KR20100029285A - A projector and a method of image revision - Google Patents

Abstract

PURPOSE: An image correcting projector and an image correcting method thereof are provided to more correctly amend an image by adjusting a level of a test pattern or an iris of a camera lens according to influence of external lighting. CONSTITUTION: An image correcting projector comprises the following: a test image producing part(10) producing a test image for correcting an image according to external environment; a display driver part(20) converting the test image into a signal format according to kinds of a panel; a camera part(30) acquiring luminance of the test image; and a control part(40) setting a gain value for correcting images when the luminance of the test image is gained on a screen.

Description

Image correction Projector and image correction method

The present invention relates to an image correction projector and an image correction method for compensating the influence of external light.

Recently, display devices are becoming lighter and thinner, as well as larger screens, and among various display devices, a projector has been in the spotlight as a display device implementing a large screen of 100 inches or more.

Such projectors include light containing image signals generated using micro devices such as transmissive liquid crystal display (LCD) panels, reflective liquid crystal on silicon (LCoS) panels, and digital micromirror device (DMD) panels. As a device projecting onto a screen to form a screen, it can be classified into a single plate type, two plate type, and three plate type projectors depending on how many micro elements are used.

In the case of the three-panel projector, the color separation into red (R), green (G), and blue (B) colors is spatially separated to illuminate three micro-elements. It is a method that separates space and time and illuminates two micro devices, and a single-plate projector is a method that separates colors in time so that it is illuminated on one micro device.

According to an exemplary embodiment of the present invention, an aperture of a camera for acquiring image information reflected on a screen according to external illumination is adjusted, and image correction may be performed using image information obtained through the aperture adjustment.

In addition, in the present invention, by adjusting the level of the test pattern in accordance with the influence of the external lighting, it is possible to compensate for a more accurate R, G, B ratio.

 The problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above may be clearly understood by those skilled in the art from the following description. There will be.

An image correction projector according to an embodiment of the present invention includes a test image generator for generating a test image for image correction according to an external environment; A display driver for converting the generated test image into a signal format according to a type of panel; A camera unit obtaining brightness information of the test image projected on a screen; And a controller configured to set a gain value for image compensation according to the influence of external light by changing the brightness information acquisition condition of the test image when acquiring brightness information of the test image projected on the screen by the camera.

In addition, the image correction method of the image correction projector according to the first embodiment of the present invention comprises the steps of generating a first test image of a black level and a second test image of a specific level; Obtaining brightness information of the first test image and the second test image projected on the screen; Comparing a difference value of brightness information of the obtained first and second test images with a preset reference value; And setting a gain value for compensating the R, G, and B ratios according to the influence of external light according to the comparison result.

In addition, the image correction method of the image correction projector according to a second embodiment of the present invention includes the steps of generating a test image of a specific level for image correction according to the influence of external light; Photographing the generated test image based on a preset shooting range to obtain brightness information; Comparing the obtained brightness information with a preset reference value; And setting a gain value for compensating the R, G, and B ratios according to the influence of external light according to the comparison result.

Image correction projector and image correction method according to an embodiment of the present invention by adjusting the aperture of the camera or the level of the test pattern in accordance with the influence of external lighting, to perform a more accurate image correction to provide the user with an image of the optimum image quality It can work.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the spirit of the present invention is not limited to the embodiments presented, and other embodiments included within the scope of other inventive inventions or the scope of the present invention can be easily made by adding, changing, or deleting other elements. I can suggest.

The term used in the present invention is selected as a general term widely used as possible at present, but in certain cases there is also a term arbitrarily selected by the applicant, in which case the meaning is described in detail in the description of the invention, the name of a simple term It should be clear that the present invention is to be understood as a meaning of terms.

1 is a block diagram showing a configuration of an image correction projector according to an embodiment of the present invention, FIG. 2 is a view for explaining a shooting range of an image correction projector according to a second embodiment of the present invention, and FIG. 4 is a flowchart illustrating an image correction method of an image correction projector according to a first embodiment of the present invention. FIG. 4 is a flowchart illustrating an image correction method of an image correction projector according to a second embodiment of the present invention. to be.

