KR101362766B1 - Method of controlling digital image processing apparatus which display the assistant image in the dark and digital image processing apparatus adopting the same - Google Patents

Abstract

The present invention relates to a digital image processing apparatus and a control method thereof for displaying an auxiliary screen image in a dark place, the method comprising the steps of: (a) calculating an average luminance of an image input to an image sensing element; (b) Capturing an auxiliary screen image when the average brightness is smaller than a reference brightness, and displaying the sub screen image when the input brightness is smaller than the reference brightness. So that the subject can be photographed in a desired composition.

Digital image processing apparatus, average luminance

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method of a digital image processing apparatus for displaying an auxiliary screen image in a dark place and a digital image processing apparatus employing the same,

The present invention relates to a digital image processing apparatus and a control method thereof, and more particularly, to a digital image processing apparatus and a control method thereof for displaying an auxiliary screen image in a dark place.

Recently, the digital image processing apparatus provided supports a live-view mode. The live view mode means that the image of a subject that the user wants to capture with the digital image processing device appears on the display screen in real time.

With this live view function, the digital image processing device can capture clear images by using the flash even in the dark. Also, the auto focus (AF) function and auto exposure (AE) Function and the like, it is possible to automatically adjust the exposure setting and focusing without performing a user operation, thereby capturing an image of good quality.

However, in a dark place, there is a problem that the live view image displayed on the display screen of the digital image processing apparatus is not clear. This is because in the dark, the imaging device can not detect a sufficient amount of light from the object. Therefore, when capturing an image of a subject using a digital image processing apparatus in a dark place, the degree of focusing or exposure can be controlled by the AF function and the AE function, but the subject can not be arranged at a desired position in the image There is a problem that the image can not be captured in a desired composition.

An object of the present invention is to provide a control method and apparatus for a digital image processing apparatus for displaying an auxiliary screen image so that a user can capture an image of a subject in a dark place.

According to an aspect of the present invention, there is provided a method of driving an image pickup device, comprising the steps of: (a) calculating an average luminance of an image input to an image pickup device; (b) Capturing an auxiliary screen image when the brightness of the sub screen image is smaller than the brightness; and (c) displaying the sub screen image.

In the present invention, in the step (c), the sub screen image may be displayed in a translucent manner.

In the present invention, in the step (c), the sub screen image may be displayed on a part of the display screen.

In the present invention, when the automatic focusing function is performed by inputting a signal from the first shutter button in the step (b), any one of the images input in the process of performing the automatic focusing function Can be captured as the sub screen image.

In the present invention, in the step (b), an image input after completion of the automatic focusing function may be captured as the sub-screen image.

Also, in the present invention, in the step (b), the auxiliary screen image may be captured using auxiliary light.

According to a second aspect of the present invention, there is provided a digital image processing apparatus including a control unit, wherein the control unit is a digital image processing apparatus employing the control method of the present invention.

In this way, when the average brightness of the image of the subject input to the image pickup device is lower than the predetermined reference brightness, the image of the subject is captured when the first shutter button is pressed and the sub-screen image is generated and displayed. . ≪ / RTI >

Hereinafter, preferred embodiments will be described in more detail with reference to FIGS. 1 to 8. FIG.

1 (a) and 1 (b) are diagrams showing the outline of a digital image processing apparatus according to an embodiment of the present invention.

1 (a) and 1 (b), a digital image processing apparatus according to the present invention includes a shutter button 110, a power button 120, a flash 130, a supplementary light 140, And a wide angle zoom button 160w, a telephoto zoom button 160t, a function button 170 and a display screen 180 on the back side.

The shutter button 110 is opened and closed to expose the CCD or the film to light for a predetermined time, and the image is recorded on the CCD by properly exposing the subject in cooperation with the aperture (not shown).

The shutter button 110 generates first and second image pickup signals by a user input. When a signal is input from the first shutter button as a half-shutter signal, the digital image processing apparatus focuses and adjusts the amount of light. At this time, the display screen 180 is lit green. The focusing function may be automatically performed by the AF function, and the amount of the light may be automatically adjusted by the AE function. When the signal is input through the first shutter button and the amount of light is adjusted, a signal from the second shutter button is input as a full shutter signal to photograph the image.

The power button 120 is input for supplying power to the digital image processing apparatus and operating it.

The flash 130 illuminates bright light instantly when shooting in a dark place. The flash mode includes automatic flash, forced flash, prohibited flash, red-eye reduction, and slow synchro flash. It is possible to use the flash 130 if it is not easy to generate the sub screen image according to the present invention using the auxiliary light 140 alone.

