JP2014096836A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preferable image which has sufficient operability, in which possibility of occurrence of release time lag is eliminated and to which image processing is applied.SOLUTION: A digital camera includes: an imaging section for acquiring an image; a correction section for performing prescribed correction on the image acquired by the imaging section; a face detection section for detecting a face of a subject from the image which the imaging section acquires: a determining section for determining whether a state of the face which the face detection section detects satisfies a prescribed condition or not; and a control section for performing control the correction section to carry out the prescribed correction on the image where the state of the face is determined to satisfy the prescribed condition by the determining section and to accept an instruction whether the correction section performs the prescribed correction or not from a user on the image where the state of the face is determined not to satisfy the prescribed condition by the determining section.

Description

  The present invention relates to a digital camera that acquires an image.

  2. Description of the Related Art Conventionally, as a method for obtaining a preferable image, a digital camera that extracts a person part from a photographed image of a person and performs continuous photographing when the photographing state of the person is bad is known (Patent Document 1). Such).

  In addition, a digital camera that generates a preferable image by performing image processing on an image obtained by photographing is known. For example, the following digital camera of Non-Patent Document 1 automatically recognizes the face of a person included in an image, and adjusts the exposure conditions at the time of shooting so that the recognized face has a beautiful impression. And a makeup function for performing image processing on an image obtained by photographing.

JP 2005-045601 A

Casio Computer Co., Ltd. EXILIM ZOOM EX-Z300 Instruction Manual

  However, in the digital camera of Patent Document 1, the timing at which the user operates the shutter button is different from the timing at which an image is actually obtained by continuous shooting, and thus it is not always possible to capture an image at a desired timing.

  In the digital camera disclosed in Non-Patent Document 1, the user sets in advance whether to apply the makeup function to an image obtained by shooting, and the makeup function is applied according to the setting. Therefore, there is a problem that the operation becomes complicated. In order to avoid this problem, it is conceivable to always apply a makeup function to an image obtained by shooting without the above setting. However, since image processing for make-up takes several seconds (about 3 seconds), there is a problem in that rapid photographing and responsiveness are poor when it is desired to continuously photograph images.

  Therefore, the digital camera 1 of the present invention aims to obtain a preferable image that has good operability, reduces the possibility of a release time lag, and applies image processing.

  The digital camera of the present invention detects an object's face from an image capturing unit that acquires an image, a correction unit that performs a predetermined correction on the image acquired by the image capturing unit, and the image acquired by the image capturing unit. A face detection unit; a determination unit that determines whether or not the state of the face detected by the face detection unit satisfies a predetermined condition; and the state of the face satisfies the predetermined condition by the determination unit The correction unit controls the correction unit to perform the predetermined correction, and for the image determined by the determination unit that the face state does not satisfy the predetermined condition, the correction unit A control unit that controls to accept an instruction from a user as to whether or not to perform the predetermined correction.

  According to the digital camera of the present invention, the operability is good, the possibility of a release time lag being reduced, and a preferable image to which image processing is applied can be acquired.

It is a block diagram which shows the structure of the digital camera 1 in embodiment of this invention. 4 is a flowchart illustrating an operation at the time of image capturing in the digital camera 1. It is a figure which shows the example of an image with a subject's blink, and the example of an image without a blink. It is a figure which shows the example of the display part 8 at the time of reproduction | regeneration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a digital camera 1 according to an embodiment of the present invention. As shown in FIG. 1, the digital camera 1 includes an imaging lens 2, an imaging device 3, an A / D conversion unit 4, a buffer memory 5, an image processing unit 6, a control unit 7, a display unit 8, an operation unit 9, and a recording I. / F unit 10, recording medium 11, and bus 12.