As illustrated in FIG. 1, an image correction projector according to an embodiment of the present invention may include a test image generator 10 generating a test image for obtaining image projection state information according to a projection environment, and the generated test image. A display driver 20 for converting to a signal format according to the type of panel, a camera unit 30 for obtaining brightness information of the test image projected onto the screen 100, and a screen through the camera unit 30. And a control unit 40 for setting the gain value for image compensation according to the influence of external light by changing the brightness information acquisition condition of the test image when acquiring the brightness information of the test image projected on the target image.

Herein, the condition for acquiring the brightness information of the test image according to the first embodiment of the present invention is a condition for varying the brightness of the test image, which is a reference for setting a gain value for R, G, and B ratio compensation according to the influence of external light. According to the second embodiment of the present invention, the brightness information acquisition condition of the test image is a condition for varying a shooting range of the test image, which is a reference for setting a gain value for R, G, and B ratio compensation according to the influence of external light. .

Hereinafter, the operation of the image correction projector according to an embodiment of the present invention will be described.

First, the operation of the image correction projector according to the first embodiment of the present invention will be described.

Here, the display panel basically has a fixed image resolution, whereas the input signal comes in image formats of various resolutions. In this case, a block that changes the size of the input signal to match the image resolution of the panel is a scaler block (not shown).

In addition, there are various types of display panels such as LCD, DLP, LCOS, etc. In order to display an image on the panel, it is necessary to convert the image signal into a unique signal format suitable for the panel.

The display driver 20 is responsible for converting an image signal into a unique signal format suitable for the display panel.

In addition, the controller 40 is responsible for controlling the operation of the scaler (not shown) and the display driver 20.

In addition, the test image generating unit 10 generates a test image for detecting how much change occurs in the image actually displayed according to the current external environment.

In this case, the test image generator 10 first generates a first test image of a full black level, and then generates a second test image of a specific level, and according to a control signal of the controller 40 to be described later. Increase the level of the second test image.

The camera unit 30 obtains brightness information of the test image generated through the test image generator 10 and projected onto the screen 100.

That is, the camera unit 30 captures the generated first test image to obtain first brightness information accordingly, and captures the generated second test image to acquire second brightness information accordingly.

The controller 30 analyzes the first brightness information and the second brightness information acquired through the camera unit 30, and sets a gain value for R, G, B ratio compensation according to external light influence.

In this case, the controller 30 first determines how much external light is present using the obtained first brightness information.

That is, the most accurate pattern for detecting external light is a full black pattern, and accordingly, current external light information is identified using first brightness information according to the generated first test image.

The controller 40 analyzes the difference between the obtained second brightness information and the first brightness information, and compares the difference between the analyzed second brightness information and the first brightness information with a preset reference value. do.

Here, the reference value means a difference value between brightness information according to the second test image and brightness information according to the first test image under a normal condition.

Here, the normal condition is because the R, G, B ratio is most accurately matched in the normal dark condition, the reference value is set to the experimental value obtained through the experiment in the dark room.

Subsequently, when the difference value between the second brightness information and the first brightness information is smaller than the reference value, the controller 40 increases the brightness of the second test image by a predetermined level.

That is, the difference between the second brightness information and the first brightness information is smaller than the reference value indicates that the brightness of the first test image is increased from the normal brightness in the dark condition according to the current external light level, or It means that the brightness is lower than the brightness in the dark conditions.

However, in the related art, by setting a gain value for R, G, and B ratio compensation based on the brightness change of the acquired second test image regardless of external light according to actual field conditions, an accurate gain value is not set. There was a problem.

Accordingly, in the present invention, the brightness of the second test image, which is a reference for setting the gain value for the RGB ratio compensation, is changed according to the degree of external light so that the gain value for more accurate R, G, B ratio compensation can be set. do.

