KR100702961B1 - Apparatus for image signal calibration, apparatus for image output, and digital camera - Google Patents

Abstract

The image of the digital camera is displayed on the television monitor in color scheme as intended by the photographer.

An image signal calibration apparatus capable of calibrating an image displayed on a television monitor, comprising: a reference signal output section for outputting a reference signal to an external display device; An imaging unit which picks up an image displayed on the display device based on the reference signal; Analyzing the image signal obtained from the image pickup unit, obtaining a color conversion matrix from the obtained image signal, until the adjustment performance obtained from the color signal of the test image and the color signal of the output image is smaller than a predetermined target value An analyzer configured to perform calibration and to generate calibration values for displaying a general image signal in a desired state on the display device; A storage unit for storing the calibration value; And a correction unit which reads out the calibration value stored in the storage unit and corrects the general image signal.

Description

Apparatus for image signal calibration, apparatus for image output, and digital camera

1 is a block diagram showing a schematic configuration of an image calibration apparatus constructed in accordance with an embodiment of the present invention.

2 is a flowchart showing a calibration process pre-processing process according to the embodiment.

3 is a production process chart showing a calibration process in the same embodiment.

4 is a process explanatory diagram for obtaining a calibration value and ΔE value in the embodiment.

<Brief description of the major symbols in the drawings>

100: image calibration device 110: display device

120: output unit 130: test image

140: photographing unit 150: analysis unit

160: storage unit 170: correction unit

(Patent Document 1) Japanese Patent Application Laid-Open No. 10-260109

(Patent Document 2) Japanese Patent Application Laid-Open No. 2003-66539

The present invention relates to an image calibration device, an image output device, and a digital camera.

Electronic still cameras and video cameras such as digital cameras often use sRGB (IEC61966-2-1) or AdobeRGB (DCF optional color space JEITA CP-3461), which is a standard color space, as a color space. As a method of viewing an image picked up by a digital camera or the like, a method of printing on a paper medium by a printer is prevalent. Since the printer expresses the sRGB or AdobeRGB space, the printer is well matched with the digital camera and can be printed without distorting the color space of the image captured by the digital camera. In addition, a method of displaying an image captured by a digital camera or the like on a PC monitor has also become popular. Since the PC monitor expresses the color space of sRGB, it is well matched with a digital camera and can be displayed without distorting the color space of the image captured by the digital camera.

BACKGROUND ART A television monitor is an image display device that is widely used in general homes. As a television monitor moves from a conventional CRT to a new method such as liquid crystal, PDP, OLED, etc., digitalization also progresses, and an environment in which an image can be displayed by directly connecting a digital camera or the like is prepared.

Television monitors, like PC monitors, use sRGB as the standard color space. However, in the case of television monitors, color and brightness may be corrected with respect to the original sRGB in order to create a clearer picture. In such a case, displaying the image of the digital camera directly on the television monitor cannot accurately reflect the photographer's shooting intention.

Moreover, Japanese Patent Laid-Open No. 2003-66539 which discloses a color management system of a photo processing apparatus can be illustrated as a prior art which performs calibration when converting the image formed in the positive film into a digital image in connection with this invention. . Further, Japanese Patent Application Laid-open No. Hei 10-260109 is known as a method of imaging a screen displayed on a television monitor to evaluate image quality. However, none of the prior arts assumes that the image of the digital camera is displayed on the television monitor, and is not applicable to the calibration of the digital image displayed on the television monitor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems and various problems, and provides a novel improved image signal calibration device, image output device, and digital camera capable of calibrating an image displayed on a display device such as a television monitor. It is aimed.

In order to solve the above problems, the present invention provides an image signal calibration apparatus capable of calibrating an image displayed on a television monitor, comprising: a reference signal output unit for outputting a reference signal to an external display device; An imaging unit which picks up an image displayed on the display device based on the reference signal; Analyzing the image signal obtained from the image pickup unit, obtaining a color conversion matrix from the obtained image signal, until the adjustment performance obtained from the color signal of the test image and the color signal of the output image is smaller than a predetermined target value An analyzer configured to perform calibration and to generate a calibration value for displaying a general image signal in a desired state on the display device; A storage unit for storing the calibration value; And a correction unit which reads out the calibration value stored in the storage unit and corrects the general image signal. According to such a configuration, since a calibration is performed to display a general image signal in a desired state on the display device based on an image actually displayed on a display device such as a television monitor, the image display can be performed as intended by the photographer or user. have.

The calibration value may relate to a color space and / or a brightness space of the display device. The reference signal can be displayed on the display device with an analysis pattern. Correction may be performed at the time of imaging or at the time of outputting a general image signal.

According to another aspect of the present invention to solve the above problems, a reference signal output unit for outputting a reference signal to an external display device, and an image signal obtained by imaging the image displayed on the display device based on the reference signal An analysis unit for generating a calibration value for displaying the general image signal in a desired state on the display device, a storage unit for storing the calibration value, a correction unit for reading the calibration value stored in the storage unit and correcting the general image signal; And an image output section for outputting a corrected general image signal. Even in such a configuration, since a calibration is performed to display a general image signal in a desired state on the display device based on an image actually displayed on a display device such as a television monitor, the image display can be performed as intended by the photographer or the user. .