The auxiliary light 140 supplies light to the subject so that the digital image processing apparatus automatically catches the focus quickly and accurately at the time of lack of light amount or at night shooting. The auxiliary light 140 may operate when the shutter button 110 has a signal input by the first shutter button. The AF function can be easily performed by the auxiliary light 140. [ Further, it facilitates to generate the sub-screen image according to the present invention by the auxiliary light 140. [

The lens unit 150 receives light from an external light source and processes the image.

The wide angle-zoom button 160w or the tele-zoom button 160t widens the angle of view or narrows the angle of view depending on the input, and is input particularly when the size of the selected exposure area is to be changed. When the wide angle-zoom button 160w is input, the size of the selected exposure area is reduced, and when the telephoto-zoom button 160t is input, the size of the selected exposure area is increased.

The function button 170 includes a total of five buttons including an up button, a down button, a left button, a right button, and a menu / OK button. The function buttons 170 are input to execute various menus related to the operation of the digital image processing apparatus, and the respective keys can also be used as shortcut keys.

The display screen 180 displays a UI and a preview screen provided according to the operation of the subject, the function button 170 by the user, and the like.

Of course, the camera shown in FIG. 1 (a) and FIG. 1 (b) is merely an embodiment of the digital image processing apparatus according to the present invention, and the digital image processing apparatus according to the present invention may be a camcorder other than a camera. In addition, even if the digital image processing apparatus according to the present invention is a camera, it may be a lens interchangeable camera having a shape different from that shown in Figs. 1A and 1B or a single lens reflex (SLR) It is a matter of course that various modifications are possible.

2 is a block diagram illustrating an internal configuration of a digital image processing apparatus according to an embodiment of the present invention.

2, the digital image processing apparatus according to the present invention includes a control unit 210, a video capturing unit 220, a user input unit 230, a storage unit 240, and a display screen 250, The storage unit 240 may include a first storage unit 241, a second storage unit 242, and a third storage unit 244. The first storage unit 241, the second storage unit 242, And a storage unit 243.

The control unit 210 controls the overall operation of the digital image processing apparatus 200. The control unit 210 receives an image of a subject from the image capturing unit 210 and calculates an average brightness of the input image, .

The controller 210 may include a luminance calculator 211 and an auxiliary screen image generator 212.

The luminance calculator 211 calculates an average luminance of an image of a subject input to an image sensor included in a digital image processing apparatus according to an exemplary embodiment of the present invention.

When the average luminance of the image calculated by the luminance calculation unit is smaller than a predetermined reference luminance, the sub-picture image generation unit 212 captures an image of the subject when there is an input of a signal by the first shutter button from the user And generates an auxiliary screen image.

The image capturing unit 220 may include a lens unit 150, a charge coupled device (CCD) as an image sensing device, an analogue digital converter (ADC), and the like, which capture an image of a subject and generate a digital signal.

The user input unit 230 indicates a series of keys that are input to operate the digital image processing apparatus 100. A shutter button 110, a wide angle-zoom button 160w, a telephoto-zoom button 160t, a function button 170, and the like shown in FIG. 1 (b) have.

The storage unit 240 may include a first storage unit 241, a second storage unit 242, and a third storage unit 243.

The first storage unit 241 may store user setting data related to shooting conditions and the like. In addition, an algorithm used by the controller 210 to control the digital image processing apparatus may be stored. An algorithm for calculating an average brightness of an image input to the image pickup device by the brightness calculating unit 211 and an algorithm for generating an auxiliary screen image by the sub screen image generating unit 212 may be stored. As the first storage unit 141, an electrically erasable and programmable read only memory (EEPROM) may be used.

The second storage unit 242 temporarily stores data, and temporarily stores the digital video signal from the digital signal processing unit. The second storage unit 242 may be a dynamic random access memory (DRAM) or the like.

The third storage unit 243 may store the images captured by the image capturing unit 220, the image capturing information of the images, and the sub-screen image. As the third storage unit 243, a memory card or the like may be used, and the third storage unit 243 may be a built-in or removable external type.

The display screen 250 displays an image of a subject in real time in the live view mode and displays an auxiliary screen image when the average brightness of the subject image is low in a dark place.

As described above, when the average brightness of the image of the subject input to the image pickup device is lower than the predetermined reference brightness, the user can capture the image of the desired subject by providing the sub-screen image.

3 is a view showing an image pickup device according to an embodiment of the present invention.

3, a method of calculating the average brightness of an image of a subject input to an image pickup device will be described. The image pickup device 300 is divided into 14 patches, that is, 14 patches, that is, 140 patches, and then the brightness of each patch is calculated. The method of calculating the luminance of each patch can be expressed by the following equation (1).

