KR20090059512A - Image processing apparatus for compensating of lens part shading and method for controlling thereof - Google Patents

Abstract

An image processing apparatus for compensating the shading phenomenon of a lens unit and a control method thereof are provided to compensate the shading phenomenon easily in a replaceable lens unit. An image processing apparatus for compensating the shading phenomenon comprises a lens unit(10) and a body unit(300). The brightness information corresponding to each region of an image which is formed in image pick-up is stored. An information transfer unit receives the brightness information by being connected to the lens unit. A compensating unit performs the brightness correction uniformly for each region of the image.

Description

Image processing apparatus for compensating of lens part shading and method for controlling Technical Field

The present invention relates to an image processing apparatus for correcting a lens shading phenomenon and a control method thereof, and more particularly, to an image processing apparatus capable of easily correcting a lens shading phenomenon in an image processing apparatus equipped with an interchangeable lens unit and a control thereof. It is about a method.

 The image processing apparatus includes any apparatus that processes an image such as a digital camera, a personal digital assistant (PDA), a phone camera, a PC camera, or uses an image recognition sensor.

In such an image processing apparatus, an image input through an image pickup device may be displayed on a video display device. In addition, when the user presses the shutter release button, the user may capture and store the desired image as an image file. In general, an image processing apparatus stores an image file obtained by a photographing operation in a photographing mode on a storage medium, and displays an image on a display unit by reproducing the image file stored in the storage medium in a playback mode. Of course, the image file obtained by the shooting operation is also played back in the shooting mode.

Shading may occur in which the periphery of the image captured by the image processing apparatus is darker than the center portion. This is a distortion of the screen caused by the lens provided in the image processing apparatus. In order to solve this problem, an image processing apparatus including a function of brightening a peripheral portion of an image has been developed.

Recently, however, various lens units have been replaced and used in image processing apparatuses. In this case, each lens unit has different optical characteristics. Since the optical characteristics are different, the shape of the shading phenomenon is different in the image photographed using each lens unit, and the degree of darkening is also different. Therefore, the conventional image processing apparatus has a limitation in correcting the shading phenomenon caused by the respective lens parts that can be replaced and mounted.

The present invention provides a video processing apparatus and a control method for correcting the lens shading phenomenon that can improve the image quality characteristics, including a lens unit having brightness information, and a main body unit receiving and using the information to correct the shading. Can be.

According to an aspect of the present invention, there is provided an image processing apparatus for correcting a lens shading phenomenon, comprising: a lens unit having a memory storing brightness information corresponding to each region of an image formed by the lens unit; A lens unit shading phenomenon including a body unit including an information transfer unit capable of receiving brightness information stored in the display unit, and a correction unit configured to receive brightness information from the information transfer unit and uniformly correct brightness for each region of the image. An image processing apparatus for correcting the above is disclosed.

In the present invention, the lens unit may be interchangeable with types having different brightness information.

In the present invention, the memory may be a ROM or a flash memory.

According to another aspect of the present invention, a method of controlling an image processing apparatus for correcting a lens shading phenomenon, comprising: coupling the lens unit to a main body unit, recognizing the lens unit at the main body unit, and imaging by using the lens unit Acquiring the brightness information from the lens unit in which the brightness information of each region of the image formed is stored and uniformly correcting the brightness of each region of the image by using the brightness information obtained from the body unit. A control method of an image processing apparatus for correcting lens shading phenomena including performing the method is disclosed.

An image processing apparatus for correcting a lens shading phenomenon and a control method thereof according to the present invention facilitate a shading phenomenon in an interchangeable lens unit including a lens unit having brightness information and a body unit performing a correction function using the information. Can be corrected.

Although described with reference to the embodiment shown in the drawings it is merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Hereinafter, with reference to the embodiments of the present invention shown in the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 is a block diagram illustrating an image processing apparatus for correcting a lens shading phenomenon according to an exemplary embodiment of the present invention, and FIG. 2 is a block diagram illustrating a part of the image processing apparatus of FIG. 1.

