KR20100075166A - Apparatus for processing digital image and method for controlling thereof - Google Patents

Abstract

PURPOSE: An apparatus for processing a digital image and a method for controlling the same are provided to select a zoom adjustment method according to the timing of zoom bracketing adjustment. CONSTITUTION: An input image is inputted(S420), and a face region is detected from the input image(S430). A focus is adjusted for the input image(S440), and the input image is captured(S450). It is judged whether or not the face region is detected from the input image(S460), and a central region is set up in the input image(S470). Zoom bracketing photographing is performed without adjustment of a focus for the central region(S500).

Description

Apparatus for processing digital image and method for controlling Technical Field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image processing apparatus and a control method thereof, and more particularly, to a digital image processing apparatus having a zoom function capable of photographing a distant subject in close proximity and a control method thereof.

Typically, the digital image processing apparatus includes all devices that process images such as a digital camera, a personal digital assistant (PDA), a phone camera, a PC camera, or use an image recognition sensor.

The digital image processing apparatus may image an image received through an image pickup device by a digital signal processor, compress the image, generate an image file, and store the image file in a memory.

In addition, the digital image processing apparatus may display and display an image of an image file received through an imaging device or stored in a storage medium on a display device such as a liquid crystal display (LCD).

Typically, the digital image processing apparatus may have a zoom function. In this case, the zoom function may include a wide zoom function and a tele zoom function. The wide zoom function allows the field of view to be widened and the selected exposure area to be large. By the tele zoom function, the angle of view can be narrowed and the selected exposure area can be made small.

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital image processing apparatus capable of shortening the time required for auto focus adjustment by selecting an appropriate zoom adjustment method according to the timing of zoom bracketing adjustment, and a control method thereof. do.

The present invention, the step of receiving an input image; Detecting a face region in the input image; Adjusting a focus on the input image; Photographing the input image; Setting a center area in the input image; And performing zoom bracketing imaging on the center area without adjusting focus.

The step of setting the center area comprises: determining whether a face area is detected in the input image; setting the face area as the center area when the face area is detected in the input image; and The method may include setting a focus area for adjusting the focus as the center area when the face area is not detected in the input image.

When a plurality of face areas are detected, a specified face may be recognized, and the recognized face area may be set as the center area.

The step of performing the zoom bracketing photographing includes: determining a current zoom level, performing zoom bracketing photography by digital zoom-in when the current zoom level is a set wide-angle end, and the current When the zoom level is set to the telephoto end, the method may include performing zoom bracketing imaging by optical zoom out.

The performing of the zoom bracketing photographing may include moving the current zoom level to the wide-angle end when the current zoom level is an intermediate level close to the wide-angle end, and wherein the current zoom level is the telephoto end. The method may further include moving the current zoom level to the telephoto end at the intermediate level close to, and performing focus adjustment at the current zoom level.

By zooming in on the current zoom level until the set zoom limit is reached, zoom bracketing photography can be performed by digital zoom-in.

The digital zoom-in may be performed by fixing a position of a center point of the center area in the input image.

The step of performing the zoom bracketing photographing by the digital zoom-in comprises: generating a zoom-in image by digitally zooming in on a current zoom level, determining whether the center region is cut off, and cutting the center region When it is determined that the center area is not cut, the method may include moving the position of the center point to generate the zoom-in image, and photographing the zoom-in image.

The optical bracketing may be performed by optical zooming out with respect to the current zoom level until the set zoom limit is reached.

The step of performing zoom bracketing photographing by the optical zoom-out comprises: optically zooming out a current zoom level, receiving a zoom-out image by the zoom level by the zoom-out, and the zoom-out image. It may have a step of photographing.

Performing zoom bracketing photographing by the optical zoom-out may include detecting a face region in the zoom-out image when the face region is detected in the input image, and detecting the face region in the zoom-out image. If detected, the method may include photographing the zoom-out image.

Another aspect of the invention, the image input unit for receiving an input image; A zoom adjuster for adjusting a zoom level of the input image; A focus adjuster for adjusting a focus of the input image; And a controller configured to set a center region in the input image and to perform zoom bracketing photographing without adjusting focus on the center region.

Photographing may be performed by adjusting a focus on the input image.

When the face region is detected from the input image, the face region is set as the center region when the face region is detected from the input image, and the focus is adjusted when the face region is not detected from the input image. A focus area may be set as the center area.

When a plurality of face areas are detected, a specified face may be recognized, and the recognized face area may be set as the center area.

When the current zoom level is a wide-angle end set, zoom bracketing shooting may be performed by digital zoom-in, and when the current zoom level is set telephoto end, zoom bracketing shooting may be performed by optical zoom-out. .

The current zoom level is moved to the wide angle end when the current zoom level is an intermediate level close to the wide end, and the current zoom level when the current zoom level is an intermediate level close to the telephoto end. Move to the telephoto end and perform focus adjustment at the current zoom level.

