recording the image,
A recording control unit that records an image captured by the imaging unit in the recording unit when the photographing operation is performed;
Face determination means for determining whether or not a face is included in the recorded image and determining whether or not the face is facing the front when the face is included;
Warning means for giving a warning when it is determined that the face does not face the front is provided.

According to a first imaging method of the present invention, an imaging unit that acquires an image of a subject by imaging the subject by a photographing operation;
In a photographing method in a photographing apparatus comprising a recording means for recording the image,
When the shooting operation is performed, sequentially capture images captured by the imaging unit,
Determine whether the captured image contains a face,
If the face is included, determine whether the face is facing the front,
When it is determined that the face is facing the front, the captured image is recorded in the recording means.

A second photographing method according to the present invention is a photographing method in a photographing apparatus comprising a recording unit for recording the image.
When the photographing operation is performed, the image captured by the imaging unit is recorded in the recording unit,
Determine whether the recorded image contains a face,
If the face is included, determine whether the face is facing the front,
A warning is given when it is determined that the face is not facing the front.

  In addition, you may provide as a program for making a computer perform the 1st and 2nd imaging | photography method by this invention.

  According to the first image capturing apparatus and method of the present invention, when an image capturing operation is performed, images captured by the image capturing unit are sequentially captured, it is determined whether the captured image includes a face, and the face is included. If it is determined whether the face is facing the front. Then, the captured image is recorded in the recording means when facing the front. For this reason, it is possible to acquire an image with the face always facing the front regardless of the time lag of the shutter.

  According to the second image capturing apparatus and method of the present invention, when an image capturing operation is performed, an image captured by the image capturing unit is recorded in the recording unit, and it is determined whether or not the recorded image includes a face. Is included, it is further determined whether or not the face is facing the front. And when it determines with not facing the front, a warning is performed. For this reason, the photographer can redo the photographing when a warning is given, and thus, an image with the face always facing the front can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view centering on the back surface of a digital camera 1 which is a first embodiment of a photographing apparatus of the present invention. As shown in FIG. 1, an operation mode switch 11, a menu / OK button 12, a zoom / up / down arrow lever 13, a left / right arrow button 14, a back are provided on the back of the digital camera 1 as an interface for operations by a photographer. In addition to having a (return) button 15 and a display switching button 16, it has a finder 17 and a liquid crystal monitor 18. A release button 19 is provided on the upper surface. FIG. 2 is a perspective view centering on the front surface of the digital camera 1 according to the first embodiment. As shown in FIG. 2, a lens 20, a lens cover 21, a power switch 22, a finder window 23, a strobe 24, and a self-timer lamp 25 are provided on the front surface.

  The operation mode switch 11 is a slide switch for switching operation modes of a still image shooting mode, a moving image shooting mode, and a playback mode.

  When the menu / OK button 12 is pressed, various menus for setting the shooting mode, the flash emission mode, the number of recording pixels, the sensitivity, and the like are displayed on the liquid crystal monitor 18 or the menu displayed on the liquid crystal monitor 18 is displayed. This is a button for confirming selection / setting based on the. The menu / OK button 12 can be used to set the shooting mode to an auto mode for automatically setting exposure and white balance and a manual mode for manually setting.

  The zoom / up / down arrow lever 13 is used to adjust the telephoto / wide angle during shooting by tilting the lever in the vertical direction, and to move the cursor in the menu screen displayed on the liquid crystal monitor 18 up and down during various settings. The lever.

  The left and right arrow buttons 14 are buttons for moving the cursor in the menu screen displayed on the liquid crystal monitor 18 to the left and right at various settings.

  The Back button 15 is a button for stopping various setting operations when pressed and returning to the previous screen.

  The display switching button 16 is a button for switching ON / OFF of the display of the liquid crystal monitor 18, various guide displays, ON / OFF of character display, and the like when pressed.

  The contents set by the operation of each button and lever can be confirmed by the display on the liquid crystal monitor 18, the position of the lamp in the finder, the slide lever, and the like.

  The liquid crystal monitor 18 displays a through image for confirming a subject at the time of shooting, thereby functioning as an electronic viewfinder, displaying a still image and a moving image after shooting, and displaying various setting menus.

