KR101436837B1 - Digital photographing apparatus for performing auto-focusing and method of controlling the same - Google Patents

Abstract

The present invention relates to a digital photographing apparatus for performing auto focusing and a control method thereof, and a method of controlling a digital photographing apparatus for performing auto focusing according to an embodiment of the present invention includes detecting a face region, The autofocusing is performed considering the movement of the image and the thermal information, so that even if there is a portrait, a picture, or a mannequin in the background, it is possible to photograph a person to be photographed by taking an AF.

Autofocusing, photographic equipment, thermal information

Description

TECHNICAL FIELD [0001] The present invention relates to a digital photographing apparatus for performing auto focusing, and a digital photographing apparatus for performing auto focusing,

The present invention relates to a digital photographing apparatus and a control method thereof, and more particularly to a digital photographing apparatus and a control method thereof for executing auto focusing.

Most digital cameras have a feature called AutoFocus that focuses on the subject you want to get a good picture.

Particularly, the function of the face-centered autofocus is to solve the problem that the person to be photographed is blurred because the person to be photographed is not in focus and another object such as a landscape is pitched. Such a face-centered autofocus function recognizes a face in a subject by image recognition processing and performs an autofocus processing so that the position of the recognized face is in focus.

However, the above-mentioned face-centered autofocus function is useful when photographing a person with real person's face and not a real person's face, for example, in a museum, exhibition hall or the like, The face in the background, not the person, is recognized as the face of the real person, and the focus can be adjusted by focusing the background on the real person's face without matching the focus on the face of the real person. It is recognized that the subject is photographed and the AF is fitted to the background rather than the person's face to be photographed, so that a blurred picture may be photographed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional art, and it is an object of the present invention to provide a digital photographing apparatus capable of detecting an actual human face to perform auto focusing when photographing a portrait, a figure, a mannequin, And to provide the above objects.

According to another aspect of the present invention, there is provided a control method of a digital photographing apparatus for performing autofocusing, the method including detecting a face region from an input image, detecting a motion of the image in the detected face region, ; If the motion of the image is not detected, controlling to detect thermal information about the face region; And performing autofocusing on the detected face region based on the sensed thermal information.

Preferably, the method is characterized in that autofocusing is performed only on the face region in which the thermal information exists.

Preferably, the method further comprises controlling the autofocusing on the face region in which the motion exists, when the motion of the image is detected, following the motion detection step.

Preferably, the input image includes an image other than a face image of a real person and a face image of a real person.

Preferably, the image other than the real person's face image includes a face image in a photograph, a mannequin, and a face image in a picture.

Preferably, the movement of the image is a movement of an eye, a nose, and a mouth of a face included in the face region.

According to another aspect of the present invention, there is provided a digital photographing apparatus for performing auto focusing, including: a face region detecting unit for detecting a face region from an input image; A motion detector for detecting a motion of an image in the detected face area; Controlling to detect thermal information on the face region when motion is not detected in the detected face region, and to perform autofocusing on the detected face region based on the sensed thermal information; And an autofocusing processor for performing autofocusing on the detected face area under the control of the controller.

Preferably, the apparatus further includes a thermal infrared sensor for sensing thermal information about the face region under the control of the controller.

Preferably, the controller is configured to perform autofocusing on the face region in which the motion exists when the motion is detected in the detected face region.

According to another aspect of the present invention, there is provided a computer-readable recording medium storing a program for causing a computer to execute the method according to another embodiment of the present invention.

A method of controlling a digital photographing apparatus for performing auto focusing according to an embodiment of the present invention includes detecting a face area and performing autofocusing considering motion and thermal information of the detected face area, Even if there is a portrait photograph, a picture, or a mannequin, there is an effect that the person who actually wants to photograph is photographed by performing AF.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts may be omitted so as not to disturb the gist of the present invention.

In addition, terms and words used in the following description and claims should not be construed to be limited to ordinary or dictionary meanings, but are to be construed in a manner consistent with the technical idea of the present invention As well as the concept.