The calibration value may relate to a color space and / or a brightness space of the display device. The reference signal can be displayed on the display device with an analysis pattern. Correction can be performed at the time of outputting a general image signal.

According to still another aspect of the present invention for solving the above problems, a reference signal output unit for outputting a reference signal to an external display device, an imaging unit for imaging an image displayed on the display device based on the reference signal, and an imaging unit An analysis unit for generating a calibration value for analyzing the image signal obtained by the display and displaying the general image signal in a desired state, a storage unit for storing the calibration value, and a calibration value stored in the storage unit. There is provided a digital camera comprising a correction unit for correcting a general image signal. Even with such a configuration, since a calibration is performed to display a general image signal in a desired state on the display device based on an image actually displayed on a display device such as a television monitor, the image display as intended by the photographer or the user can be performed. have.

The calibration value may relate to a color space and / or a brightness space of the display device. The reference signal can be displayed on the display device with an analysis pattern. Correction may be performed at the time of imaging or at the time of outputting a general image signal.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described in detail, referring an accompanying drawing. In addition, in this specification and drawing, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol about the component which has substantially the same functional structure.

1. Device configuration

In FIG. 1, the schematic structure of the image calibration apparatus 100 which concerns on this embodiment is shown. As illustrated, the image calibrating apparatus 100 may include a reference signal output unit 120 that outputs a reference signal RS to an external display device 110, and a display device 110 based on the reference signal RS. An imaging unit 140 for imaging the analysis pattern (test chart and / or angle of view adjustment image) 130 displayed on the screen, and an image signal ISr obtained by the imaging unit, to generate a calibration value CV. A general image signal IS for reading the calibration value CV from the storage unit 160, the storage unit 160 for storing the calibration value CV, and displaying the calibration value CV from the storage unit 160. It is mainly composed of a correction unit 170 for converting ().

The display apparatus 110 is comprised with the conventional type monitors, such as CRT, a liquid crystal display, panel type monitors, such as PDP and OLED. The display device 110 adopts sRGB as the standard color space, and displays the image by correcting the color or the brightness so that a clear image is obtained by an internal circuit. The output unit 120 may output the reference signal RS to the display device 110 in a wired or wireless manner. The imaging unit 140 may adopt a configuration in which a digital image signal such as a CCD or a CMOS can be directly obtained, or a configuration in which an analog signal is converted into a digital signal by an AD converter. The analysis unit 150 or the correction unit 170 is configured by driving the microprocessor with a predetermined program. The storage unit 160 is composed of an internal memory device such as DRAM or EEPROM. The calibration value CV obtained by the analysis unit 150 is a value that can grasp the distortion from the color space or brightness space distorted by the display device 110 and obtain an image signal as intended by the photographer or the user. .

In the above, the schematic configuration in which the present invention is applied to the image calibration device 100 is shown. However, the present invention displays the image signal ISc in which the image signal IS is optimized based on the calibration value CV. It can be configured as an image output device for outputting. The image output device includes an image output unit that outputs the corrected general image signal to the display device 110 in addition to the components of the image calibration device 100. As illustrated in FIG. 1, the image output unit may be configured integrally with the reference signal output unit 120, or may be configured separately from the image output unit and the reference signal output unit. When the present invention is constituted by an image display device, the imaging unit 140 is not necessarily required, and the imaging unit 140 may be configured to acquire the image signal ISr from the separately configured imaging unit 140 through signal lines or the like.

Moreover, this invention can also be comprised with the digital camera or video camera provided with the image calibration apparatus 100. FIG. In addition, in this specification, a claim, the summary, and the drawing, when referring only to a digital camera, it shall also include imaging devices other than a video camera.

In addition, in the above configuration, the display device 110 is configured to be an external one, but the display device 110 such as an external television monitor and the image calibration device 100 composed of a digital camera are performed to perform a calibration operation. It is for demonstrating this invention based on the form. When comprised with an image output apparatus, the structure assembled with the display apparatus 110 can also be employ | adopted. In this case, a configuration may be adopted in which the display screen of the reference signal RS acquired by an imaging device such as an external digital camera is packed from the digital camera to the image calibration device of the display device 110.

2. Calibration process

Next, a calibration operation of the image calibration device, the image output device, or the digital camera configured as described above will be described with reference to FIGS.

2.1 shearing treatment

First, the calibration process shearing process which concerns on this embodiment is demonstrated, referring FIG.

In order to perform the calibration process, the digital camera (image calibration device 100) and the display device 110 are connected (S21). The connection means is not tied to wired or wireless. In addition, a suitable one can also be adopted for the communication protocol.

Next, the profile creation of the image display apparatus 110 is instructed (S22). In this way, the test chart and / or the angle of view adjustment image are sent from the image calibration device 100 to the image display device 110.

Next, the digital camera is automatically changed to the optimal condition (S23). The conditions are set to Strobe Off, Optical Zoom to a suitable position, AWB to Off, AE, AF to Auto, or an optimum condition for shooting a TV monitor.