  FIG. 3 is a schematic block diagram showing the configuration of the digital camera which is the first embodiment of the photographing apparatus of the present invention. The digital camera 1 shown in FIG. 3 converts image data acquired by shooting into an Exif format image file and records it on an external recording medium 70 that can be attached to and detached from the main body.

  The operation system of this digital camera includes the above-described operation mode switch 11, menu / OK button 12, zoom / up / down arrow lever 13, left / right arrow button 14, Back button 15, display switch button 16, release button 19, The power switch 22 and an operation system control unit 74 which is an interface part for transmitting the operation contents of these switches to the CPU 75 are provided.

  The optical system includes a focus lens 20a and a zoom lens 20b. Each lens can be moved in the optical axis direction by a focus lens driving unit 51 and a zoom lens driving unit 52 including a motor and a motor driver. The focus lens driving unit 51 controls the movement of each lens based on the focus driving amount data output from the AF processing unit 62 and the zoom lens driving unit 52 based on the operation amount data of the zoom / up / down arrow lever 13. .

  The diaphragm 54 is driven by a diaphragm driving unit 55 including a motor and a motor driver. The aperture driver 55 adjusts the aperture diameter based on aperture value data output from the AE / AWB processor 63.

  The shutter 56 is a mechanical shutter and is driven by a shutter drive unit 57 including a motor and a motor driver. The shutter drive unit 57 controls the opening / closing of the shutter 56 in accordance with a signal generated by pressing the release button 19 and the shutter speed data output from the AE / AWB processing unit 63.

  A CCD 58, which is an image sensor, is provided behind the optical system. The CCD 58 has a photoelectric surface in which a large number of light receiving elements are two-dimensionally arranged, and subject light that has passed through the optical system forms an image on the photoelectric surface and is subjected to photoelectric conversion. In front of the photocathode, a microlens array for condensing light on each pixel and a color filter array in which filters of R, G, and B colors are regularly arranged are arranged. The CCD 58 outputs the charges accumulated for each pixel as a serial analog photographing signal line by line in synchronization with the vertical transfer clock and horizontal transfer clock supplied from the CCD controller 59. The time for accumulating charges in each pixel, that is, the exposure time is determined by an electronic shutter drive signal given from the CCD controller 59.

  The analog photographing signal captured from the CCD 58 is input to the analog signal processing unit 60. The analog signal processing unit 60 includes a correlated double sampling circuit (CDS) that removes noise from the analog signal, an auto gain controller (AGC) that adjusts the gain of the analog signal, and an A / D that converts the analog signal into a digital signal. It consists of a converter (ADC). The image data converted into the digital signal is CCD-RAW data having R, G, and B density values for each pixel.

  The timing generator 72 generates a timing signal. By supplying this timing signal to the shutter drive unit 57, the CCD control unit 59, and the analog signal processing unit 60, the operation of the release button 19, the opening and closing of the shutter 56, The charge taking of the CCD 58 and the processing of the analog signal processing unit 60 are synchronized.

  The strobe control unit 73 causes the strobe 24 to emit light during shooting.

  The image input controller 61 writes the CCD-RAW data input from the analog signal processing unit 60 in the frame memory 66.

  The frame memory 66 is a working memory used when various digital image processing (signal processing) described later is performed on image data. For example, an SDRAM (data transfer device that performs data transfer in synchronization with a bus clock signal having a fixed period. Synchronous Dynamic Random Access Memory) is used.

  The display control unit 71 displays the image data stored in the frame memory 66 on the liquid crystal monitor 18 as a through image, or displays the image data stored in the external recording medium 70 on the liquid crystal monitor 18 in the reproduction mode. Is for. The through image is taken by the CCD 58 at a predetermined interval while the shooting mode is selected.

  The AF processing unit 62 and the AE / AWB processing unit 63 determine shooting conditions based on the pre-image. This pre-image is an image represented by image data stored in the frame memory 66 as a result of the CPU 75 having detected a half-press signal generated by half-pressing the release button 19 causing the CCD 58 to perform pre-photographing. It is.