1 is a block diagram of a digital camera according to an embodiment of the digital photographing apparatus of the present invention. 2 is a block diagram for explaining a digital signal processing unit of the digital camera.

1, the digital camera 100 includes an optical unit 10, an optical driving unit 11, an imaging device 15, an imaging device control unit 16, a thermal infrared sensor 17, an operation unit 20 A program storage unit 30, a buffer storage unit 40, a data storage unit 50, a display control unit 60, a data driving unit 61, a scan driving unit 63, a display unit 65, DSP, 70).

The optical section 10 receives an optical signal from a subject and provides it to the imaging element 13. [ The optical unit 10 may include at least one lens, such as a zoom lens for controlling the angle of view to be narrowed or widened according to the focal length, and a focus lens for focusing the subject. In addition, the optical unit 10 may further include a diaphragm for adjusting the amount of light.

The optical driver 11 controls the position of the lens, opening and closing of the diaphragm, and the like. The focus can be adjusted by moving the position of the lens. In addition, the amount of light can be adjusted by controlling the opening and closing of the diaphragm. The optical driving unit 11 can control the optical unit 10 according to a control signal automatically generated by a video signal input in real time or a control signal manually input by an operation of a user.

The optical signal transmitted through the optical section 10 reaches the light-receiving surface of the image pickup element 15 and forms an image of the subject. The image pickup device 15 may be a charge coupled device (CCD) or a complementary metal oxide semiconductor image sensor (CIS) for converting an optical signal into an electric signal. The sensitivity of the image pickup element 15 can be adjusted by the image pickup element controller 16. The image pickup element control unit 16 can also control the image pickup element 15 in accordance with a control signal automatically generated by the video signal inputted in real time or a control signal manually inputted by the user's operation.

The thermal infrared sensor 17 detects thermal information from a subject to be photographed and provides the thermal information to the DSP 70. Since the infrared ray sensor 17 emits infrared rays or heat inherent to all objects, such as a person or object, and the amount of infrared rays emitted by an object differs from the amount of infrared rays emitted by a person, can do. The thermal infrared ray sensor 17 is attached to the body of the digital camera 100 and includes an infrared ray detector, a heat ray detector, and a thermal equipment. In addition, the infrared ray sensor 17 may detect the infrared wavelength of a person and display the infrared ray in a color different from the surrounding color so that the user can easily identify the infrared ray. Also, the thermal infrared sensor 17 can be usefully used for AF or the like when the luminance is low.

The operation unit 20 is a place where a control signal from the outside of a user or the like can be input. The operation unit 20 includes a shutter-release button for inputting a shutter-release signal for exposing the image pickup device 15 to light for a predetermined period of time, a power button for inputting power, A wide angle-zoom button and a telephoto-zoom button for widening or narrowing the angle of view, a mode selection of a character input mode, a shooting mode, and a playback mode, a white balance setting function selection, and an exposure setting function selection. The operation unit 20 may have various types of buttons as described above, but the present invention is not limited thereto. The operation unit 20 may be implemented in any form such as a keyboard, a touch pad, a touch screen, and a remote controller.

The digital camera 100 includes a program storage unit 30 for storing programs such as an operating system and an application system for driving the digital camera, a buffer storage unit 30 for temporarily storing data or result data necessary for the operation, (40), and a data storage unit (50) for storing various information necessary for the program, including an image file including a video signal.

In addition, the digital camera 100 includes a display control unit 60 for controlling the display of the operation state of the digital camera 100 or the image information photographed by the digital camera 100, a data driving unit 60 for receiving display data input from the display control unit 60, And a display unit 65 for displaying a predetermined image according to a signal input from the scan driver 61, the scan driver 63, the data driver 61, and the scan driver 63. The display unit 65 may include a liquid crystal display panel (LCD), an organic light emitting display panel (OLED), and an electrophoretic display panel (EDD).