The overall operation of the image processing apparatus is integrated by the CPU 100. In addition, the image processing apparatus includes an operation unit 200 including a key for generating an electrical signal from a user. The electrical signal from the operation unit 200 is transmitted to the CPU 100 so that the CPU 100 can control the image processing apparatus according to the electrical signal.

In the photographing mode, as the electrical signal from the user is applied to the CPU 100, the CPU 100 detects the signal and controls the lens driver 11, the aperture driver 21, and the imaging device controller 31. Accordingly, the position of the lens unit 10, the opening degree of the diaphragm 20, the sensitivity of the imaging device 30, and the like for autofocusing are controlled. In addition, the lens unit 10 may recognize the mounted lens unit 10, acquire brightness information stored in the lens unit 10, and correct the brightness of the screen using the information. When a data signal for an image is output from the image pickup device 30, it is converted into digital image data by the analog / digital converter 40, and input to the CPU 100 and the digital signal processor 50. The digital signal processor 50 performs digital signal processing such as gamma correction and white balance adjustment.

The image data output from the digital signal processor 50 is transmitted to the display controller 91 through the memory 60 or directly. The memory 60 is a concept including a ROM or a RAM. The display controller 91 controls the display 90 to display an image on the display 90. The image data output from the digital signal processing unit 50 may be input to the recording / reading control unit 70 through the memory 60, and the recording / reading control unit 70 may automatically or according to a signal from a user. The image data is recorded on the recording medium 80. Of course, the recording / reading control unit 70 reads image data from the image file stored in the recording medium 80 and inputs it to the display control unit 91 through the memory 60 so that the image is displayed on the display unit 90. You may.

FIG. 2 is a block diagram illustrating a part of an image processing apparatus for correcting a lens shading phenomenon of FIG. 1. Referring to FIG. 2, the image processing apparatus according to the present exemplary embodiment includes a main body 300 and a lens unit 10.

The lens unit 10 includes a memory 10a. The lens unit 10 is not used in a form fixed to the main body 300. That is, the lens unit 10 may be replaced by using the lens unit 10 having various characteristics.

The memory 10a includes brightness information of the lens unit 10. In more detail, brightness information corresponding to each area of an image generated when the image is captured using the lens unit 10 is provided. This is different depending on the structural characteristics of the lens unit 10 so that it is already stored in the memory 10a of the lens unit 10 at the time of manufacturing the lens unit 10.

FIG. 3 is a diagram illustrating brightness information corresponding to each area of an image formed when the image is formed by using the lens unit 10 of FIG. 1. This information is stored in the memory 10a of the lens unit 10. In more detail, the virtual image 400 is formed during imaging using the lens unit 10. The virtual image 400 includes a normal region 410 and a shading region 420. The brightness information may be expressed as a numerical value of the brightness of each area of the virtual image 400. That is, the brightness value may be a map or a lookup table, but is not limited thereto.

The shading phenomenon, which is one of the image quality distortions due to the lens unit 10, is a phenomenon in which the periphery of the captured original image is darker than the center portion. The virtual image 400 is a means for storing a shading phenomenon that varies depending on the characteristics of the lens unit 10 in the lens unit 10. The normal area 410 is an area where no shading phenomenon occurs, and the shading area 420 is an area where the shading phenomenon occurs and becomes darker than the normal area 410 which is a central part. Shading area 420 may be the same brightness, but may become darker toward the outside.

Since the memory 10a stores unique brightness information of the lens unit 10, different types of lens units 10 include a memory 10a in which different information is stored. That is, referring to FIG. 3, the shape and brightness of the normal region 410 and the shading region 420 of the virtual image 400 are different according to the type of the lens unit 10. The memory 10a may be a ROM or flash memory. However, the present invention is not limited thereto and may be a medium capable of storing information.

Referring to FIG. 2, the main body 300 includes an information transfer unit 301 and a correction unit 302. The information transfer unit 301 receives information from the memory 10a of the lens unit 10. That is, brightness information of each region of the image as shown in FIG. 3 is received.

The correction unit 302 receives the brightness information from the information transfer unit 301 and performs a function of correcting the brightness so that the brightness of the entire area of the image is uniform. The correction unit 302 illustrated in FIG. 2 may be part of the CPU 100 illustrated in FIG. 1. Of course, although not shown in Figure 1, the correction unit 302 may be a separate independent component that is not part of the CPU.

