KR101436838B1 - Method and apparatus for processing auto-focusing information, and digital photographing apparatus using thereof - Google Patents

Abstract

The present invention relates to an autofocusing information processing method and apparatus, and an autofocusing information processing method according to an embodiment of the present invention provides AF windows for a subject and a background, AF focusing is performed for each of the AF windows and whether or not the AF value of the subject in accordance with the auto focus operation is similar to the AF value of the background is displayed and the successful focusing operation is displayed according to the comparison result, have.

Auto focus, AF window, AF value

Description

TECHNICAL FIELD The present invention relates to an auto focusing information processing method and apparatus, and a digital photographing apparatus using the method.

The present invention relates to auto focusing, and more particularly, to a method and apparatus for processing auto focusing information and a digital photographing apparatus using the same.

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

Auto focus is a function of an optical system (camera) that automatically focuses on a specific object (subject). Most compact digital cameras use TTL contrast detection. In the case of a compact digital camera, it does not have a separate auto-focus sensor but analyzes the contrast of the image obtained through the CCD / CMOS image sensor and focuses it.

2. Description of the Related Art Generally, an autofocus (AF) method of adjusting the focus of a photographing lens of a digital camera is a method of photoelectrically converting a subject image by an image pickup device such as a CCD to generate an image signal, A method of calculating an AF evaluation value that is a contrast value of an image by extracting a high frequency component and detecting a focus position of the photographing lens based on the AF evaluation value is known.

In this method, an AF evaluation value is calculated at each position (focus position) of the focus lens while moving the focus lens in the direction of the optical axis, and a position where the AF evaluation value is maximized is detected as the in-focus position. 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.

However, in some cases, AF is completed and AF is performed through the above-described AF method, or the subject is not focused on the intended subject but the subject is focused in the background. In this case, when the edge component of the background is stronger than the center component of the subject, that is, the edge component of the person to be photographed, the blurred image appears with a high frequency. In such a situation where a false focus is generated, the AF value of the center AF window and the AF value of the surrounding AF window, that is, the area including the background image, substantially coincide with each other.

Conventional techniques for preventing such a false focus use a method of coloring an edge in a specific threshold value range, superimposing this on the photographic image data or enlarging an image of a specific area to display it to a user. However, these methods are not suitable for live view image processing which is displayed in real time because of excessive calculation amount in edge detection and coloring process, and there is a problem that a load is systematically generated.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems of the conventional art described above, and it is an object of the present invention to provide a subject AF window and a background AF window when the background edge component is stronger than an edge component of a center subject, And an object of the present invention is to provide an autofocusing information processing method and apparatus capable of performing an accurate focusing operation.

Another object of the present invention is to provide a digital photographing apparatus using the same.

According to an aspect of the present invention, there is provided an autofocusing information processing method comprising: providing AF windows for a subject and a background; Performing autofocusing on the AF window for the subject and the AF window for the background, respectively; Comparing whether the AF value of the subject is similar to the AF value of the background according to the auto focusing; And displaying the success or failure of auto focusing according to the comparison result.

Preferably, in the displaying step, when the AF value of the subject is similar to the AF value of the background, it indicates that the autofocusing has failed.

Preferably, after the AF window providing step, the step of displaying each of the AF windows may be characterized in that each of the displayed AF windows is selected by the user.

Preferably, the AF window providing step provides an AF window different according to at least one of a photographing composition, a size of a subject, a size of a fiducial point, and a photographing method, the respective windows for the subject and the background do.

Preferably, the size and position of the AF window are adjustable.

According to another aspect of the present invention, there is provided an autofocusing information processing apparatus including: an AF window providing unit for providing AF windows for a subject and a background; An autofocusing unit for performing autofocusing on the AF window for the subject and the AF window for the background; And a controller for comparing whether the AF value of the subject outputted from the autofocusing unit is similar to the AF value of the background, and displaying whether or not the autofocusing is successful according to the comparison result.

Preferably, the control unit controls the autofocusing unit to indicate that the autofocusing has failed if the AF value of the subject is similar to the AF value of the background.