  The imaging lens 2 forms a subject image on the imaging surface of the imaging element 3. The imaging lens 2 may be an imaging optical system including a plurality of lenses such as a zoom lens and a focus lens. The imaging element 3 photoelectrically converts the subject light that has passed through the imaging lens 2 and outputs analog image signals corresponding to R, G, and B colors. The imaging device 3 performs thinning-out reading at predetermined intervals during imaging standby and acquires a through image. Thereafter, the image sensor 3 acquires the main image when a release button 15 described later is fully pressed.

  An image signal output from the image sensor 3 is input to the A / D converter 4. The A / D conversion unit 4 performs A / D conversion on the analog image signal output from the image sensor 3 and changes it to a digital image signal. The digital image signals are collected into one frame and recorded in the buffer memory 5 as image data. The buffer memory 5 temporarily records image data in the pre-process and post-process of image processing by the image processing unit 6.

  The image processing unit 6 performs image processing on the image data recorded in the buffer memory 5. Examples of the image processing include well-known white balance adjustment, color interpolation, gradation conversion processing, and contour enhancement processing. The image processing unit 6 also executes a process of compressing in JPEG (Joint Photographic Experts Group) format or the like before recording an image file on the recording medium 11 and a process of decompressing and restoring the compressed data.

  The image processing unit 6 performs skin beautification processing. This skin beautification process is an image process performed on the main image, and includes the following processes.

  For example, the image processing unit 6 performs exposure correction for correcting the exposure of the image to the over side. Thereby, a preferable image in which the skin of the subject is expressed white can be obtained.

  The image processing unit 6 performs soft focus processing. Thereby, when a subject is a woman, while femininity is emphasized, a preferable image with softness can be obtained. In addition, it is possible to obtain a preferable image in which wrinkles and rough skin of the subject are not noticeable.

  In addition, the image processing unit 6 may correct the parameters of saturation and lightness to express the skin white or reduce the dullness of the skin color.

  Further, the image processing unit 6 performs correction to make the person included in the image look slim. For example, the image processing unit 6 changes the aspect ratio of the image to be slightly long and then cuts out a person portion and adjusts the size of the image. Alternatively, the image processing unit 6 may correct the outline of the face and make the cheek look thin as disclosed in Japanese Patent Application Laid-Open No. 2004-264893.

  In addition, the image processing unit 6 adjusts feature portions (eyebrows, eyes, mouth, etc.) in the face. For example, the image processing unit 6 performs correction for enlarging the eye part, correction for narrowing the nose width, and the like. Further, the image processing unit 6 corrects the color of the feature portion. For example, the image processing unit 6 performs color correction for increasing bluish color on the upper eyelid color and color correction for increasing redness on the cheek color. Thereby, since the effect of point makeup such as eye shadow and blusher is obtained, the appearance of a woman as a subject can be improved. Further, the image processing unit 6 performs color correction for increasing redness to the color of the lips. Thereby, the face color of the subject can be shown well.

  The control unit 7 performs overall control of the digital camera 1 according to a predetermined sequence program, and executes various calculations (AF, AE, etc.) necessary for imaging. The control unit 7 has functions such as a face detection unit 13 and a determination unit 14. The face detection unit 13 extracts a feature point from an image acquired by imaging or an image recorded on the recording medium 11, and detects a face, a face size, and the like. For example, the face detection unit 13 extracts a face by a feature point extraction process described in Japanese Patent Laid-Open No. 2001-16573. Examples of the feature points include eyebrow, eye, nose, and lip end points, face contour points, head apexes, and chin lower end points. Then, the face detection unit 13 specifies face position information.

  The determination unit 14 determines whether or not the face detected by the face detection unit 13 is blinking. Note that blinking means a state in which the subject in the image closes his eyes. FIG. 3A shows an example of an image with blinking on the subject, and FIG. 3B shows an example of an image without blinking. For example, the determination unit 14 detects the upper and lower eyelid lines of the eyes and measures the interval between the upper and lower eyelid lines. Then, the determination unit 14 determines that there is no blinking when the value of the interval is equal to or greater than a predetermined value. Further, the determination unit 14 determines whether or not the face detected by the face detection unit 13 is a smile. For example, as shown in JP-A-8-249453 and JP-A-10-255043, the determination unit 14 has six types of basic facial expressions of anger, disgust, fear, sadness, smile, and surprise as facial expression categories. Considering the above, the time-series image processing from the expressionless expression to each basic expression is performed, and it is determined whether or not it is a smile.