The correction unit 302 adjusts the brightness of the dark areas of the image by using the data stored in the memory 10a of the lens unit 10 to correct the shading phenomenon of the lens unit 10. Make the brightness uniform over the whole area. That is, the brightness is adjusted by weighting the brightness of each area of the image by using the information received from the memory 10a displaying the characteristics of the lens unit 10. Detailed description thereof will be described later.

4 is a plan view schematically illustrating the image processing apparatus of FIG. 1, and FIG. 5 is a rear view of the image processing apparatus of FIG. 1.

Referring to FIG. 4, a strobe 12, a shutter release button 13, a power switch 3, a lens unit 10, and a connection unit 310 are provided at the front of the image processing apparatus according to the present invention. Is placed. Although not shown, a microphone, a self-timer lamp, a flash light sensor, and a remote receiver may be disposed.

The strobe 12 emits light when the amount of light is insufficient, such as when imaging in a dark place, to prevent deterioration of image quality. The strobe 12 may be built-in or may be used to pop up only when driven.

The self-timer lamp (not shown) operates in the self-timer mode for a set time from the time when the shutter release button 13 is pressed to the time when the image starts to be captured. The flash-light amount sensor (not shown) detects the light amount when the strobe 12 operates and inputs the light amount to the CPU 100 of the image processing apparatus through a microcontroller (not shown).

The connection part 310 is disposed at one end of the main body part 300 to be coupled to the lens part 10. The information transfer unit 302 illustrated in FIG. 2 may be disposed in the connection unit 310 to receive information of the lens unit 10.

The remote receiver (not shown) receives a command signal from a remote controller (not shown), for example, a photographing command signal, and inputs it to the CPU 100 through the microcontroller.

Referring to FIG. 5, the rear of the image processing apparatus according to the present invention has a mode dial 14, function buttons 15, manual focusing / delete / reduction button 36, manual adjustment / playback / stop / enlargement. Button 37, playback mode button 42, speaker SP, monitor button 32, auto-focus lamp 33, viewfinder 17, flash standby lamp 34, display panel 35, Wide angle-zoom button 39W, telephoto-zoom button 39T, external interface 16, and the like.

The mode dial 14 is any one of operation modes of the photographing apparatus, for example, a simple shooting mode, a program shooting mode, a portrait shooting mode, a night view shooting mode, a manual shooting mode, a movie shooting mode, a user setting mode, and a recording mode. Is used for the user to select.

The function buttons 15 may be used by the user to select specific functions of the digital photographing apparatus, may be used to move an image when playing back an image on the display panel, and may be activated on a menu screen on the display panel 35. Used as direction-move buttons, and so on.

Manual-adjust / play / stop / enlarge button 37 is used for manual adjustment of certain conditions. Further, in the playback mode, when the user presses the manual-adjustment / playback / stop / enlarge button 37 while the user selects any video file, the user may play or stop the selected video file. The image displayed on the display unit may be enlarged.

The manual-focusing / deleting / reducing button 36 may be used for the user to manually focus or delete operation in the shooting mode. The image displayed on the display unit may be reduced. The monitor button 32 can be used by the user to control the operation of the display panel 35. The playback mode button 42 can be used for switching to playback or shooting mode.

The auto-focus lamp 33 operates when the focus is well achieved. The flash standby lamp 34 operates when the strobe 12 is in an operation standby state.

Of course, the image processing apparatus illustrated in FIGS. 4 and 5 is just one embodiment of the image processing apparatus according to the present invention, and may be various image processing apparatuses in which lenses can be interchanged.

Operations, effects, and the like of the image processing apparatus according to the above-described embodiment will be described in detail.

FIG. 6 is a diagram schematically illustrating a method of correcting a shading phenomenon by using an image processing apparatus that corrects a lens shading phenomenon according to an exemplary embodiment of the present disclosure.

