Projection equipment and wall color distortion and brightness correction method for projection equipment

Abstract

The invention relates to projection equipment and a wall color distortion and brightness correction method for the projection equipment, and the method comprises the steps: respectively setting the brightness proportions of R, G and B channels of the projection equipment to be 100%, and then projecting a feature image only containing black and white colors through the projection equipment; selecting a region from the feature image as a correction region; based on the correction area, obtaining average gray values of R, G and B channels corresponding to black and white, calculating a final adjustment proportion of each channel, and performing ray machine chromaticity adjustment; and in combination with parameters output by a camera module in the current projection equipment, a brightness adjustment value is calculated, and light machine brightness adjustment is carried out. According to the invention, correction of color distortion and brightness of the projection equipment is realized.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection device and a method for correcting color distortion and brightness of a wall surface of the projection device. Background Art

[0002] With the development of projection technology, projection has gradually become a widely used multimedia display method. However, in actual use, due to different wall decoration effects of users, the wall color may be different. When the projector image is projected onto walls of different colors, the color of the image superimposed on the wall color will cause color distortion.

[0003] Existing color distortion correction solutions often require an additional color feature image for correction, while brightness correction is often performed through the ambient brightness sensed by the ALS (ambient light sensor). Since the ALS is often installed above or in front of the projector, it has a difference in brightness value from the projected image, so the accuracy is not high. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a projection device and a method for correcting color distortion and brightness of a wall of the projection device.

[0005] The specific plan is as follows:

[0006] A method for correcting color distortion and brightness of a wall of a projection device comprises the following steps:

[0007] S1: After setting the brightness ratios of the three channels R, G, and B of the projection device to 100% respectively, a feature image containing only black and white colors is projected through the projection device;

[0008] S2: Select an area from the feature image as the correction area;

[0009] S3: Get the average grayscale values ​​aveR, aveG, aveB of the three channels of R, G, and B corresponding to all white pixels in the correction area, and use the average grayscale value of the G channel as the average brightness brightness_w corresponding to white;

[0010] S4: Obtain the average grayscale value of the G channel corresponding to all black pixels in the correction area, and use it as the average brightness brightness_b corresponding to black;

[0011] S5: Calculate the brightness difference between white and black: brightness = brightness_w - brightness_b;

[0012] S6: Calculate the current gain value curGain_R of the R channel and the current gain value curGain_B of the B channel;

[0013] curGain_R=1024*aveG / aveR

[0014] curGain_B=1024*aveG / aveB

[0015] Wherein, aveR represents the average gray value of the R channel; aveG represents the average gray value of the G channel; aveB represents the average gray value of the B channel;

[0016] S7: Calculate the initial adjustment ratio of the three channels R, G, and B:

[0017] ratio_R=curGain_R / targetR

[0018] ratio_G=1

[0019] ratio_B = curGain_B / targetB

[0020] Among them, ratio_R represents the initial adjustment ratio of the R channel, ratio_G represents the initial adjustment ratio of the G channel, ratio_B represents the initial adjustment ratio of the B channel, targetR represents the standard gain value of the R channel, and targetB represents the standard gain value of the B channel;

[0021] S8: normalizing the initial adjustment ratios of the three channels R, G, and B to obtain the final adjustment ratios of the three channels R, G, and B;

[0022] new_ratio_R=1-(1-ratio_R / max_ratio)*coff0

[0023] new_ratio_G=1-(1-1 / max_ratio)*coff0

[0024] new_ratio_B=1-(1-ratio_B / max_ratio)*coff0

[0025] Among them, max_ratio represents the maximum value among ratio_R, ratio_G and ratio_B; coff0 represents the chroma adjustment coefficient, so that the minimum value among new_ratio_R, new_ratio_G and new_ratio_B calculated is greater than the set adjustment ratio lower limit; new_ratio_R represents the final adjustment ratio of the R channel; new_ratio_G represents the final adjustment ratio of the G channel; new_ratio_B represents the final adjustment ratio of the B channel;

[0026] S9: Calculate the brightness adjustment value white_nits according to the brightness difference brightness and the values ​​of the parameters AE_Target, Cur_exposure and total_gain output by the camera module in the current projection device:

[0027] white_nits=Coff*brightness / AE_Target / Cur_exposure / total_gain / 8

[0028] Among them, Coff represents the brightness adjustment coefficient, which is used to reduce the brightness difference between different batches of optical machines; AE_Target represents the current exposure; Cur_exposure represents the automatic exposure target value; total_gain represents the total gain;

[0029] S10: The optical machine brightness is adjusted according to the brightness adjustment value, and the optical machine chromaticity is adjusted according to the final adjustment ratio of the three channels R, G, and B.