The display unit 8 displays various images under the control of the control unit 7. Various images displayed on the display unit 8 include a through image, a main image, an image recorded on the recording medium 11, a menu image, and the like. The operation unit 9 includes a release button 15, a cross key 16, and the like. The release button 15 is operated by the user during imaging. The cross key 16 is operated on the above menu image or the like. The state of the release button 15 and the cross key 16 is detected by the control unit 7, and a sequence based on the detected button and key states is executed. The recording I / F unit 10 includes a connector for connecting the recording medium 11. When the recording I / F unit 10 and the recording medium 11 are connected, data writing / reading is executed on the recording medium 11. The bus 12 connects the buffer memory 5, the image processing unit 6, the control unit 7, the display unit 8, and the recording I / F unit 10, thereby executing input / output of data and signals.

  The digital camera 1 performs blink detection and smile detection on the main image, and performs skin beautification on the main image only when there is no blink and a smile, and the main image subjected to skin beautification is recorded on the recording medium. 11 is recorded. On the other hand, when the face included in the main image has a blink or when it is not a smile, the face is recorded on the recording medium 11 as it is without performing skin beautification processing. The reason why the main image whose eyes are closed or the main image which is not a smile is recorded as it is is that these images are not preferable for the user and are likely to be deleted. In addition, although processing time of about 200 ms is required for blink detection and smile detection, the processing time of about 3 seconds can be shortened by not performing the skin beautification process on the main image with closed eyes or the main image that is not smiling. Can do. Therefore, since the time until the next imaging becomes possible is shortened, the possibility that a release time lag occurs can be reduced.

  FIG. 2 is a flowchart showing an operation at the time of imaging in the digital camera 1. For convenience, a scene in which one person is imaged will be described as an example.

  Step S101 is processing for starting the imaging mode. For example, the control unit 7 acquires a through image by controlling each unit.

  Step S102 is processing for determining whether or not the release button 15 has been half-pressed. If the release button 15 is pressed halfway (when the determination in step S102 is YES), the process proceeds to step S103. On the other hand, when the release button 15 is not half-pressed (when the determination in step S102 is NO), the process waits until the release button 15 is half-pressed.

  Step S103 is a process for locking AF and AE. The control unit 7 controls each unit to lock AF and AE.

  Step S104 is a process for determining whether or not the release button 15 is still half-pressed. When the release button 15 is continuously pressed halfway (when the determination in step S104 is YES), the process proceeds to step S105. On the other hand, if the release button 15 has not been pressed halfway (when the determination in step S104 is NO), the process returns to step S102 to determine whether the release button 15 has been pressed halfway.

  In step S105, it is determined whether or not the release button 15 has been fully pressed. If the release button 15 is fully pressed (when the determination in step S105 is YES), the process proceeds to step S106. On the other hand, when the release button 15 is not fully pressed (when the determination in step S105 is NO), the process returns to step S104, and it is determined whether or not the release button 15 is continuously pressed halfway.

  Step S106 is processing to acquire the main image. The control unit 7 controls each unit to acquire the main image. The image processing unit 6 performs white balance adjustment, color interpolation, gradation conversion processing, contour enhancement processing, and the like on the main image.

Step S107 is processing for determining whether or not a face has been detected. The face detection unit 13 detects a face from the main image acquired in step S106. When a face is detected (when the determination in step S107 is YES), the process proceeds to step S108. On the other hand, when the face is not detected (when the determination in step S107 is NO), the process proceeds to step S111 described later.