Referring to FIG. 6, the brightness of the image is corrected by giving a relatively higher brightness weight to the peripheral area 520 than the center area 510 of the image 500 to be displayed on the display panel 35. The center region 510 of FIG. 6 corresponds to the normal region 410 of the virtual image 400 of FIG. 3. The peripheral area 520 of FIG. 6 corresponds to the shading area 420 of FIG. 3.

When the lens unit 10 is mounted on the main body 300, the information transmitting unit 301 of the main body 300 may be configured as the normal region 410 of the virtual image 400 from the memory 10a of the lens unit 10. Information about the shading area 420 is received. The information transfer unit 301 transfers this information to the correction unit 302 of the main body unit 300.

Accordingly, the correction unit 302 corresponds to the normal region 410, that is, the central region 510, which is a portion where brightness is normally applied, and applies the brightness weight relatively low, and corresponds to the shade region 420. The surrounding area 520, which is a dark part where the shading phenomenon occurs, performs brightness adjustment by applying a relatively high brightness weight. The greater the brightness weight, the greater the correction effect. As a result, the brightness of the central area 510 and the peripheral area 520 of the image 500 may be uniformly adjusted.

7 and 8 are specific examples of a method of correcting such a shading phenomenon. 7 is a table obtained by dividing the entire area of the image 600 in a matrix form. In the image 600, region A and region B are one region belonging to the peripheral region 520 of FIG. 6, and region C is one region belonging to the central region 510.

Region A and region B are darker than region C. Therefore, image processing to brighten the A area and the B area is necessary. The image is processed by applying the brightness weights of the A and B regions higher than the C region. In some cases, the brightness weight of the A region may be higher than that of the B region according to the characteristics of the lens unit. That is, it is applied to the case where the A region is darker than the B region because the shading phenomenon is severe toward the outer side of the image due to the characteristics of the lens unit.

When the brightness weight is applied, each weight may be applied to each region, but representative values may be assigned to the x-axis and the y-axis to multiply these values. For example, if x1 = 2 and y1 = 1, the area A applies 2, which is the product of these. Also, if x2 = 1 and y2 = 1.5, the area B applies 1.5 multiplied by them. Similarly, if x3 = 1 and y3 = 1, the area C applies 1, which is the product of these. Each of the x and y values does not correspond to a distance on the coordinate plane. It can be applied by assigning constant values to each x and y.

FIG. 8 illustrates a region in which the image 600 is divided into a plurality of concentric circles. The first region 710, the second region 720, the third region 730, and the fourth region 740 are provided. The first area 710 corresponds to the center area 510 of FIG. 6. The second area 720, the third area 730, and the fourth area 740 correspond to the peripheral area 520 of FIG. 6. Of course, there may be more concentric circles.

The second area 720, the third area 730, and the fourth area 740 are darker areas than the first area 710. Therefore, image processing to brighten the second area 720, the third area 730, and the fourth area 740 is necessary. An image is processed by applying the brightness weights of the second area 720, the third area 730, and the fourth area 740 higher than the weights of the first area 710.

In some cases, the brightness weight of the third region 730 is higher than that of the second region 720 and the brightness weight of the fourth region 740 is higher than the third region 730 according to the characteristics of the lens unit. can do. That is, due to the characteristic of the lens unit, the shading phenomenon increases toward the outside of the image, so that the third region 730 is darker than the second region 720 and the fourth region 740 is darker than the third region 730.

For example, a weight of 1 may be applied to the first region 710, 2 to the second region 720, 3 to the third region 730, and 4 to the fourth region 740. The higher the weight, the wider the brightness correction. As a result, the shading phenomenon caused by the lens part is corrected to prevent the peripheral part from darkening, thereby improving the image quality characteristics.

9 is a flowchart schematically illustrating a control method of an image processing apparatus for correcting a lens shading phenomenon according to an exemplary embodiment of the present invention.

According to an exemplary embodiment of the present invention, a method of controlling an image processing apparatus for correcting a lens shading phenomenon may be performed by coupling a lens unit to a main body (802), recognizing the lens unit at a main body (803), and using a lens unit. Obtaining the brightness information from the lens unit in which the brightness information of each region of the image to be formed at the time of imaging is stored in the main body unit 804 and performing the brightness correction in the main body unit 805.

