KR101477533B1 - Method and apparatus for compensating an image - Google Patents

Abstract

The present invention relates to a method and an apparatus for compensating an image to be displayed according to external light, and a method of compensating an image to be displayed according to external light according to an embodiment of the present invention, Mode is selected, control information for adjusting an image according to the selected reproduction mode is generated, and the image is compensated according to the control information, so that complicated calculation processing is not performed and additional hardware for measuring external light is not provided There is an effect that the image to be displayed can be conveniently reproduced regardless of the place.

Playback mode, compensation, brightness, saturation

Description

TECHNICAL FIELD The present invention relates to an image compensation method and apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image compensation method and apparatus, and more particularly, to a method and apparatus for compensating an image to be displayed according to external light and a digital photographing apparatus using the same.

2. Description of the Related Art Recently, photographing systems using photographing apparatuses have been widely used, and home video cameras and digital still cameras are widely used as typical examples of such photographing systems. In addition, according to the development of a wireless communication network, images photographed through such a photographing system can be reproduced at any time, and mobile phones, PDAs, MP3s, PMPs, and navigation systems are widely used as devices for reproducing images.

On the other hand, when viewing the display indoors, the user is able to see the image similar to the case of viewing the image in the dark room because it is not greatly affected by the surrounding environment. However, if the image viewed in the indoor environment is viewed in the outdoor environment, the same image is recognized differently. This is because the sensitivity curve of the human eye changes according to the brightness of the surroundings, and the ambient light source affects the standard color stimulation of the display. As a result, it looks darker and has lower saturation than when viewed indoors. For example, when an image photographed from a digital photographing apparatus is reproduced in a strong sunlight, the display frequently reflects light and the user can not perceive it properly or not at all.

In order to solve the above-mentioned problem, there is an image compensating technique which is provided with a separate sensor for measuring the brightness of the external illumination and compensates the image reproduced by calculating the human vision and flare, that is, the amount of reflected light. However, it has a lot of computation steps, but it has a disadvantage that the complexity and fine calculation process is less accurate than the amount of reflected light.

Another technique is a real-time color correction method of a camera according to a lighting condition, in which not only the color but also the brightness change as the lighting conditions are changed. In addition to performing the correction for the color without considering the brightness, There are many disadvantages.

In addition, although the above-described two prior art techniques have a common point of measuring the brightness of external illumination and generating an image to be compensated on the display of the camera using the measured brightness, The amount of reflected light is so large that there is a problem that it is difficult for the human eye to perceive the image as the original image.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the related art, and it is an object of the present invention to provide an image compensation method according to external light, which does not require a separate sensor for measuring external illuminance, And an apparatus.

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

According to an aspect of the present invention, there is provided a method of compensating an image to be displayed according to external light, the method comprising: selecting a reproduction mode for displaying the image according to a user's selection; Generates control information for controlling an image, and compensates the image according to the control information.

Preferably, the control information includes control information for controlling the brightness of the image and control information for controlling the saturation of the image.

Preferably, the reproduction mode includes at least one reproduction mode according to the intensity of the external light.

Preferably, the control information for adjusting the brightness and the control information for adjusting the saturation are determined according to the respective reproduction modes.

According to another aspect of the present invention, there is provided an apparatus for compensating for an image to be displayed according to external light, comprising: a mode selection unit for selecting a reproduction mode for displaying the image according to a user's selection; A control unit for generating control information for controlling the image, and an image compensator for compensating the image according to the generated control information.

Preferably, the control information includes control information for adjusting the brightness of the image and control information for adjusting the saturation of the image, and the image compensator may adjust the brightness of the image according to the control information for adjusting the brightness of the image. And a chroma compensator for compensating chroma of the image according to control information for controlling chroma of the image.

Preferably, the reproduction mode includes at least one reproduction mode according to the intensity of the external light.

Preferably, the control information for adjusting the brightness and the control information for adjusting the saturation are determined according to the respective reproduction modes.