That is, for example, the brightness at dark is 1 cd / m, the brightness at 5cd / m and the brightness at a specific level is 30, 60, 10 cd / m, respectively. When it is dark, the ratio of R, G, and B is 30:60:10, which is normal, but when it is bright, it is (30 + 5) / 5: (60 + 5) / 5: (10 + 5) / 5. Therefore, R, G, B gain values should be set differently depending on the external light.

In addition, in order to set a gain value for more accurate R, G, and B ratio compensation, the level of the test image, which is a reference for setting the gain value, is varied according to the current external light level.

Accordingly, the controller 40 sets a gain value for compensating the R, G, and B ratios based on the brightness information of the second test image that is changed according to the influence of the external light.

That is, the ratio of R, G, and B determined to be optimal under dark conditions is 3: 6: 1, and accordingly, the ratios of R, G, and B according to the brightness information of the second test image are the reference R, G, Set the gain values of R, G, and B to match the B ratio.

As described above, the image correction projector according to the first embodiment of the present invention may adjust the level of the test pattern according to the influence of external illumination, thereby providing more accurate image correction to provide the user with an image of optimum quality.

In addition, the operation of the image correction projector according to the second embodiment of the present invention is as follows.

In the image correction projector according to the second embodiment of the present invention, the same configuration and the same operation part as those of the image correction projector according to the first embodiment will be omitted.

The test image generator 10 generates a test image of a specific level.

The camera unit 30 obtains brightness information of the test image projected on the screen based on a preset shooting range.

Here, the photographing range is changed by adjusting the aperture attached to the camera unit 30.

The controller 40 compares the brightness information obtained through the camera unit 30 with a preset reference value and sets a gain value for the R, G, B ratio compensation accordingly.

In this case, the controller 40 selectively changes the photographing range of the camera unit 30 according to the degree of external light to set a gain value for more accurate R, G, and B ratio compensation.

That is, the gain value for the R, G, B ratio compensation is set according to the brightness information of the test image acquired based on the fixed shooting range.

However, the brightness information of the acquired specific shooting range is changed according to the degree of external light, and accordingly, a gain value for accurate R, G, and B ratio compensation cannot be set.

Therefore, in the second embodiment of the present invention, the shooting range is changed according to the degree of external light, and the gain value for the R, G, B ratio compensation is set according to the current degree of external light.

That is, as shown in FIG. 2, initially, only brightness information of an image belonging to the preset first shooting range 110 is obtained from an image projected through the screen 100, and compared with the reference value, and the obtained brightness is obtained. If the information is smaller than the reference value, it is determined that the current degree of external light is severe, and the shooting range is increased to the second shooting range 120 or the third shooting range 130.

In other words, when the obtained brightness information is smaller than a preset reference value, a difference occurs in the values of the R, G, and B ratios for the image projected on the screen. The reason for this is that the amount of light entering by the aperture adjustment is small, so the amount of light entering the camera is small, so that normal compensation is not achieved when adjusting the color.

Therefore, according to the obtained brightness information, the aperture range of the camera unit 30 is adjusted to change the photographing range, and accordingly, a gain value for accurate R, G, and B ratio compensation is set.

As described above, the image correction projector according to an exemplary embodiment of the present invention may provide a user with an image having an optimal image quality by performing a more accurate image correction by varying a shooting range according to an aperture adjustment of a camera according to the influence of external lighting.

In the image correction method of the image correction projector according to the first embodiment of the present invention configured as described above, as shown in FIG. 3, a first test image having a black level is first generated (S10).

Subsequently, first brightness information of the first test image projected on the screen is obtained (S20).

In addition, the degree of external light according to the current external environment is determined based on the first brightness information of the first test image (S30).

Next, a second test image of a specific level is generated (S40). That is, a second test image of 128 levels is generated.

In operation S50, second brightness information regarding the generated second test image is obtained.