The digital camera 100 includes a DSP 70 that processes input video signals and controls the respective components according to the input video signals.

DSP 70 will be described with reference to FIG.

2, the DSP 70 includes a control unit 71, a video signal processing unit 72, a face region detection unit 73, a motion detection unit 74, and an auto focusing processing unit 75.

The image signal processing unit 72 converts a video signal inputted from the image pickup device 15 into a digital signal and outputs a gamma correction, a color filter array interpolation ), A color matrix, color correction, color enhancement, and the like. In addition, the video signal processing unit 72 can perform Auto White Balance or Auto Exposure algorithm when the function is set. Further, the size of the image data is adjusted using a scaler, and the image data is compressed to form an image file of a predetermined format. Conversely, the image file is decompressed. The video signal processor 72 may perform the above-described video signal processes on the video signal input in real-time in the live-view mode before photographing and the video signal input by the shutter-release signal. At this time, different video signal processing may be performed for each of the video signals.

The face region detection unit 73 detects the face region in the image subjected to the image processing through the image signal processing unit 72. The face region detection detects the position of a face in the image input through the image signal processing unit 72. [ The face area detection unit 73 compares the feature data of the face stored in advance with the input image data, recognizes whether or not there is face data in the input image, and if it is determined that there is face data, Is recognized. In the preferred embodiment of the present invention, since face detection is performed by comparing feature data of a face, the feature data extracted from the face of a photograph or a picture, the face of a mannequin, etc., Data can not be distinguished.

Referring to FIG. 3, there are two face images A and B in a scene to be photographed. Here, the face image A is a face image in a photograph, and the face image B is a face image of a real person. The face area detection unit 73 detects two face areas 300 and 310 in a scene to be photographed.

The motion detection unit 74 detects whether there is motion of the image in the detected face area. The motion detection unit 74 can detect a motion for a face area detected for a predetermined time, for example, 0.5 to 1 second. Referring to FIGS. 4A and 4B, the motion detector 74 detects whether there is motion in the range of the eyes, nose, mouth, and the like, with the face area as the center. In general, it is aimed to reduce the amount of computation by performing detection based on the region with the greatest movement in the face. The motion may be detected by detecting a difference image between frames before and after the image. When motion is detected in the detected face region, for example, in the case where motion is not detected in one face region among two detected face regions and motion is detected in the remaining face region, The control unit 71 provides the detected face region to the motion detection unit 71, and the control unit 71 can control to perform the auto focusing only on the detected region.

The control unit 71 controls the overall operation of the DSP 70. In the preferred embodiment of the present invention, when the motion detection unit 74 can not detect the motion in the face region detected by the motion detection unit 74, the control unit 71 determines the position of the face region detected by the face region detection unit 73 through the thermal infrared sensor So as to detect information. 5, when no motion is detected in both of the two face images 300 and 310, thermal information is detected for each of the images 300 and 310 to be photographed through the thermal infrared sensor 17 do. In this case, thermal information will not be sensed in the image 300 in the photograph, and thermal information will be sensed in the actual person's face image 310 as shown in FIG. When detecting the thermal information in the detected face area, the controller controls to perform auto focusing on the detected face area based on the sensed thermal information. The sensed thermal information is similar to the thermal information of the actual person stored in advance Thereby controlling whether or not the auto focusing is performed. This is because every object emits its own infrared rays or heat, and the amount of infrared light emitted by the real person is different from the amount of infrared light emitted from a region other than the actual person, including the face in the picture or picture. Thus, it is possible to distinguish the real person's face from the real person's face.

In addition, when the motion is detected in the detected face area, the control unit 71 controls to perform auto focusing on the face area in which the motion exists.