The digital zoom-in may be performed by fixing a position of a center point of the center area in the input image.

A digital zoom-in image is generated by digital zooming in on the current zoom level until the set zoom limit is reached, and when the center region is determined to be cut, the position of the center point is moved until the center region is not cut. The zoom-in image may be photographed.

When the zoom out image is input by optically zooming out the current zoom level until the set zoom limit is reached, the face region is detected from the input image, and the face region is detected from the zoom out image. Photographing of the zoom-out image may be performed.

According to the digital image processing apparatus and the control method thereof according to the present invention, the time required for the auto focus adjustment can be shortened by selecting an appropriate zoom adjustment method according to the timing of the zoom bracketing adjustment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a rear view of a digital camera 100 which is an embodiment of a digital image processing apparatus according to the present invention.

Referring to the drawings, on the back of the digital camera 100, the direction button 21, the menu-OK button 22, the wide angle (Zoom) button (W), the telephoto (Zoom) ) Button T, the display panel 25 and the like.

The direction button 21 may include four buttons, an up button 21a, a down button 21b, a left button 21c, and a right button 21d. The direction button 21 and the menu-OK button 22 are keys for executing various menus relating to the operation of the digital image processing apparatus such as a digital camera.

The wide-angle zoom button W or the tele-zoom button T has a wider angle of view or a narrower angle of view depending on its input. In particular, it may be used to change the size of the selected exposure area. In this case, when the wide-zoom button W is input, the size of the selected exposure area increases, and when the tele-zoom button T is input, the size of the selected exposure area may decrease.

As the display panel 25, an image display device such as a liquid crystal display (LCD) may be used. The display panel 25 may be included in the display unit 350 of FIG. 3, in which an input image input by the set zoom level is displayed.

Meanwhile, a shutter release button 26, a flash (not shown), a power switch 28, and a lens unit (not shown) may be provided on the front or top surface of the digital camera 100. In addition, the front and rear of the digital camera 100 may be provided with an objective lens and an eyepiece of the viewfinder 27.

The shutter release button 26 and the power switch 28 may be included in a user manipulation unit (360 of FIG. 3) for inputting items to be manipulated by the user from the outside.

The shutter release button 26 is opened and closed to expose the film or an image pickup device such as a charge coupled device (CCD) for a predetermined time. In addition, the shutter release button records an image on the image pickup device by properly exposing a subject in association with an aperture (not shown).

On the other hand, the shutter release button 26 can be pressed in two stages. When the shutter release button 26 is pressed in one end, the first signal S1 may be generated, and when the shutter release button 26 is pressed in one step, the second signal S2 may be generated. The shooting preparation setting may be performed by the first signal S1, and the shooting operation may be performed by the second signal S2.

As an embodiment of a digital image processing apparatus to which the present invention can be applied, a digital camera, a control apparatus, and a control method thereof are disclosed in US Patent Application Publication No. 2004/0130650 (name: automatic using a secondary function of the camera). Method of automatically focusing using a quadratic function in camera.

Matters relating to the digital camera, the control apparatus, and the control method disclosed in the above-mentioned US application will be included in the present specification, the detailed description thereof will be omitted.

2 is a block diagram of the control device 200 of the digital image processing apparatus according to the preferred embodiment of the present invention. The control device 200 of the digital image processing apparatus may be mounted in the digital camera 100 of FIG. 1.

Referring to the drawing, an optical system OPS including a lens unit and a filter unit optically processes light from a subject. The lens unit of the optical system OPS includes a zoom lens, a focus lens, and a compensation lens. When the user presses the wide-angle zoom button W or the tele-zoom button T included in the user input unit INP, a signal corresponding thereto is input to the microcontroller 212.

Accordingly, as the microcontroller 212 controls the lens driver 210, the zoom motor M _Z is driven to move the zoom lens. That is, when the wide-zoom button W is pressed, the focal length of the zoom lens is shortened to widen the angle of view, and when the tele-zoom button T is pressed, the focal length of the zoom lens becomes long and the angle of view is narrowed.

In this case, the zoom control may be performed by the zoom adjusting unit 380 of FIG. 3. The zoom adjusting unit 380 may include a zoom lens and a zoom driver. The zoom driver may include a zoom motor M _z and a lens driver 210 to drive the zoom lens to move the position of the zoom lens.

On the other hand, in the auto focusing mode, the main controller embedded in the digital signal processor 207 controls the lens driver 210 through the microcontroller 212, and thus the focus motor M _F is driven. do. That is, the focus lens is moved to a position where the sharpest picture is obtained by driving the focus motor M _F.

The auto focus mode may be performed according to the first signal S1 generated by pressing the shutter release button 26 of FIG. 1 input through the user input unit INP. At this time, the plurality of images are input while the position of the focus lens is moved along the optical axis, and the position of the focus lens which obtains the clearest image among the plurality of images is obtained.