  The AF processing unit 62 detects the focal position based on the pre-image and outputs focus drive amount data (AF processing). As a focus position detection method, for example, a passive method that detects a focus position using a feature that the contrast of an image is high in a focused state can be considered.

  The AE / AWB processing unit 63 measures subject brightness based on the pre-image, determines an aperture value, shutter speed, etc. based on the measured subject brightness, and determines aperture value data and shutter speed data as exposure setting values. At the same time (AE processing), white balance at the time of shooting is automatically adjusted (AWB). The exposure and white balance can be set manually by the user of the digital camera 1 when the shooting mode is set to the manual mode. Even when the exposure and white balance are set automatically, the user can manually adjust the exposure and white balance by giving an instruction from the operation system such as the menu / OK button 12.

  As will be described later, the image processing unit 64 performs image quality correction processing such as gamma correction, sharpness correction, and contrast correction on the image data of the main image in which it is determined that the person's face is facing the front, CCD-RAW data. Is converted into YCC data consisting of Y data as a luminance signal, Cb data as a blue color difference signal, and Cr data as a red color difference signal. The main image is image data that is sequentially captured from the CCD 58 in the main photographing executed when the release button 19 is fully pressed, and is sequentially stored in the frame memory 66 via the analog signal processing unit 60 and the image input controller 61. It is an image by. The upper limit of the number of pixels of the main image is determined by the number of pixels of the CCD 58. For example, the number of recorded pixels can be changed by setting such as fine and normal. On the other hand, the number of images of the through image and the pre-image is smaller than that of the main image.

  At the time of actual shooting, the process of acquiring the main image (that is, the capturing of the image pickup signal by the CCD 58 and the processing in the analog signal processing unit 60) has the human face included in the main image facing the front as described later. Repeated until state is reached.

  The compression / decompression processing unit 65 performs, for example, JPEG compression on the image data of the main image that has been corrected and converted by the image processing unit 64 and has been determined that the person's face is facing the front. Perform compression processing in the format to generate an image file. A tag storing incidental information such as shooting date and time is added to the image file based on the Exif format or the like. In the reproduction mode, the compression / decompression processing unit 65 reads the compressed image file from the external recording medium 70 and performs the decompression process. The decompressed image data is output to the liquid crystal monitor 18.

  The media control unit 67 accesses the external recording medium 70 and controls writing and reading of the image file.

  The internal memory 68 stores various constants set in the digital camera 1, programs executed by the CPU 75, and the like.

  The face determination unit 80 determines whether or not the main image sequentially acquired by the main photographing includes a face. If the face is included, the face determination unit 80 determines whether or not the face is facing the front. If the face is facing the front, a message to that effect is output to the CPU 75. When a plurality of persons are included in the main image, it is determined whether or not the faces of all persons are facing the front. Whether or not the face is facing the front is determined using the number of persons included in the subject to be photographed, which is input to the digital camera 1 by the photographer and stored in the internal memory 68 before photographing. Here, whether or not a person's face is included is determined by determining whether or not a region having a facial feature included in the face (for example, having a skin color or having a face shape) is included in the image. However, the present invention is not limited to this.

  The CPU 75 controls each part of the main body of the digital camera 1 according to signals from the operation system such as the operation mode switch 11 and various processing units such as the AF processing unit 62.

  The data bus 76 is connected to the image input controller 61, various processing units 62 to 65, a frame memory 66, a media control unit 67, an internal memory 68, a display control unit 71, a face determination unit 80, and a CPU 75. Exchange data.

  Next, processing performed at the time of actual photographing in the digital camera 1 having the above configuration will be described. FIG. 4 is a flowchart showing processing performed at the time of actual photographing in the first embodiment.

  When the release button 19 is fully pressed, the CPU 75 starts processing, and the face determination unit 80 captures the main image captured by the CCD 58 and converted into a digital signal by the analog signal processing unit 60 (step ST1). Next, it is determined whether or not a face is included in the main image (step ST2). If step ST2 is affirmed, a front face determination process is performed (step S3). If step ST2 is negative, the process proceeds to step ST5 described later.