According to another aspect of the present invention, there is provided a digital photographing apparatus for compensating an image to be displayed according to external light, comprising a mode selection unit for selecting a reproduction mode for displaying an image photographed by the digital photographing apparatus, A controller for generating control information for adjusting the brightness and chroma of the image according to the reproduction mode selected from the mode selector, and an image compensator for compensating the image according to control information from the controller.

According to another aspect of the present invention, there is provided a recording medium on which a program for causing the computer to execute the above methods is recorded.

According to an embodiment of the present invention, there is provided a method of compensating an image to be displayed according to external light, comprising: selecting a reproduction mode for displaying an image according to a user's selection; generating control information for controlling an image according to a reproduction mode; The image is compensated according to the information, so that the image to be displayed can be conveniently reproduced regardless of the place, without requiring a complicated calculation process and without any additional hardware for measuring external light.

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

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

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

1, the digital camera 100 includes an optical unit 10, an optical drive unit 11, an image pickup device 15, an image pickup device control unit 16, an operation unit 20, a mode selection unit 21, A program storage unit 30, a buffer storage unit 40, a data storage unit 50, a display control unit 60, a data driving unit 61, a scan driving unit 63, a display unit 65, , 70).

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

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

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

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

The mode selection unit 21 provides a playback mode for displaying an image captured by the user or an image stored when the user views the stored image. Here, the reproduction mode may provide a plurality of reproduction modes, for example, in a case where the sunlight is strong, and a reproduction mode in which the sunlight is weak. Further, it is also possible to separately provide the reproduction mode in addition to the strongness of sunlight and the intensity of external illumination. The mode selection unit 21 may be provided on the back of the digital photographing apparatus 100 with a specific key button or a menu screen. Alternatively, the playback mode may be switched by selecting another playback mode even in the midst of the user viewing and playing back the video.

In the preferred embodiment of the present invention, the operation unit 20 and the mode selection unit 21 are separately displayed. However, it goes without saying that the operation unit 20 may include the function of the mode selection unit 21 described above.

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

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

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

DSP 70 will be described with reference to FIG.

Referring to FIG. 2, the DSP 70 includes a control unit 71, a video signal processing unit 72, and an image compensation unit 73.

The control unit 71 controls the overall operation of the DSP 70. In the preferred embodiment of the present invention, the control unit 71 generates control information for adjusting an image to be displayed in accordance with the reproduction mode provided from the mode selection unit 21 shown in FIG. Here, the control information is information on how much the brightness and saturation of the image to be reproduced are compensated for. For example, when the user selects the 'weak sunlight mode' when the playback mode is 'weak sunlight mode' and 'strong sunlight mode', the control unit 71 determines that the brightness is increased by 10% And generates the control information which increases the saturation by 40% as compared with the original image. In addition, when the user selects 'strong sunlight mode', the control unit 71 generates control information for increasing brightness by 20% as compared with the original image, and generates control information for increasing the saturation by 80% as compared with the original image. Here, it is explained that the brightness is increased by a specific ratio, 10% or 20% in accordance with the reproduction mode. However, the present invention is not limited to such a ratio but may be determined experimentally according to external light or determined by an optimum ratio. The same is true for the increasing rate of saturation. Accordingly, it is possible to compensate for the brightness and the saturation by regulating the brightness or the saturation of the image to be reproduced according to the external light to be lower than that of the original image according to the user's selection.

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

The image compensating unit 73 compensates the image to be reproduced according to the control information provided from the control unit 71. The image compensating unit 73 includes a brightness compensating unit for compensating the brightness of the image according to control information for adjusting the brightness of the image, and a saturation compensating unit for compensating for the saturation of the image according to the control information for controlling the saturation of the image. Conventional image brightness and chroma compensation techniques can be applied to compensation of brightness and chroma of an image, and a detailed description of brightness compensation and chroma compensation will be omitted in the present invention.