In operation 802, the lens unit is coupled to the body unit. At this time, the lens unit is not limited to one that can be combined with the main body. It can be mounted while exchanging lens parts having various optical characteristics.

Initializing the main body unit 801 may be performed before the lens unit is coupled to the main body unit. Since the types of the lens parts may be various, the used lens part may be separated from the main body part, and the main body part may be initialized every time the new lens part is combined to facilitate subsequent lens part recognition and information acquisition.

In the step 803 of recognizing the lens unit in the main body unit recognizes the lens unit mounted on the main body to determine the characteristics and types of the lens unit. At this time, each lens unit stores the brightness information for each area of the image generated by the shading phenomenon. Such information may be stored in memory. The main body portion is connected to the memory of the lens portion to prepare for information acquisition.

In operation 804, obtaining brightness information from the lens unit, the main body unit acquires brightness information of each region of the image resulting from the shading phenomenon of the lens unit. As shown in FIG. 6, the brightness information is a set of values obtained by quantifying the degree of brightness of the central area and the peripheral area, and includes brightness information corresponding to each position on the image.

 In operation 805, brightness correction is performed in the main body using the brightness information stored in the lens unit. The difference in brightness caused by the shading phenomenon of the lens part is corrected. The shading phenomenon increases the weight for the brightness correction in the peripheral area of the dark image, and the center area does not become dark due to the shading phenomenon. As a result, the surrounding area of the captured image is not dark but has a uniform brightness as a whole, thereby improving image quality characteristics.

1 is a block diagram illustrating an image processing apparatus for correcting a lens shading phenomenon according to an exemplary embodiment of the present invention.

FIG. 2 is a block diagram illustrating a part of the image processing apparatus of FIG. 1.

FIG. 3 is a diagram illustrating brightness information corresponding to each region of an image formed during imaging by using the lens unit of FIG. 1. FIG.

4 is a plan view schematically illustrating the image processing apparatus of FIG. 1.

5 is a rear view of the image processing apparatus of FIG. 1.

6 to 8 are diagrams illustrating a method of correcting a lens unit shading phenomenon using an image processing apparatus according to an embodiment of the present invention and specific examples thereof.

9 is a flowchart schematically illustrating a control method of an image processing apparatus for correcting a lens shading phenomenon according to an exemplary embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

3: power switch 10: lens unit

11: lens driver 13: shutter release button

14: Mode dial function buttons 16: External interface

17: Viewfinder 20: Aperture

21: aperture driver 30: imaging device

31: imaging device control section 33: auto-focus lamp

34: Flash standby lamp 35: Display panel

36: Manual-Focusing / Delete / Collapse Button

37: Manual-Adjust / Play / Stop / Enlarge Button

39W: wide angle-zoom button 39T: telephoto-zoom button

40: A / D conversion section 42: playback mode button

50: digital signal processor 60: memory

70: recording / reading control unit 80: recording medium

200: control panel SP: speaker

300: main body 301: information delivery unit

302: correction unit

Claims (8)

A lens unit in which brightness information corresponding to each area of an image formed during imaging is stored; And An information transfer unit connected to the lens unit to receive the brightness information stored in the lens unit, and a correction unit configured to uniformly correct brightness for each area of the image by receiving the brightness information from the information transfer unit. An image processing apparatus comprising a main body. According to claim 1, And the lens unit selects and replaces one of a kind having different brightness information. According to claim 1, The lens unit includes a memory for storing the brightness information corresponding to each area of the image formed during imaging. The method of claim 3, wherein And the memory is a ROM or flash memory. Coupling a lens unit to a body part, in which brightness information corresponding to each area of an image formed during imaging is stored; Acquiring the brightness information from the main body by the lens unit; and And uniformly correcting brightness of each area of an image by using brightness information obtained from the main body. The method of claim 5, And initializing the main body before coupling the lens unit to the main body. The method of claim 5, And the lens unit selects and replaces one of a kind having different brightness information. The method of claim 5, And the lens unit has a memory in which brightness information corresponding to each area of an image formed during imaging is stored.

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