For this purpose, the focus adjustment may be made by the focus adjusting unit 370 of FIG. 3. The focus adjuster 370 of FIG. 3 includes a focus lens and a focus driver, and may drive the zoom lens to move the position of the zoom lens. The focus driver may include a focus motor M _F and a lens driver 210 to drive the focus lens to move the position of the focus lens.

The compensation lens compensates for the overall refractive index and is not driven separately. Reference numeral M _A denotes an aperture adjusting motor M _A for driving an aperture (not shown).

In the filter section of the optical system OPS, an optical low pass filter removes optical noise of high frequency components. Infra-Red cut filter cuts the infrared component of the incident light.

The photoelectric conversion unit OEC may include an imaging device such as a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS). The photoelectric conversion unit OEC converts light from the optical system OPS into an electrical analog signal.

The analog-to-digital converter may include a CDS-ADC (Correlation Double Sampler and Analog-to-Digital Converter) device 201. The analog-to-digital converter processes the analog signal from the photoelectric converter (OEC), removes the high frequency noise, adjusts the amplitude, and converts the analog signal into a digital signal. Here, the digital signal processor 207 controls the timing circuit 202 to control the operation of the photoelectric converter OEC and the analog-to-digital converter 201.

The optical system OPS, the photoelectric conversion unit OEC, the CDS-ADC element 201, and the like may be included in the image input unit 310 of FIG. 3.

The real time clock 203 provides time information to the digital signal processor 207. The digital signal processor 207 processes digital signals from the CDS-ADC element 201 to generate digital image signals classified into luminance (Y value) and chromaticity (R, G, B) signals.

The light emitting unit LAMP driven by the microcontroller 212 under the control of the main controller built in the digital signal processor 207 includes a self-timer lamp, an auto-focus lamp, a mode indicating lamp, a flash standby lamp, and the like. May be included.

The user input unit INP may include a direction button 21, a wide-angle zoom button W, a telephoto-zoom button T, and the like. The user input unit INP may be included in the user manipulation unit 360 of FIG. 3.

The digital image signal from the digital signal processor 207 is temporarily stored in the DRAM (Dynamic Random Access Memory) 204. The EEPROM (Electrically Erasable and Programmable Read Only Memory) 205 stores algorithms and setting data such as a boot program and a key input program required for the operation of the digital signal processor 207. In the memory card interface 206, a user's memory card may be attached or detached.

The EEPROM 205 may store a zoom table for zoom adjustment, a focus table for focus adjustment, and a zoom level interval for zoom bracketing shooting.

The digital signal processor 207 and / or the microcontroller 212 may be included in the controller 320 of FIG. 3 according to the present invention. The digital signal processor 207 and / or the microcontroller 212 may also be equipped with cache memory as temporary storage space.

In this case, the cache memory and the DRAM 204 may be included in the first storage unit 330 of FIG. 3 that temporarily stores the zoom level interval and the input image for zoom bracketing imaging. The cache memory included in the first storage unit 330 of FIG. 3 may be included separately from the digital signal processor 207 and / or the micro controller 212.

The memory card recognized through the memory card interface 206 may be included in the second storage unit 340 of FIG.

The digital image signal from the digital signal processor 207 is input to the display panel driver 214, whereby the image is displayed on the display panel 215.

The controller 200 of the digital image processing apparatus may further include display units 214 and 215. The display units 214 and 215 may include a display panel 215 and a display panel driver 214 for driving the display panel 215. The display units 214 and 215 may be included in the display unit 350 of FIG. 3 according to the present invention.

On the other hand, the digital image signal from the digital signal processor 207 can be transmitted by serial communication via a universal serial bus (USB) connection portion 31a or an RS232C interface 208 and the connection portion 31b thereof, and a video filter ( 209 and through the video output unit 31c. Here, the digital signal processor 207 may incorporate a microcontroller therein.

The audio processor 213 outputs the audio signal from the microphone MIC to the digital signal processor 207 or the speaker SP, and outputs the audio signal from the digital signal processor 207 to the speaker SP.

3 is a block diagram of a digital image processing apparatus 300 according to a preferred embodiment of the present invention. The digital image processing apparatus 300 may be controlled by the control method S400 of the digital image processing apparatus illustrated in FIG. 4.

Referring to the drawings, the digital image processing apparatus 300 includes an image input unit 310; The control unit 320; Storage units 330 and 340; Display unit 350; A user manipulation unit 360; A focus adjuster 370; And a zoom adjusting unit 380.

The image input unit 310 receives an input image. The zoom controller 380 adjusts the zoom level of the input image. The focus adjusting unit 370 adjusts the focus of the input image. The controller 320 sets a center region in the input image and controls zoom bracketing to be performed without adjusting focus on the center region.