Although the image signal processor 72 and the image compensator 73 are separately described in the preferred embodiment of the present invention, the image signal processor 72 can perform the function of the image compensator 73, to be.

3 is a flowchart illustrating an image compensation method according to another embodiment of the present invention.

Referring to FIG. 3, in step 300, when the user wants to reproduce an image or a stored image, the user selects an image reproduction mode according to external light. Here, the reproduction mode may be singular or plural, and the compensation ratio of the set brightness and / or saturation is determined according to each reproduction mode.

In step 302, control information according to the selected reproduction mode is generated. That is, control information for determining a compensation ratio of brightness and / or saturation corresponding to a specific reproduction mode.

In step 304, the brightness and / or saturation of the original image to be reproduced is compensated according to the generated control information. Here, compensation means increasing and decreasing brightness and chroma compared with the original image in accordance with the intensity of external light.

In step 306, the compensated image is reproduced through step 304. Therefore, the resultant image is output with the brightness and saturation adjusted as compared with the original image. Here, the output image is an image in which brightness and saturation are increased by 20% and 80%, respectively, as compared with the original image, when the playback mode selected by the user is the 'strong sunlight mode'. Therefore, even in the environment where strong sunlight shines, the reproduced image can be seen without a big difference from the original image.

Although the image compensation apparatus and compensation method as one component of the digital photographing apparatus 100 have been described in the foregoing description, the image compensation apparatus can be implemented independently, and the image compensation apparatus can be implemented in all devices Can be applied. For example, the present invention can be applied to portable devices including mobile phones, PDAs, MP3Ps, PMPs, and navigation devices.

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

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

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

1 is a schematic block diagram of a digital photographing apparatus 100 according to an embodiment of the present invention.

2 is a schematic block diagram of the digital signal processing unit 70 shown in FIG.

3 is a flowchart illustrating an image compensation method according to another embodiment of the present invention.

Description of the Related Art

100: digital photographing apparatus 21: mode selecting section

71: control unit 73: image compensation unit

Claims (10)

A method of compensating an image to be displayed according to external light, Selecting a playback mode for displaying the image according to a user's selection; Generating control information for controlling the image according to the selected reproduction mode; And And compensating the image according to the control information, In the reproduction mode, And at least one reproduction mode according to the intensity of the external light. The method according to claim 1, The control information includes: And control information for adjusting the brightness of the image and control information for adjusting the saturation of the image. delete The method according to claim 1, Wherein control information for adjusting the brightness and control information for adjusting the saturation are determined according to the respective reproduction modes. A recording medium on which a program for causing a computer to execute the method according to any one of claims 1, 2, and 4 is recorded. An apparatus for compensating an image to be displayed according to external light, A mode selection unit for selecting a reproduction mode for displaying the image according to a user's selection; A control unit for generating control information for controlling the image according to a playback mode selected from the mode selection unit; And And an image compensator for compensating the image according to the generated control information, In the reproduction mode, And at least one reproduction mode according to the intensity of the external light. The method according to claim 6, The control information includes: And control information for controlling brightness of the image and control information for controlling saturation of the image, Wherein the image compensating unit comprises: A brightness compensator for compensating for brightness of the image according to control information for controlling brightness of the image; And And a chroma compensator for compensating chroma of the image according to control information for controlling chroma of the image. delete The method according to claim 6, Wherein control information for adjusting the brightness and control information for adjusting the saturation are determined according to the respective reproduction modes. A digital photographing apparatus for compensating an image to be displayed according to external light, A mode selection unit for selecting a reproduction mode for displaying an image stored in the digital photographing apparatus according to a user's selection; A control unit for generating control information for controlling the brightness and chroma of the image according to the reproduction mode selected from the mode selection unit; And And an image compensator for compensating the image according to control information from the controller, In the reproduction mode, And at least one reproduction mode according to the intensity of the external light.

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