The Y / patch means an average luminance per patch, and R means red, G means green, and B means blue. Therefore, ΣR means the total number of red pixels, ΣG means the total number of green pixels, and ΣB means the total number of blue pixels. The obtained average luminance value can be calculated by the following equation (2) in order to calculate the average luminance value of the entire image sensing device by the average luminance value for one patch.

Y is the average luminance of the entire image,? (Y / patch) is the total sum of average luminance per patch, and? P is the total number of patches. According to the above example, since the total number of patches is 140, the denominator will be 140.

If the average brightness of the entire image is lower than the predetermined reference brightness, for example, the reference brightness is 5LV, if the average brightness of the entire image is lower than the 5LV as described above, And if the average brightness of the entire image is equal to or higher than the reference brightness of 5LV, a general live view image will be displayed. Even when the sub screen image is generated and displayed, the live view image will be displayed together.

The above-described method of calculating the average luminance or the mathematical expression is an example and is not necessarily limited to the above-described method. It is also possible to calculate the entire image pickup device as one area without dividing the image into a plurality of patches. Further, the 5LV described with reference brightness is an exemplary value and may be set to another value.

4 is a flowchart illustrating a method of displaying an auxiliary screen image by a method of controlling a digital image processing apparatus according to an embodiment of the present invention.

4, when the user turns on the digital image processing apparatus to capture an image of a subject and the digital image processing apparatus displays the live view image, the image of the subject is input to the image capturing element through the image capturing unit The average luminance of the image of the input subject is calculated (step 401).

When the user half-presses the shutter button to focus on the subject, a signal from the first shutter button is input (step 402).

AF and AE functions are executed by inputting a signal from the first shutter button. In step 403, the digital image processing apparatus compares whether the average brightness of the subject image has a value lower than a predetermined reference brightness.

If it is determined that the average luminance of the image of the subject has a value lower than the reference luminance by the comparison, the image of the subject is captured using the auxiliary light used in performing the AF and AE functions in operation 404. Generally, in order to display a live view image in a shooting mode, an image of a subject is successively input to an image pickup device, and one of the input images is captured as a sub-screen image.

In operation 405, when an image of a subject is captured, a sub-screen image is generated using the captured image of the subject.

The controller combines the sub-screen image with the live-view image and displays it on the display screen (step 406).

As a method of displaying the auxiliary screen image on the display screen, there is a method of displaying the auxiliary screen image in a semi-transparent manner and superimposing it on the live view image. In addition, the auxiliary screen image is resized to a size smaller than the display screen A method of displaying the image on a part of the display screen is also possible.

If the average brightness of the image of the subject is higher than the reference brightness, the live view image is continuously displayed in the same manner as in the conventional digital image processing apparatus (step 407).

5 is a flowchart illustrating a method of displaying an auxiliary screen image by a method of controlling a digital image processing apparatus according to an embodiment of the present invention.

Referring to FIG. 5, the flowchart of FIG. 5 illustrates an operation process of the digital image processing apparatus when the average luminance of an image of a subject is lower than a reference luminance. If the average luminance of the image of the subject is lower than the reference luminance in the dark place of the subject, if the user inputs a signal from the first shutter button (step 501), the control unit of the digital image processing apparatus operates the auxiliary light to illuminate the subject with auxiliary light (Step 502). If it is not easy to capture the sub screen image by the auxiliary light, it is also possible to further illuminate the flash on the subject.

If the auxiliary light is illuminated, the AF function is executed in the digital image processing apparatus having the AF function (step 503). When the AF function is executed, the control unit drives the motor connected to the lens so that the image of the subject is in focus, and selects the most focused image among the images of the subject input in real time through the lens. The method of selecting an image of the focused object can be performed by a known algorithm. It is possible to use any one of the images of the subject input through the lens in real time, that is, the images input in the process of performing the AF function, as the sub-screen image.

In particular, after executing the AF function, the control unit may capture an image of the focused object so that the user can easily determine the composition of the subject (Step 504). It is possible to capture the image of the subject before executing the AF function. However, after adjusting the focus by executing the AF function, that is, capturing the image of the subject after the execution of the AF function is completed, You can do it.

After capturing an image of a subject, a sub-screen image is generated using the captured image in step 505.

The generated sub-screen image is processed in a semi-transparent manner to be superimposed on the live view image and displayed on the display screen in step 506.