Subsequently, it is determined whether the difference value between the obtained second brightness information and the first brightness information is greater than a preset reference value (S60).

In addition, when the difference between the second brightness information and the first brightness information is greater than a preset reference value, the determination result (S60), a gain value for the R, G, B ratio compensation based on the obtained second brightness information. Set (S70).

In addition, when the difference value between the second brightness information and the first brightness information is smaller than a preset reference value (S70), the existing brightness level of the second test image is increased by 10 levels.

As described above, in the image correction method of the image correction projector according to the first embodiment of the present invention, by adjusting the level of the test pattern according to the influence of external illumination, the image correction may be performed more precisely to provide the user with an image of optimal quality. Can be.

In addition, the image correction method of the image correction projector according to the second embodiment of the present invention configured as described above, as shown in Figure 4, first generates a test image of a specific level (S100).

Subsequently, brightness information of the test image projected on the screen is acquired according to a preset shooting range (S110).

In operation S120, it is determined whether the obtained brightness information is greater than a preset reference value.

Subsequently, when the brightness information is greater than a preset reference value, the determination result (S120) sets a gain value for R, G, B ratio compensation based on the obtained brightness information (S130).

In addition, if the brightness information is smaller than a predetermined reference value (S120), the set photographing range is increased to return to the step S110 (S140).

As described above, the image correction method of the image correction projector according to an embodiment of the present invention varies the shooting range according to the aperture adjustment of the camera according to the influence of external lighting, thereby providing more accurate image correction and providing the user with an image of optimum quality. can do.

1 is a block diagram showing the configuration of an image correction projector according to an embodiment of the present invention.

2 is a view for explaining a shooting range of the image correction projector according to a second embodiment of the present invention.

3 is a flowchart illustrating a step-by-step image correction method of an image correction projector according to a first embodiment of the present invention.

4 is a flowchart illustrating a step-by-step image correction method of an image correction projector according to a second embodiment of the present invention.

<< Explanation of symbols for main part of drawing >>

10: test image generator 20: display driver

30: camera unit 40: control unit

Claims (9)

A test image generator which generates a test image for image correction according to an external environment; A display driver for converting the generated test image into a signal format according to a type of panel; A camera unit obtaining brightness information of the test image projected on a screen; And, And a controller configured to set a gain value for image compensation according to the influence of external light by changing a condition of acquiring brightness information of the test image when acquiring brightness information of the test image projected on the screen by the camera. The method of claim 1, And the controller changes the brightness of the test image as a reference for setting a gain value for R, G, and B ratio compensation according to the influence of external light. The method of claim 1, And the controller is configured to vary a shooting range of the test image as a reference for setting a gain value for R, G, and B ratio compensation according to the influence of external light. Generating a first test image of a black level and a second test image of a specific level; Obtaining brightness information of the first test image and the second test image projected on the screen; Comparing a difference value of brightness information of the obtained first and second test images with a preset reference value; And, And setting a gain value for compensating the R, G, and B ratios according to the influence of external light according to the comparison result. The method of claim 4, wherein And increasing the level of the second test image by a predetermined level when the difference value of the brightness information of the first and second test images is smaller than a preset reference value. The method of claim 5, Setting the gain value for compensating the R, G, B ratio is And setting a gain value for compensating the R, G, and B ratios based on the brightness information of the second test image whose level increases according to the comparison result. Generating a test image of a specific level for image correction according to the influence of external light; Photographing the generated test image based on a preset shooting range to obtain brightness information; Comparing the obtained brightness information with a preset reference value; And, And setting a gain value for compensating the R, G, and B ratios according to the influence of external light according to the comparison result. The method of claim 7, wherein And changing the preset shooting range when the obtained brightness information is smaller than a preset reference value. The method of claim 8, Setting a gain value for compensating the R, G, and B ratios And setting a gain value for compensating the R, G, and B ratios by using brightness information of a specific shooting range having brightness information greater than the preset reference value.

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