The digital image processing apparatus 300 according to the present invention selects an appropriate zoom adjustment method according to the timing of zoom bracketing adjustment, so that no separate focus adjustment is required during zoom bracketing shooting. Therefore, it is possible to shorten the time required for focus adjustment at the time of zoom bracketing and to perform zoom bracketing shooting in a short time.

In addition, since the digital zoom-in is performed by fixing the position of the center point of the center area in the input image during zoom bracketing shooting by zoom-in, zoom bracketing shooting can be performed while maintaining the composition set by the first user.

The face included in the input image input through the image input unit 310 may be searched to detect a face area occupied by the face in the entire area of the input image.

The input image may be input by the currently set zoom level. The face area is detected from the input image by the currently set zoom level. In this case, face detection may be performed by a conventional face detection algorithm. Face detection may be performed using color and shape information of the face.

Adjust the focus on the input image by the currently set zoom level. In this case, the focus adjustment may be an automatic focus adjustment performed based on a specific region of the input image. The input image input by auto focusing according to the currently set zoom level may be photographed by default.

Shooting may be performed on the input image initially input by the currently set zoom level without additional zoom adjustment. At this time, the zoom level at which the currently set zoom level is most concerned with the user is likely. Accordingly, by photographing the input image first input by the currently set zoom level, it is possible to take a picture according to the zoom level set by the user even during zoom bracketing shooting.

The face region may be detected in the input image, and the face region may be set as the center region when the face region is detected in the input image. When the face area is not detected in the input image, the focus area for adjusting the focus may be set as the center area.

Meanwhile, as illustrated in FIGS. 9 and 10, when a plurality of face regions are detected, a specified face may be recognized and the recognized face region may be set as a center region.

When the current zoom level is a set wide end, zoom bracketing photography may be performed by digital zoom-in. In this case, the digital zoom-in may be performed by fixing the position of the center point of the center area in the input image.

Until the set zoom limit is reached, the user can generate and store a zoom-in image by digitally zooming in on the current zoom level.

In this case, if the optical zoom is used, an additional focus adjustment step may be required after the zoom level is changed, which may take additional time.

However, when zooming in using the digital zoom as in the present invention, it is possible to capture a zoom-in image of a desired angle of view by trimming without additional focus adjustment. As image sensor technology is developed to improve the resolution of digital cameras and super resolution technology is developed, the problem of resolution degradation can be minimized.

When the current zoom level is a set telephoto, zoom bracketing photography may be performed by optical zooming out. When the zoom out image is input by optically zooming out the current zoom level until the set zoom limit is reached, the face area is detected from the input image, and the face area is detected from the zoom out image, Can be taken.

Therefore, zoom bracketing shooting can be performed by optical zoom-out without a separate focus adjustment step during zoom-out bracketing shooting. Accordingly, it is possible to greatly improve the operation time which is a problem in conventional zoom bracketing photography.

Move the current zoom level to the wide end when the current zoom level is a medium level close to the wide end, and move the current zoom level to the telephoto end when the current zoom level is a medium level close to the telephoto end. have. At this time, the focus adjustment may be performed at the current zoom level moved to the wide-angle end or the telephoto end.

The zoom level may be adjusted by the zoom controller 380. The zoom adjusting unit 380 may include a zoom lens and a zoom driver. The zoom driver may include a zoom motor (M _z of FIG. 2) and a lens driver (210 of FIG. 2) to drive the zoom lens to move the position of the zoom lens. In this case, the zoom level may be adjusted in preset step units.

The focus adjustment may be performed by the focus adjustment unit 370. The focus adjuster 370 may include a focus lens and a focus driver to drive the zoom lens to move the position of the zoom lens. The focus driver may include a focus motor M _F and a lens driver 210 to drive the focus lens to move the position of the focus lens.

The display unit 350 may display the input image in live view. In this case, each input image input by adjusting the zoom level may be displayed in live view.

The image input unit 310 receives an input image from the outside. The image input unit 310 may include an optical system (OPS), a photoelectric converter (OEC), a CDS-ADC device 201, and the like illustrated in FIG. 2.

The controller 320 may include an image input unit 310; The control unit 320; Storage units 330 and 340; Display unit 350; A user manipulation unit 360; A focus adjuster 370; And the zoom adjusting unit 380 to perform auto zoom bracketing shooting. The controller 320 may include the digital signal processor 207 and / or the microcontroller 212 illustrated in FIG. 2.

The input unit and the captured image may be stored in the storage units 330 and 340. The storage units 330 and 340 may include a first storage unit 330 and a second storage unit 340. The input image may be temporarily stored in the first storage unit 330. The captured image may be stored in the second storage unit 340.

The display unit 350 may include the display panel 25 shown in FIG. 1 and / or the display panel driver 214 and the display panel 215 of FIG. 2. The user may input a desired command from the outside through the user manipulation unit 360. The user manipulation unit 360 may include a shutter release button 26 and a power switch 28 of FIG. 1 and / or a user input unit INP of FIG. 2.