In this way, when the average brightness of the image of the subject input to the image pickup device is lower than the predetermined reference brightness, the image of the subject is captured when the first shutter button is pressed and the sub-screen image is generated and displayed. . ≪ / RTI >

FIG. 6 is a view illustrating a display screen displaying a semitransparent auxiliary screen image according to an embodiment of the present invention.

Referring to FIG. 6, in a dark place, the appearance of the subject is not clearly displayed on the display screen even by the live view image (see 600). When a signal from the first shutter button is input, a small amount of light is emitted to the subject by the auxiliary light. Thus, when a signal from the first shutter button is input, an image of the subject is captured to generate a sub-screen image (see 601). According to the present invention, the sub-screen image is synthesized with the live view image so that the user can guess the position of the subject, thereby facilitating the composition of the image (see 602).

7 is a flowchart illustrating a method of displaying an auxiliary screen image by a method of controlling a digital image processing apparatus according to an embodiment of the present invention. In the description of FIG. 7, differences from FIG. 5 will be mainly described.

Referring to FIG. 7, when the AF function is executed by inputting a signal from the first shutter button, the image capturing unit captures an image of a subject to generate a sub-screen image (steps 701 to 705).

The size of the sub screen image is adjusted to display the generated sub screen image in a partial area of the display screen, the synthesized sub screen image is synthesized with the live view image and displayed on the display screen (step 706) .

When the average brightness of the image of the subject input to the image pickup device is lower than the predetermined reference brightness, when the signal from the first shutter button is input, the image of the subject is captured and the sub-screen image is generated and displayed. Thereby making it possible to capture an image of a subject.

FIG. 8 is a view illustrating a screen in which a sub-screen image according to an embodiment of the present invention is displayed on a partial area of a display screen. In the description of FIG. 8, the difference between FIG. 6 and FIG. 6 will be mainly described.

Referring to FIG. 8, in a dark place, the appearance of the subject is not clearly displayed on the display screen even by the live view image (see 800). When a signal from the first shutter button is input, a small amount of light is emitted to the subject by the auxiliary light. Thus, an image of the subject is captured when the first shutter button is pressed (see 801). According to the present invention, after adjusting the size of the sub screen image to be displayed on a partial area of the display screen, the sub screen image whose size is adjusted is synthesized with the live view image so that the user can guess the position of the subject So that it is easy to compose the image (see 602). In this figure, the size-adjusted sub screen image is located at the lower left of the display screen, but the position for displaying the sub screen image is not limited to the above position.

The foregoing description and drawings are merely illustrative of the present invention and are used for the purpose of illustrating the present invention only and not for limiting the scope of the present invention described in the claims or the claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made without departing from the spirit of the invention. Therefore, the technical protection scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

1 (a) and 1 (b) are diagrams showing the outline of a digital image processing apparatus according to an embodiment of the present invention.

2 is a block diagram illustrating an internal configuration of a digital image processing apparatus according to an embodiment of the present invention.

3 is a view showing an image pickup device according to an embodiment of the present invention.

4 is a flowchart illustrating a method of displaying an auxiliary screen image according to a method of controlling a digital image processing apparatus according to an exemplary embodiment of the present invention.

5 is a flowchart illustrating a method of displaying an auxiliary screen image by a method of controlling a digital image processing apparatus according to an embodiment of the present invention.

FIG. 6 is a view illustrating a display screen displaying a semitransparent auxiliary screen image according to an embodiment of the present invention.

7 is a flowchart illustrating a method of displaying an auxiliary screen image by a method of controlling a digital image processing apparatus according to an embodiment of the present invention.

FIG. 8 is a view illustrating a screen in which a sub-screen image according to an embodiment of the present invention is displayed on a partial area of a display screen.

Claims (7)

(a) calculating an average luminance of an image input to the image pickup device; (b) capturing an auxiliary screen image when a signal from the first shutter button is input and the average luminance is smaller than a reference luminance; And (c) displaying the sub screen image. The method according to claim 1, wherein in the step (c) And displaying the sub screen image in a translucent manner. The method according to claim 1, wherein in the step (c) And displaying the sub screen image on a partial area of the display screen. The method of claim 1, wherein, in step (b) When the automatic focusing function is performed by inputting a signal from the first shutter button, And capturing any one of the input images as the sub-screen image in the process of performing the automatic focusing function. 5. The method of claim 4, wherein in step (b) And capturing the input image after the completion of the automatic focusing function as the sub-screen image. The method of claim 1, wherein, in step (b) And capturing the auxiliary screen image using the auxiliary light. A digital image processing apparatus having a control unit, Wherein the control unit employs the control method according to any one of claims 1 to 6.

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