  Step S108 is processing for determining whether there is no blinking. The determination unit 14 determines whether or not the face detected by the face detection unit 13 in step S107 has any blinking. If there is no blinking (if the determination in step S108 is YES), the process proceeds to step S109. On the other hand, when there is blinking (when the determination in step S108 is NO), the process proceeds to step S111 described later.

  Step S109 is processing for determining whether or not the user is smiling. The determination unit 14 determines whether or not the face detected by the face detection unit 13 in step S107 is a smile. When it is a smile (when determination of step S109 becomes YES), it progresses to step S110. On the other hand, when it is not a smile (when determination of step S109 becomes NO), it progresses to step S111 mentioned later.

  Step S110 is a process for performing a skin beautification process on the main image. The image processing unit 6 performs skin beautification processing on the main image acquired in step S106.

  Step S111 is processing to record the main image. The control unit 7 records the main image acquired in step S106 or the main image subjected to skin beautification in step S110 on the recording medium 11. In addition, when recording the main image which performed the skin beautification process, the control part 7 records the information which shows the content of the skin beautification process in the Exif information (accessory information) of an image. Thereby, for example, if information indicating the content of the skin beautification process is displayed together with the image, the user can check what skin beautifying process has been performed at the time of reproduction of the main image. Note that the setting for skin beautification processing may be recorded as a separate file associated with the main image instead of recording as supplementary information.

  Note that the digital camera 1 according to the present embodiment can perform skin beautification processing during reproduction on a main image that has not been subjected to skin beautification processing, that is, a main image with blinking or a non-smiling main image. For example, the control unit 7 reads from the recording medium 11 the main image that has not been subjected to the skin beautifying process, using the accompanying information. Then, the control unit 7 displays a list of thumbnail images corresponding to the read main image on the display unit 8, and is subjected to skin beautification processing by the user's designation via the cross key 16 from the displayed list of thumbnail images. The selection of the main image is accepted. Thereafter, the control unit 7 displays a message such as “Do you want to beautify skin” on the display unit 8 together with the selected main image, and accepts the selection of whether or not to perform the beautification process (see FIG. 3). When the control unit 7 receives a selection for performing skin beautification processing, the control unit 7 controls the image processing unit 6 to perform skin beautification processing on the main image. When the control unit 7 receives an instruction to record the main image subjected to the skin beautification process, the control unit 7 records the main image on the recording medium 11.

  In a conventional digital camera that does not perform skin beautification processing at the time of image capture and performs skin beautification processing when an image is reproduced, first, selection of an image to be subjected to skin beautification processing is received from a user, and then skin beautification processing is performed on the selected image. Apply. In addition, in a digital camera configured not to perform skin beautification during playback but to perform skin beautification during imaging, when a setting for whether or not to perform skin beautification is received from the user in advance, Skin beautification processing is performed on an image obtained by imaging. However, there is a problem in that the operation for selecting an image during reproduction and setting during imaging is complicated. In order to avoid such a problem, a digital camera that always performs beautification processing on an image obtained by imaging can be considered. However, the skin beautification process described above is a complex process and takes about 3 seconds. For this reason, when it is desired to continuously capture images, the quickness and response are poor.

  Therefore, the digital camera 1 according to the present embodiment always enables the skin beautification process at the time of imaging, and performs the skin beautifying process on the main image when the face included in the main image has no blinking and is smiling. Therefore, according to the digital camera 1 of the present embodiment, it is possible to obtain a preferable image to which image processing is applied while reducing the possibility of occurrence of a release time lag. In addition, the digital camera 1 according to the present embodiment has good operability because the user does not have to specify whether or not to perform skin beautification processing on the main image via the cross key 16.