According to the present invention, by selecting an appropriate zoom adjustment method according to the timing of the zoom bracketing adjustment, it is possible to shorten the time required for the auto focus adjustment.

4 is a flowchart illustrating a control method (S400) of a digital image processing apparatus as a preferred embodiment according to the present invention. FIG. 5 is a flowchart illustrating a process (S500) of performing zoom bracketing photographing on a central area in the control method (S400) of the digital image processing apparatus of FIG. 4.

The control method S400 of the digital image processing apparatus may be implemented in the digital image processing apparatus of FIGS. 2 and / or 3 and the control apparatuses 200 and 300 thereof. To this end, the control method S400 of the digital image processing apparatus according to the present invention may be a program or algorithm stored in the storage means of FIG. 2 or implemented in the form of a semiconductor chip such as firmware.

Therefore, in the method S400 of controlling the digital image processing apparatus, the same matters as those described for the digital image processing apparatus and the control apparatuses 200 and 300 will be referred to, and detailed description thereof will be omitted.

Referring to the drawings, the control method of the digital image processing apparatus (S400), the input image input step (S420); Face detection step S430; Focus adjusting step S440; Photographing step S450; Center region setting step (S460 to S480); And a zoom bracketing step (S500).

In the input image input step (S420), the input image is received. In the face detection step S430, a face region is detected from an input image. In the focus adjusting step S440, the focus is adjusted with respect to the input image. In the photographing step S450, an input image is photographed.

In the center area setting steps S460 to S480, a center area is set in the input image. In the zoom bracketing step S500, zoom bracketing shooting is performed without adjusting focus on the center area.

The control method (S400) of the digital image processing apparatus according to the present invention selects an appropriate zoom adjustment method according to the timing of zoom bracketing adjustment, so that no separate focus adjustment is required during zoom bracketing shooting. Therefore, it is possible to shorten the time required for focus adjustment at the time of zoom bracketing and to perform zoom bracketing shooting in a short time.

In addition, since the digital zoom-in is performed by fixing the position of the center point of the center area in the input image during zoom bracketing shooting by zoom-in, zoom bracketing shooting can be performed while maintaining the composition set by the first user.

The control method (S400) of the digital image processing apparatus may include a smart auto zoom bracketing function determination step (S410). In the smart auto zoom bracketing function determination step (S410), it is determined whether the current mode is the smart auto zoom bracketing function on, and when the smart auto zoom bracketing function is on, According to the smart auto zoom bracketing function can be performed.

Smart Auto Zoom Bracketing function selects an appropriate zoom adjustment method according to whether the angle of zoom bracketing adjustment is set to the wide-angle end or telephoto end, thereby eliminating the need for additional focus adjustment during zoom bracketing shooting. to be.

In the input image input step (S420), the input image is input by the currently set zoom level. In the face detection step S430, the face area is detected from the input image at the currently set zoom level. In this case, face detection may be performed by a conventional face detection algorithm. Face detection may be performed using color and shape information of the face.

In the focus adjusting step S440, the focus is adjusted with respect to the input image at the currently set zoom level. In this case, the focus adjustment may be an automatic focus adjustment performed based on a specific region of the input image.

When a face region is included in the input image, auto focus adjustment may be performed based on the face region. When the face area is not included in the input image, auto focus adjustment may be performed on a predetermined area of the center portion of the input image or a plurality of focus areas of a preset position with respect to the input image.

In the photographing step S450, an input image input by auto focusing according to the currently set zoom level may be photographed. In the photographing step S450, the first input image input by the currently set zoom level may be photographed without additional zoom adjustment.

At this time, the zoom level at which the currently set zoom level is most interested in the user is likely. Accordingly, by photographing the input image first input by the currently set zoom level, it is possible to take a picture according to the zoom level set by the user even during zoom bracketing shooting.

In the center area setting steps S460 to S480, a center area that is the center of digital zoom-in in the input image is set. The center area setting steps S460 to S480 may include a face detection determining step S460 and a center area setting step S470 or S480.

In the face detection determination step (S460), it is determined whether a face region is detected in the input image. In the center area setting steps S470 and S480, a center area is set according to whether a face area is detected. The central area setting steps S470 and S480 may include a first setting step S470 and a second setting step S480 in which any one is performed according to the determination result in the face detection determining step S460.

In this case, when the face region is detected in the input image as a result of the determination in the face detection determination step S460, the first setting step S470 may be performed. In addition, when the face region is not detected in the input image, the second setting step S480 may be performed.

In the first setting step S470, the face area may be set as the center area. In the second setting step S480, the focus area for focus adjustment may be set as the center area.

Meanwhile, as illustrated in FIGS. 9 and 10, a plurality of face regions may be detected. In this case, when a plurality of face areas are detected, a predetermined face may be recognized and the recognized face area may be set as the center area.