Subsequently, a message for setting the angle of view is sent from the digital camera to the user, and the angle of view adjustment is performed (S24, S25, S26). Instructions are displayed in a preview (e.g., displaying a moving picture on an LCD monitor) along with a test chart or separately displaying an angle of view adjustment image (e.g., an image with four angles indicated by four corners). Prompt to adjust the camera position to fit within the frame. The angle of view adjustment detects the position of the angle bracket, detects how to enter the angle of view with respect to pitch, row, and yaw, and sends a countermeasure to the user as a message. If the condition is met, a message is sent to the user to wait for an instruction to start calibration.

2.2 Calibration Process

Next, a calibration process according to the present embodiment will be described with reference to FIG. 3.

First, the digital camera and the display device 110 are connected by a wired cable such as a USB cable or an AV cable, or a wireless LAN, and the screen and the camera are arranged in correspondence with each other, and the angle of view is adjusted by the shearing process shown in FIG. (S31).

Subsequently, the user is instructed to start calibration in accordance with the user interface displayed on the LCD monitor of the digital camera (S32).

On the screen of the display device 110 such as a television monitor, a test image is displayed based on the reference signal sent from the image calibrating device of the digital camera (S33). As a test image, a color patch, a gradient chart, etc. can be employ | adopted, for example.

Next, the displayed test image is photographed (S34). At this time, the angle of view, size, and the like are adjusted inside the camera as necessary.

Next, a calibration process is performed according to the process mentioned later with reference to FIG. 4 (S35). The calibration process can be performed, for example, by color conversion matrix and gamma correction.

Next, a test image to which the calibration data calculated in step S35 is applied is displayed (S36).

The test camera photographs the test image after correction in the digital camera (S37), and measures the adjustment performance of the captured image data and the test image (S38). For example, the adjustment performance can use the ΔE value described later with reference to FIG. 4.

In this way, the calculated calibration value is stored (S39), and the processes from S33 to S39 are repeated until the ΔE value is smaller than the target value T1, and when the ΔE value is smaller than the target value T1. The process ends (S40).

Next, with reference to FIG. 4, calibration value calculation and (DELTA) calculation in the calibration process based on this embodiment are demonstrated.

First, the color signals Rl, Gl, and Bl of the test image of the color patch are well known with respect to the color (S41). Regarding the color, the color signals R2, G2, and B2 of the output image are values obtained by photographing a test image displayed on the display device 110 such as a television monitor, so that the value is converted into a desired value (S42). .

Subsequently, a matrix satisfying the following formula (1) is obtained by calculation as a calibration value, and this matrix is used as a calibration value (S43).

‥‥(1)

‥‥(One)

 Subsequently, the color signal of the test image and the color signal of the output image are mapped to three coordinate value (X, Y, Z) spaces, and are respectively set to (X1, Y1, Z1), (X2, Y2, Z2) (S44, S45). Next, color difference (DELTA) E is calculated from these three coordinate values, for example by following formula (2) (S46).

‥‥(2)

‥‥(2)

The calibration value thus obtained is assigned to an appropriate name for each display device 110 such as a television monitor and stored in the storage unit 160.

3. Shooting / display by correction value

The calibration values obtained as described above are stored in the storage unit 160, and are read from the storage unit 160 when the image signals photographed with the digital camera are displayed on the display device 110 such as a television monitor. Used to calibrate.

Further, the calibration process may be performed every time a general image signal is output from the image calibration apparatus 100 to the display apparatus 100. The calibration process may be added at the time of shooting with a digital camera, and the corrected image signal may be stored. The display device 100 may be configured to directly output the corrected image signal to the display device 100.

As described above, according to the configuration of the image calibration device, the image output device, or the digital camera according to the present embodiment, a general image signal is displayed on the display device in a desired state based on the image actually displayed on the display device such as a television monitor. Since calibration is performed, image display can be performed as intended by the photographer or the user.

As described above, according to the present invention, since a calibration is performed to display a general image signal in a desired state on the display device based on an image actually displayed on a display device such as a television monitor, an image as intended by the photographer or the user. The display can be performed.

Although the present invention has been described with reference to the embodiments illustrated in the accompanying drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible therefrom. . Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims (5)

An image signal calibration device capable of calibrating an image displayed on a television monitor, A reference signal output unit configured to output a reference signal to an external display device; An imaging unit which picks up an image displayed on the display device based on the reference signal; Analyzing the image signal obtained from the image pickup unit, obtaining a color conversion matrix from the obtained image signal, until the adjustment performance obtained from the color signal of the test image and the color signal of the output image is smaller than a predetermined target value An analyzer configured to perform calibration and to generate calibration values for displaying a general image signal in a desired state on the display device; A storage unit for storing the calibration value; And And a correction unit that reads the calibration value stored in the storage unit and corrects the general image signal. The method of claim 1, And the calibration value relates to a color space and / or a brightness space of the display device. The method according to claim 1 or 2, And the reference signal causes an analysis pattern to be displayed on the display device. The method according to claim 1 or 2, And the correction is performed at the time of imaging. The method according to claim 1 or 2, And the correction is performed at the time of outputting the general image signal.

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