Preferably, the AF window providing unit provides an AF window different according to at least one of a photographing composition, a size of a subject, a size of a point of interest, and a photographing method, the respective windows of the subject and the background .

According to another aspect of the present invention, there is provided a digital photographing apparatus for performing auto focusing, including: an AF window providing unit for providing AF windows for a subject and a background; An autofocusing unit for performing autofocusing on the AF window for the subject and the AF window for the background; And a controller for comparing whether the AF value of the subject output from the autofocusing unit is similar to the AF value of the background and displaying whether or not autofocus is successful according to the comparison result, , The digital signal processor displays each of the AF windows for the subject and the background on a live view screen. If the AF value of the subject is similar to the AF value of the background, The control unit controls the display unit to display the image.

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.

According to an embodiment of the present invention, there is provided an autofocusing information processing method comprising: providing respective AF windows for a subject and a background; performing autofocusing on an AF window for a subject and AF windows for a background; , It is possible to compare the AF value of the subject and the AF value of the background similar to each other and to indicate the success or failure of auto focusing according to the comparison result.

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 drive unit 11, an image pickup device 15, an image pickup device control unit 16, 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 driver 61, a scan driver 63, a display unit 65, and a digital signal processor (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 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. In the preferred embodiment of the present invention, the user can select the AF window for the subject and the AF window for the background through the operation unit 20, respectively, and can manipulate the size and shape of the AF window variously.

The digital camera 100 may further include 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 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). Further, in the preferred embodiment of the present invention, the display unit 65 displays the respective AF windows for the subject and the background on the live view screen. Also, it indicates to the user whether or not the autofocusing is successful according to the result of the autofocusing.

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, an AF window providing unit 73, and an autofocusing unit 74.

The control unit 71 controls the overall operation of the DSP 70. The control unit 71 compares whether the AF value of the subject output from the autofocusing unit 74 is similar to the AF value of the background and controls the user to indicate whether or not the autofocus is successful according to the comparison result. For example, if the background contains a large number of edge components, the AF value of the subject is similar to the AF value of the background. In this case, the user is informed that the autofocus has failed to prevent the focus from being misfocused. Also, the control unit 71 displays various AF window frames outputted from the AF window providing unit 73 to the user. And supplies information on the AF window region selected when the user selects the AF window for the displayed object and the background to the auto focusing unit 74. [

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 image signal processing unit 72 may perform the image signal processing on the image signal input in real-time in the live-view mode before photographing and the image signal input by the shutter-release signal. At this time, different video signal processing may be performed for each of the video signals.

The AF window providing unit 73 provides the AF window for the subject and the background, respectively, so that the user can select the AF window. The AF window can be provided differently depending on whether the user wants to capture an image, for example, a portrait image or a portrait image. Also, it can be variously provided depending on the size of the subject, the size of the point of attack, the shooting method, and the like. Here, the AF window will be described with reference to Figs. 3A to 3D.

Referring to Figures 3A-3D, various AF window frames are shown.

Fig. 3A is a horizontal cross-sectional view showing an AF window frame when a central subject is to be photographed. An AF window 310 for the subject and an AF window 320 for the background are shown. FIG. 3B is a vertical sectional view showing an AF window frame when a central subject is to be photographed. Similarly, an AF window 310 for the subject and an AF window 320 for the background are shown. Fig. 3C is a horizontal sectional view showing an AF window frame in a case where the size of the point of intersection is small. Similarly, an AF window 310 for the subject and an AF window 320 for the background are shown. FIG. 3D is a cross-sectional view showing an AF window frame in the case of self-photographing. Similarly, an AF window 310 for the subject and an AF window 320 for the background are shown.

The various AF window frames described with reference to Figures 3A-3D are illustrative and not restrictive, and may provide various AF window frames. In addition, the size and shape of the AF window of the subject or background may be manually adjusted by the user.