  FIG. 5 is a flowchart of the front face determination process. In addition, although the front face determination process shall use the method described, for example in Unexamined-Japanese-Patent No. 2004-336265, it is not limited to this. First, the face determination unit 80 extracts eye candidates from the main image (step ST11). Specifically, a wavelet transform is performed on the main image, and a wavelet coefficient having an appropriate position and frequency is extracted and quantized to extract a feature portion that can be regarded as an eye candidate as an eye candidate.

  Next, the degree of coincidence between the extracted eye candidate data and the eye dictionary data created by performing the same feature extraction process from a number of sample images is calculated (step ST12). Then, it is determined whether or not the number of eye candidates whose coincidence exceeds a predetermined threshold value Th1 matches the number of eyes corresponding to the number of subjects registered by the photographer (step ST13). That is, when the number of registered subjects is 2, it is determined whether or not the number of eye candidates is 4.

  If step ST13 is affirmed, information indicating that the faces of the persons included in the main image are all facing the front is output (step ST14), and the process returns. If step ST13 is negative, information indicating that there is a person who is not facing the front is output (step ST15), and the process returns.

  Returning to FIG. 4, following step ST <b> 3, it is determined whether all persons are facing the front (step ST <b> 4). If step ST <b> 4 is negative, the process returns to step ST <b> 1 to capture a new main image, The processes after step ST1 are repeated.

  If step ST4 is affirmed, the image processing unit 64 performs image quality correction processing and YCC processing on the main image currently being processed (step ST5), and displays the processed main image on the liquid crystal monitor 18 as well as externally. Recording is performed on the recording medium 70 (step ST6), and the actual photographing process is terminated.

  As described above, in the first embodiment, it is determined whether or not a face is included in the main image. If a face is included, it is further determined whether or not all faces are facing the front. When the face is facing the front, the captured main image is subjected to image quality correction processing and YCC processing and recorded on the external recording medium 70. For this reason, it is possible to acquire an image with the face always facing the front regardless of the time lag of the shutter.

  In the first embodiment, the analog signal processing unit 60 determines whether or not the face of a person included in the main image converted into a digital signal is facing the front. A determination may be made as to whether or not the person's face is facing the front using the main image that has undergone the processing at 64. In this case, the main image determined to be facing the front is immediately recorded on the external recording medium 70.

  Next, a second embodiment of the present invention will be described. FIG. 6 is a schematic block diagram showing the configuration of a digital camera which is the second embodiment of the photographing apparatus of the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted here. The digital camera 1 </ b> A according to the second embodiment records the main image acquired by the main shooting on the external recording medium 70, and whether the face determination unit 80 includes a face in the main image recorded on the external recording medium 70. It is determined whether or not a face is included, and it is determined whether or not the face is facing the front. The warning unit 82 issues a warning when the face is not facing the front.

  Next, processing performed in the second embodiment will be described. Also in the second embodiment, it is assumed that the number of persons included in the subject to be photographed by the photographer is input to the digital camera 1 and stored in the internal memory 68 before photographing.

  When the release button 19 is fully pressed, the CPU 75 starts processing, and the image processing unit 64 performs image quality correction processing and image processing on the main image captured by the CCD 58 and converted into a digital signal by the analog signal processing unit 60. YCC processing is performed (step ST21), and the processed main image is displayed on the liquid crystal monitor 18 and recorded on the external recording medium 70 (step ST22).

  Next, the face determination unit 80 determines whether or not a face is included in the main image recorded on the external recording medium 70 (step ST23). If step ST23 is affirmed, the front face determination process shown in FIG. 5 is performed. It performs (step S24). If step ST23 is negative, the process is terminated.

  Subsequent to step ST24, it is determined whether all persons are facing the front (step ST25). If step ST25 is affirmed, the process ends. If step ST25 is negative, the warning unit 82 issues a warning (step ST26) and ends the process.

  The warning performed by the warning unit 82 may be, for example, a message such as “Please take another shot” on the liquid crystal monitor 18 as shown in FIG. A specific warning sound may be output. Further, a lighting unit such as an LED may be provided in the main body of the digital camera 1 and a warning may be issued by lighting or blinking the lighting unit.