9 illustrates an input image 90 in which a plurality of face regions 91, 92, and 93 are detected during zoom bracketing according to the present invention. FIG. 10 illustrates a zoom in image 90a generated by performing digital zoom in on the input image 90 in the embodiment shown in FIG. 9.

9 and 10, three eye face regions 91, 92, and 93 are detected in the input image 90, and a face of a left eye is designated as a predetermined face so that the specified face is recognized. Can be a recognition face. Accordingly, the face area 91 of the recognition face may be set as the center area. In this case, face recognition may be performed by comparing with a face database stored in advance by a conventional face recognition algorithm.

Therefore, when zoom bracketing is taken in the zoom bracketing operation (S500), the zoom-in image 90a may be captured by being zoomed in using the face area 91 of the left eye as the center region. In the zoom-in image 90a, the face area 91a of the left eye may be the center area, and the zoom-in may be performed with respect to the center point of the center area.

In another embodiment, when a plurality of faces are detected, zoom-in may be performed based on the face region 92 of the face closest to the center point of the input image.

When it is determined that the face area is not detected in the input image, the focus area may be set as the center area in the second setting step S480. In this case, the focus area may be the focus area of the first input image captured by the currently set zoom level. In this case, since there is no zoom limit due to the limitation of the face area, shooting at all zoom stages is possible.

When the automatic focus adjustment is performed by the plurality of focus areas, the zoom in may be performed based on the center point of the focus area located at the position closest to the input image.

In the zoom bracketing step S500, zoom bracketing shooting is performed without adjusting focus on the center area. In the zoom bracketing step S500, a picture may be automatically taken for each zoom level while adjusting the zoom level at a predetermined interval within the zoom limit range of the set zoom level.

The zoom bracketing step S500 may include a zoom level determining step S510, a zoom in bracketing shooting step S520, a zoom out bracketing shooting step S530, and a zoom bracketing preparation step S540. have.

In the zoom level determining step S510, the current zoom level is determined. In the zoom-in bracketing shooting step (S520), when the current zoom level is set to the wide-angle end, zoom bracketing shooting is performed by digital zoom-in. In the zoom-out bracketing photographing step (S530), when the current zoom level is a telephoto set, zoom bracketing photographing is performed by optical zoom-out.

In the zoom bracketing step S500, when the zoom level is moved from the wide end to the telephoto end, the zoom bracketing photographing may be performed by digital zoom in by the zoom in bracketing photographing step S520. have. In this case, if the optical zoom is used, an additional focus adjustment step may be required after the zoom level is changed, which may take additional time.

However, when zooming in using the digital zoom as in the present invention, it is possible to capture a zoom-in image of a desired angle of view by trimming without additional focus adjustment. As image sensor technology is developed to improve the resolution of digital cameras and super resolution technology is developed, the problem of resolution degradation can be minimized.

In addition, when the zoom level is moved from the telephoto end to the wide end, zoom bracketing may be performed by optical zoom-out by the zoom-out bracketing photographing step (S530). As shown in FIG. 6, the focus focused at the wide-angle end increases as the distance goes to the telephoto end, but when the focus is focused on the telephoto end and moves to the wide-angle end, the focus goes out of focus.

The graph shown in FIG. 6 shows that when focusing at a wide-angle end and zooming in to a telephoto end, the focus is out of focus due to optical characteristics. However, when focusing from the telephoto end and moving to the wide-angle end, the degree of out of focus is reduced, so there is no need to focus additionally after the zoom operation.

Therefore, in the zoom-out bracketing photographing step S530, zoom bracketing photographing may be performed by optical zoom-out without a separate focus adjustment step. Accordingly, it is possible to greatly improve the operation time which is a problem in conventional zoom bracketing photography.

In the zoom bracketing preparation step (S540), when the current zoom level is an intermediate level instead of the wide end and the telephoto end, the zoom level is moved to the wide end or the telephoto end to prepare for the zoom bracketing shooting.

The zoom bracketing preparation step S540 may include a zoom end determining step S541, a wide-angle end moving step S542, a telephoto end moving step S543, and a focus adjusting step S544 and S545.

In the zoom stage determining step S541, it is determined whether the current zoom level is close to the wide-angle end or the telephoto end. In the wide-angle end moving step S542, when the current zoom level is an intermediate level close to the wide-angle end, the current zoom level is moved to the wide-angle end.

In the telephoto end moving step (S543), the current zoom level is moved to the telephoto end when the current zoom level is an intermediate level close to the telephoto end. In the focus adjustment steps S544 and S545, focus adjustment is performed at the current zoom level. In this case, the focus adjustment may be performed by normal automatic focus adjustment.

In the zoom-in bracketing shooting step S520, digital zoom-in may be performed with respect to the current zoom level until the set zoom limit is reached, and zoom bracketing shooting may be performed by digital zoom-in. In this case, the zoom limit may be a telephoto that corresponds to a hardware zoom limit. In addition, the zoom limit may be a telephoto corresponding to a preset software zoom limit within the hardware zoom limit.