The autofocusing unit 74 performs AF processing on the AF window region for the subject and the background selected by the user from among the AF window for the subject and the background provided by the AF window providing unit 73. [ 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. Here, the autofocusing unit 74 outputs to the control unit 71 the AF value, which is the AF result value for the AF window region for the subject, and the AF value, which is the AF result value for the AF window region for the background .

4 is a flowchart illustrating a method of processing autofocus information according to another embodiment of the present invention.

Referring to FIG. 4, in step 400, an AF window is set up, which provides an AF window for the subject and background. In step 402, the AF window set on the live view screen is displayed. In step 404, it is determined whether there is a user input for the AF window for the displayed subject and background. That is, it is determined whether or not the user has selected the displayed AF window. If the user selects the AF window for a specific subject and the AF window for the specific background or the entire background, AF is performed for the AF window for the subject and the background selected by the user in step 406. In step 408, it is determined whether the AF result value of the subject AF window is similar to the AF value of the background window. Here, the criterion for judging similarity can be arbitrarily determined. As a result of the judgment in the step 408, in a similar case, there is a case where a lot of edge components are included in the background, and the background may be focused. Therefore, in this case, in step 414, the user is informed that the AF failure has occurred. On the other hand, if it is determined in step 408 that the AF value of the subject is not similar to the AF value of the background, the user is informed that the AF is successful in step 414.

Although the embodiments described above have been described with reference to a digital camera as an example of a digital photographing apparatus to which the present invention can be applied, the present invention is not limited thereto. Those skilled in the art will appreciate that the present invention is also applicable to camera phones, personal digital assistants (PDAs), and portable multimedia players (PMPs) with camera functions and strobe.

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 in the form of 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 100 according to an embodiment of the present invention.

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

3A to 3D are views for explaining a subject AF window and a background AF window according to another embodiment of the present invention.

4 is a flowchart illustrating a method of processing autofocus information according to another embodiment of the present invention.

Description of the Related Art

71: control unit 72: video signal processing unit

73: AF window providing unit 74: AF performing unit

Claims (10)

Providing respective AF windows for a subject and a background; Performing autofocusing on the AF window for the subject and the AF window for the background, respectively; Comparing whether the AF value of the subject is similar to the AF value of the background according to the auto focusing; And And displaying whether or not autofocusing is successful according to the comparison result. The method according to claim 1, In the displaying step, And when the AF value of the subject is similar to the AF value of the background, it indicates that the autofocusing has failed. 3. The method of claim 2, After the AF window providing step, And displaying each of the AF windows, Wherein each of the displayed AF windows is selected by the user. 3. The method of claim 2, The AF window providing step may include: Wherein each of the windows of the subject and the background provides different AF windows according to at least one of a photographing composition, a size of the subject, a size of a point of contact, and a photographing method. The method according to claim 1, Wherein the size and position of the AF window are adjustable. A recording medium on which a program for causing a computer to execute the method according to any one of claims 1 to 5 is recorded. An AF window providing unit for providing respective AF windows for a subject and a background; An autofocusing unit for performing autofocusing on the AF window for the subject and the AF window for the background; And And a control unit for comparing the AF value of the subject output from the autofocusing unit with an AF value of the background and controlling the display unit to indicate whether or not autofocus is successful according to the comparison result. 8. The method of claim 7, Wherein, And controls to display that the autofocusing has failed if the AF value of the subject is similar to the AF value of the background. 9. The method of claim 8, The AF window providing unit, Wherein each of the windows for the subject and the background provides different AF windows according to at least one of a photographing composition, a size of the subject, a size of a point of contact, and a photographing method. A digital photographing apparatus for performing auto focusing, comprising: An AF window providing unit for providing respective AF windows for a subject and a background; An autofocusing unit for performing autofocusing on the AF window for the subject and the AF window for the background; And And a controller for comparing the AF value of the subject output from the autofocusing unit with an AF value of the background and controlling the display of success or failure of auto focusing based on the comparison result, Wherein the digital signal processor comprises: Displaying the AF window of the subject and the background on a live view screen and displaying on the display unit that the AF focusing is failed when the AF value of the subject is similar to the AF value of the background, .

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