  As described above, according to the second embodiment of the present invention, the main image is recorded on the external recording medium 70, and it is determined whether or not the recorded main image includes a face. It is determined whether or not the face is facing the front, and a warning is given when it is determined that the face is not facing the front. For this reason, the photographer can redo the photographing when a warning is given, and thus, an image with the face always facing the front can be obtained.

  In the second embodiment, an image determined not to face all persons may be recorded on the external recording medium 70 as it is, but is deleted from the external recording medium 70. You may do it.

  As described above, the digital camera according to the embodiment of the present invention has been described. However, the computer functions as a unit corresponding to the face determination unit 80 and the warning unit 82, and performs the processes shown in FIGS. The program to be executed is also one embodiment of the present invention. A computer-readable recording medium in which such a program is recorded is also one embodiment of the present invention.

The perspective view centering on the back surface of the digital camera which is 1st Embodiment of the imaging device of this invention The perspective view centering on the front of the digital camera which is 1st Embodiment of the imaging device of this invention 1 is a schematic block diagram showing the configuration of a digital camera that is a first embodiment of a photographing apparatus of the present invention. The flowchart which shows the process performed in 1st Embodiment. Front face determination processing flowchart 1 is a schematic block diagram showing the configuration of a digital camera that is a second embodiment of the photographing apparatus of the present invention. The flowchart which shows the process performed in 2nd Embodiment. Figure showing an example of a warning

Explanation of symbols

1 Digital camera 18 LCD monitor 58 CCD
59 CCD control unit 64 Image processing unit 70 External recording medium 71 Display control unit 75 CPU
80 Face determination part 82 Warning part

Claims (6)

Imaging means for obtaining an image of the subject by imaging the subject by a photographing operation;
In a photographing apparatus provided with a recording means for recording the image,
When the photographing operation is performed, images captured by the imaging unit are sequentially captured, and it is determined whether or not the captured image includes a face. When the captured image includes the face, the face is turned to the front. Face determination means for determining whether or not
An imaging apparatus comprising: a recording control unit that records the captured image in the recording unit when it is determined that the face is facing the front. Imaging means for obtaining an image of the subject by imaging the subject by a photographing operation;
In a photographing apparatus provided with a recording means for recording the image,
A recording control unit that records an image captured by the imaging unit in the recording unit when the photographing operation is performed;
Face determination means for determining whether or not a face is included in the recorded image and determining whether or not the face is facing the front when the face is included;
An imaging apparatus comprising: warning means for giving a warning when it is determined that the face is not facing the front. Imaging means for obtaining an image of the subject by imaging the subject by a photographing operation;
In a photographing method in a photographing apparatus comprising a recording means for recording the image,
When the shooting operation is performed, sequentially capture images captured by the imaging unit,
Determine whether the captured image contains a face,
If the face is included, determine whether the face is facing the front,
An imaging method comprising: recording the captured image in the recording unit when it is determined that the face is facing the front. Imaging means for obtaining an image of the subject by imaging the subject by a photographing operation;
In a photographing method in a photographing apparatus comprising a recording means for recording the image,
When the photographing operation is performed, the image captured by the imaging unit is recorded in the recording unit,
Determine whether the recorded image contains a face,
If the face is included, determine whether the face is facing the front,
An imaging method, wherein a warning is issued when it is determined that the face is not facing the front. Imaging means for obtaining an image of the subject by imaging the subject by a photographing operation;
In a program for causing a computer to execute a photographing method in a photographing apparatus provided with a recording means for recording the image,
A procedure for sequentially capturing images captured by the imaging means when the photographing operation is performed;
A procedure for determining whether a face is included in the captured image;
A procedure for determining whether the face is facing forward when the face is included;
And a program for recording the captured image in the recording means when it is determined that the face is facing the front. Imaging means for obtaining an image of the subject by imaging the subject by a photographing operation;
In a program for causing a computer to execute a photographing method in a photographing apparatus provided with a recording means for recording the image,
A procedure for recording an image captured by the imaging unit in the recording unit when the photographing operation is performed;
A procedure for determining whether a face is included in the recorded image;
A procedure for determining whether the face is facing forward when the face is included;
A program that issues a warning when it is determined that the face is not facing the front.

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