In another embodiment, the zoom limit may be a zoom limit that is maximally moved in the telephoto direction so that the center region can be photographed without being cut off.

In the zoom-in bracketing photographing step (S520), a plurality of pictures may be taken according to different zoom levels while moving the zoom level from a set wide angle end to a set telephoto end. At this time, it is preferable to digitally zoom in by fixing the position of the center point of the center area in the first captured image.

7 and 8 illustrate a zoom-in image 80 generated by performing digital zoom-in on the input image 70 and the input image 70 before zooming, respectively, in zoom bracketing photographing.

In the embodiment shown in the drawing, in the input image 70, the face area becomes the center area 71, and the digital zoom-in is fixed by fixing the position of the center point 71a of the center area 71 within the zoom limit 72 range. can do. At this time, the zoom limit 72 may be a range in which the center region is not cut.

In addition, the position of the center point 81a of the center area 81 in the zoom-in image 80 may be the same point as the center point 71a of the input image 70. In addition, the zoom limit 82 in the zoom-in image 80 may be the same area as the zoom limit 72 in the input image.

The zoom-in bracketing photographing step S520 may include a digital zoom-in step S521, a zoom limit determining step S522, and a storing step S523.

In the digital zoom-in step S521, a zoom-in image is generated by digitally zooming in on the current zoom level. In the zoom limit determination step (S522), it is determined whether the current zoom level exceeds the zoom limit. In the storing step S523, the zoom-in image is stored when the current zoom level does not exceed the zoom limit.

As a result of the determination in the zoom limit determining step S522, when the current zoom level does not exceed the zoom limit, the zoom limit determining step S522 and the storing step S523 are repeatedly performed, so that the center area is not cut. You can save the zoom-in image by digital zoom-in.

Therefore, when digital zoom-in bracketing is taken, the face coordinates corresponding to the center area fall within a predetermined range of the screen so that the face is not cut off.

The zoom-in bracketing photographing step S520 includes a zoom limit determining step S522, and performs the zoom limit determining step S522 and the storing step S523 while changing the zoom level until the zoom limit is reached. A plurality of zoom-in images may be photographed for different zoom levels.

In addition, when zooming in by zoom-in, the face area corresponding to the center area of interest may not be cut and the zoom-in image may be captured.

In addition, in the zoom-out bracketing photographing step (S530), a plurality of pictures may be taken according to different zoom levels while moving the zoom level from the set telephoto end to the set wide-angle end. At this time, the optical zoom out may be performed with respect to the current zoom level until the set zoom limit is reached, and zoom bracketing photography may be performed by the optical zoom out.

In the zoom-out bracketing shooting step S530, since the optical zoom operates and the angle of view becomes wider, the face is not cut off when the zoom bracketing is taken. However, when taking a portrait picture, it is necessary to make sure that the face area does not come out too small.

In this case, when the distance is far, information necessary for the face detector may be so small that it cannot be detected. Therefore, photographing may be performed while checking whether a face is detected by the face detector during zoom-out bracketing photographing.

The zoom out bracketing photographing step S530 may include a zoom out step S531, a zoom out image input step S532, and a zoom out image photographing step S533 to S537.

In the zoom out step S531, the optical zoom is performed with respect to the current zoom level. In the zoom out image input step (S532), the zoom out image is input by the zoom level due to the zoom out. In the zoom out image photographing step (S534 to S537), the zoom out image is captured.

The zoom-out image capturing steps S534 to S537 may include a face area detecting step S534, a face area determining step S535, and a shooting step S536 and S537.

In the face region detection step S534, the face region is detected in the zoom-out image. In the face region determination step S535, it is determined whether a face region is detected in the zoom-out image. In the photographing steps S536 and S537, the zoom-out image is photographed.

To this end, it is first determined whether a face region is detected in the input image (S533), and when a face region is detected in the input image, the face is detected in the face region detection step (S534) and the face region determination step (S535). Areas can be detected and detected.

In this case, when the face area is not detected in the zoom-out image, the zoom-out bracketing photographing step S530 is terminated. When the face area is detected in the zoom-out image, the zoom-out image is photographed in the photographing step S536.

Accordingly, the image may be zoomed out to the extent that the face region can be recognized in the image including the face region.

When the face region is not detected in the input image, the face region detection step S534 and the face region determination step S535 are not performed, but the imaging of the zoom-out image is performed in the photographing step S537.

In addition, the zoom-out image may be captured when the face area corresponding to the center area of interest is identifiable when the zoom bracketing is taken by the zoom-out.

According to the present invention, the time required for auto focus adjustment can be shortened by selecting an appropriate zoom adjustment method according to the timing of zoom bracketing adjustment.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

1 is a diagram illustrating a rear surface of a digital camera as an embodiment of a digital image processing apparatus according to the present invention.