The auto focusing unit 75 determines the AF area as the face position of the recognized subject and executes AF processing. Generally, the AF processing can perform the AF processing by the contrast detection method or the AF processing by the pan focus. For example, the AF processing by the contrast detection method moves the focus lens to the lens position where the contrast value of the AF area determined to execute AF is the highest. That is, the focus lens is moved, the contrast of the CCD at that time is converted into an electric signal, the waveform is analyzed, and the focus lens is aligned with the lens position where the high frequency component is the largest.

6 is a flowchart illustrating a method of controlling a digital photographing apparatus for performing auto focusing according to another embodiment of the present invention.

Referring to FIG. 6, in step 600, an image of a subject to be photographed is input. In step 602, a face area to be photographed is detected in the input image. In step 604, the motion of the image is detected in the detected face region, and the motion of the image can be determined based on whether the eye, nose, mouth, and the like move around the face region. Here, when there is motion of the image, it can be judged that it is the face image of the real person.

If it is determined in step 606 that there is motion of the image, the process proceeds to step 608 to execute AF on the face area in which the motion is detected, and when the shutter release signal is input in step 614, the imaging is performed.

If it is determined in step 606 that no motion is detected in all of the detected face areas, in step 610, thermal information about the detected face area is sensed, which may use a thermal infrared sensor attached to the digital photographing apparatus. If no thermal information is detected, the flow advances to step 614 to perform AF set as default, and a photograph is taken when a shutter release signal is input. If it is determined in step 612 that the thermal information is detected, AF is performed on the face area in which the thermal information is detected in step 614. When the shutter release signal is inputted in step 614, a photograph is taken.

Meanwhile, the present invention can be embodied in computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored.

Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device and the like, and also a carrier wave (for example, transmission via the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the present invention can be easily deduced by programmers skilled in the art to which the present invention belongs.

The present invention has been described above with reference to preferred embodiments. It will be understood by those skilled in the art that the present invention may be embodied in various other forms without departing from the spirit or essential characteristics thereof. Therefore, the above-described embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

1 is a schematic block diagram of a digital photographing apparatus according to an embodiment of the present invention.

2 is a specific block diagram of the DSP 70 shown in FIG.

FIGS. 3 to 5 are diagrams for explaining an auto focusing operation by distinguishing a human face and a real human face in a photograph according to another embodiment of the present invention.

6 is a flowchart for explaining a method of controlling a digital photographing apparatus for performing auto focusing according to another embodiment of the present invention.

Description of the Related Art

71: control unit 72: video signal processing unit

73: face area detecting unit 74: motion detecting unit

75: auto focusing processing section

Claims (10)

Detecting a face region from an input image; Detecting motion of the image in the detected face region; If the motion of the image is not detected, controlling to detect thermal information about the face region; And And performing autofocusing on the detected face area based on the sensed heat information. The method according to claim 1, Wherein the auto focusing step comprises: Wherein the automatic focusing is performed only on the face area in which the thermal information exists. The method according to claim 1, After the motion detection step, Further comprising the step of, when the motion of the image is detected, controlling to perform autofocusing on the face region in which the motion exists. The method according to claim 1, The input image may include: A face image of a real person and an image that is not a face image of a real person. 5. The method of claim 4, The image, which is not the face image of the real person, A face image in a photograph, a mannequin, and a face image in a picture. The method according to claim 1, The motion of the image is, Wherein the movement of the face, the eye, the nose, and the mouth of the face included in the face area is performed. A recording medium on which a program for causing a computer to execute the method according to any one of claims 1 to 6 is recorded. A face region detecting unit for detecting a face region from an input image; A motion detector for detecting a motion of an image in the detected face area; Controlling to detect thermal information on the face region when motion is not detected in the detected face region, and to perform autofocusing on the detected face region based on the sensed thermal information; And And an autofocus processing unit that performs autofocusing on the detected face area under the control of the control unit. 9. The method of claim 8, Further comprising a thermal infrared sensor for sensing thermal information on the face region under the control of the control unit. 9. The method of claim 8, Wherein, And controls to perform autofocusing on the face area in which the motion exists if motion is detected in the detected face area.

Images