(Supplement of embodiment)
In the above embodiment, an example in which the skin beautification process is performed on the main image has been described, but the present invention is not limited thereto. For example, the image processing unit 6 may perform red-eye correction. As is well known, the red-eye phenomenon is a phenomenon in which light enters from a wide open pupil in the dark, and the black eye is photographed in red by reflection of the light into the venous membrane layer where innumerable capillaries run inside the eyeball. . The control unit 7 determines whether there is a red round region at a position corresponding to the face eye detected by the face detection unit 13. Then, if there is a red round area, the image processing unit 6 changes the color information of the area to, for example, black color information.

  The image processing unit 6 may correct the tooth color to white. Further, the image processing unit 6 may put a white glow that shines like light into the pupil. The shine shape may be a round shape or a star shape. Further, the image processing unit 6 may change the color of the pupil.

  Further, the image processing unit 6 specifies a dark portion or a highlight portion of the main image by image analysis as in D-Lighting (registered trademark), and adjusts the gradation of the image around the dark portion or the highlight portion. May be.

  Further, the image processing unit 6 may perform smile correction so as to approach a full smile. For example, the image processing unit 6 performs coordinate conversion and interpolation calculation so as to raise the mouth angle and lower the corner of the eye based on the position information of the pixels constituting the eye and mouth regions.

  In the above embodiment, whether or not the face state of the subject is good is determined by blink detection and smile detection, but the present invention is not limited to this. For example, the determination unit 14 performs known line-of-sight detection to determine whether the line of sight of the subject is facing the digital camera 1. When the control unit 7 determines that the line of sight of the subject is facing the digital camera 1, the control unit 7 may control the image processing unit 6 to perform skin beautification processing on the main image. Furthermore, exposure, focus state, camera shake, and the like may be taken into consideration in determining whether or not the face state is good. For example, the determination unit 14 determines that the exposure is appropriate, the in-focus state is good, and the face state is so good that there is no camera shake.

  In the above embodiment, an example is shown in which all the main images acquired in step S106 are recorded, but the present invention is not limited to this. For example, it is not necessary to record an image determined to have a blink in step S108 or an image determined not to smile in step S109.

  In step S <b> 101, the face detection unit 13 detects a face from the through image, and records the detected face position information in the buffer memory 5. In step S107, the face detection unit 13 may refer to the position information when detecting a face from the main image. Thereby, since the processing time of step S107 is shortened, the possibility of a release time lag can be further reduced.

DESCRIPTION OF SYMBOLS 1 ... Digital camera, 3 ... Image sensor, 6 ... Image processing part, 7 ... Control part, 13 ... Face detection part, 14 ... Determination part

Claims (6)

An imaging unit for acquiring an image;
A correction unit that performs a predetermined correction on the image acquired by the imaging unit;
A face detection unit for detecting the face of the subject from the image acquired by the imaging unit;
A determination unit that determines whether or not the state of the face detected by the face detection unit satisfies a predetermined condition;
For the image in which the face state is determined to satisfy the predetermined condition by the determination unit, the correction unit is controlled to perform the predetermined correction, and the face state is predetermined by the determination unit. A digital camera comprising: a control unit that controls to accept an instruction from a user as to whether or not the correction unit performs the predetermined correction for an image that is determined not to satisfy the condition. The digital camera according to claim 1, wherein
The digital camera according to claim 1, wherein the predetermined condition is that the face of the subject is not blinking. The digital camera according to claim 1 or 2,
The digital camera characterized in that the predetermined condition is that a face of the subject is a smile. 4. The digital camera according to claim 1, wherein the predetermined correction includes image processing including color tone correction, contrast correction, brightness correction, and adjustment of the facial feature portion. 5. A digital camera characterized by being a skin beautifying process including at least one of the image processing. The digital camera according to claim 4, wherein
The digital camera according to claim 1, wherein the adjustment of the characteristic portion in the face is an adjustment to make a tooth color white. The digital camera according to claim 4, wherein
The digital camera according to claim 1, wherein the adjustment of the characteristic portion of the face is an adjustment for changing a skin color of the subject.

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