FIG. 2 is a block diagram schematically illustrating a control apparatus that may be included in the digital camera of FIG. 1.

3 is a block diagram schematically showing a digital image processing apparatus according to a preferred embodiment of the present invention.

4 is a flowchart schematically illustrating a control method of a digital image processing apparatus as a preferred embodiment according to the present invention.

FIG. 5 is a flowchart schematically illustrating a process in which zoom bracketing photographing is performed with respect to a center area in the control method of the digital image processing apparatus of FIG. 4.

6 is a diagram schematically illustrating a degree of deviation from a focus when tracking a focus position during a zoom operation in zoom bracketing photographing according to the present invention.

7 is a diagram schematically illustrating an input image before zooming in zoom bracketing photographing according to the present invention.

FIG. 8 is a diagram schematically illustrating a zoom-in image generated by performing digital zoom-in on the input image of FIG. 7.

9 is a diagram schematically illustrating an input image in which a plurality of face areas are detected during zoom bracketing photographing according to the present invention.

FIG. 10 is a diagram schematically illustrating a zoom-in image generated by performing digital zoom-in on the input image of FIG. 9.

Claims (20)

Receiving an input image; Detecting a face region in the input image; Adjusting a focus on the input image; Photographing the input image; Setting a center area in the input image; And And performing zoom bracketing photographing on the center area without adjusting focus. The method of claim 1, Setting an area to the center, Determining whether a face region is detected in the input image; Setting the face area as the center area when the face area is detected in the input image; and And setting a focus area for adjusting the focus as the center area when the face area is not detected in the input image. The method of claim 2, And recognizing a specified face when a plurality of face areas are detected, and setting the recognized face area as the center area. The method of claim 1, Performing the zoom bracketing shooting, Determining the current zoom level, Performing zoom bracketing shooting by digital zoom-in when the current zoom level is a set wide-angle end, and And performing zoom bracketing imaging by optical zooming out when the current zoom level is a set telephoto end. The method of claim 4, wherein Performing the zoom bracketing shooting, Moving the current zoom level to the wide-angle end when the current zoom level is an intermediate level close to the wide-angle end, Moving the current zoom level to the telephoto end when the current zoom level is an intermediate level close to the telephoto end, and And performing focus adjustment at the current zoom level. The method of claim 4, wherein A control method of a digital image processing apparatus which performs zoom bracketing shooting by digital zoom-in by digitally zooming in on a current zoom level until reaching a set zoom limit. The method of claim 6, And controlling the digital zoom-in by fixing a position of a center point of the center area in the input image. The method of claim 7, wherein Performing zoom bracketing shooting by the digital zoom in, Generating a zoom-in image by digitally zooming in on a current zoom level; Determining whether a current zoom level has exceeded the zoom limit, and And storing the zoom-in image when a current zoom level does not exceed the zoom limit. The method of claim 1, A control method of a digital image processing apparatus for performing optical bracketing shooting by optical zooming out by optically zooming out a current zoom level until reaching a set zoom limit. 10. The method of claim 9, Performing zoom bracketing shooting by the optical zoom out, Optically zooming out the current zoom level, Receiving a zoom-out image based on the zoom level by the zoom-out; and And controlling the zoom-out image. The method of claim 10, Performing zoom bracketing shooting by the optical zoom out, Detecting a face region in the zoom-out image when the face region is detected in the input image; and And photographing the zoom-out image when the face area is detected in the zoom-out image. An image input unit which receives an input image; A zoom adjuster for adjusting a zoom level of the input image; A focus adjuster for adjusting a focus of the input image; And And a controller configured to set a center region in the input image and to perform zoom bracketing photographing without adjusting focus on the center region. The method of claim 12, And a digital image processing apparatus for performing photographing by adjusting focus on the input image. The method of claim 13, Detecting a face region from the input image; Set the face area as the center area when the face area is detected in the input image; And a focus area for adjusting the focus as the center area when the face area is not detected in the input image. The method of claim 14, And recognizing a specified face when a plurality of face areas are detected, and setting the recognized face area as the center area. The method of claim 12, When the current zoom level is set to the wide end, zoom bracketing shooting is performed by digital zoom-in. And digital zoom out when the current zoom level is a set telephoto end. The method of claim 16, Move the current zoom level to the wide-angle end when the current zoom level is an intermediate level close to the wide-angle end, Move the current zoom level to the telephoto end when the current zoom level is an intermediate level close to the telephoto end, And a focus adjustment at the current zoom level. The method of claim 16, And digitally zoom in by fixing a position of a center point of the center area in the input image. The method of claim 16, A digital image processing apparatus which generates and stores a zoom-in image by digitally zooming in on a current zoom level until a set zoom limit is reached. The method of claim 16, When the zoom out image is input by optically zooming out the current zoom level until the set zoom limit is reached, the face region is detected from the input image, and the face region is detected from the zoom out image. Digital image processing apparatus for performing a zoom out image.

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