[0030] Furthermore, the characteristic image is an image used for gradient correction and / or confocalization of a projection device.

[0031] Furthermore, the correction area is an area in the feature image close to the center of the image.

[0032] Furthermore, the standard gain value of the R channel is the current gain value of the R channel under a standard environment; the standard gain value of the B channel is the current gain value of the B channel under a standard environment; the standard environment is a front projection on a white wall in a dark room at a distance of 2 meters.

[0033] Furthermore, the method for adjusting the optical machine brightness according to the brightness adjustment value is: pre-constructing a mapping table corresponding to the brightness adjustment value and the brightness serial number; when the brightness adjustment value is calculated, obtaining the corresponding brightness serial number through a table lookup method, and setting the corresponding optical machine brightness according to the brightness serial number.

[0034] A projection device comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method in an embodiment of the present invention when executing the computer program.

[0035] The present invention adopts the above technical solution to integrate color distortion correction and brightness correction into one correction image, and the correction image adopts the same feature image originally used for gradient correction or focusing, thereby improving the correction speed, increasing the correction accuracy, and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Shown is a flow chart of a method according to a first embodiment of the present invention. DETAILED DESCRIPTION

[0037] To further illustrate various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in this field should be able to understand other possible implementations and advantages of the present invention.

[0038] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0039] Embodiment 1:

[0040] The embodiment of the present invention provides a method for correcting the color distortion of a wall surface of a projection device, such as Figure 1 As shown, the method comprises the following steps:

[0041] S1: After the brightness ratios of the three channels R (red), G (green), and B (blue) of the projection device (projector) are set to 100% respectively, a feature image containing only black and white colors is projected through the projection device.

[0042] In order to reduce the frequent switching of characteristic images during user use, in this embodiment, the characteristic image used for gradient correction and / or focusing of the projection device itself is used as the characteristic image used for color distortion and brightness correction.

[0043] S2: Select an area from the feature image as the correction area.

[0044] In order to avoid interference from the external environment, in this embodiment, it is preferred to select an area close to the center of the image as the correction area, and the shape and size can be set by oneself and are not limited here.

[0045] S3: Obtain the average grayscale values ​​aveR, aveG, and aveB of the three channels R, G, and B corresponding to all white pixels in the correction area, and use the average grayscale value of the G channel as the average brightness brightness_w corresponding to white.

[0046] S4: Obtain the average grayscale value of the G channel corresponding to all black pixels in the correction area, and use it as the average brightness brightness_b corresponding to black.

[0047] S5: Calculate the brightness difference between white and black: brightness=brightness_w-brightness_b.

[0048] S6: Calculate the current gain value curGain_R of the R channel and the current gain value curGain_B of the B channel;

[0049] curGain_R=1024*aveG / aveR

[0050] curGain_B=1024*aveG / aveB

[0051] Among them, aveR represents the average grayscale value of the R channel; aveG represents the average grayscale value of the G channel; aveB represents the average grayscale value of the B channel.

[0052] S7: Calculate the initial adjustment ratio of the three channels R, G, and B:

[0053] ratio_R=curGain_R / targetR

[0054] ratio_G=1

[0055] ratio_B = curGain_B / targetB

[0056] Among them, ratio_R represents the initial adjustment ratio of the R channel, ratio_G represents the initial adjustment ratio of the G channel, ratio_B represents the initial adjustment ratio of the B channel, targetR represents the standard gain value of the R channel, and targetB represents the standard gain value of the B channel. The standard gain value of each projection device needs to be calibrated before use. In this embodiment, the standard gain value is obtained by simulating the standard environment when the user uses it. The standard environment is set to be a front projection on a white wall in a dark room at a distance of 2 meters. The standard gain value of the R channel is the current gain value of the R channel under the standard environment; the standard gain value of the B channel is the current gain value of the B channel under the standard environment.

[0057] S8: Normalize the initial adjustment ratios of the three channels R, G, and B to obtain the final adjustment ratios of the three channels R, G, and B:

[0058] new_ratio_R=1-(1-ratio_R / max_ratio)*coff0

[0059] new_ratio_G=1-(1-1 / max_ratio)*coff0

[0060] new_ratio_B=1-(1-ratio_B / max_ratio)*coff0

[0061] Among them, max_ratio represents the maximum value of ratio_R, ratio_G and ratio_B; coff0 represents the chromaticity adjustment coefficient, so that the minimum value of the calculated new_ratio_R, new_ratio_G and new_ratio_B is greater than the set lower limit of the adjustment ratio; the value of the lower limit of the adjustment ratio can be set by the technicians in this field according to the usage, and can be initially set to 0.5, and then can be appropriately increased, such as set to 0.8. The chromaticity adjustment coefficient coff0 can be adjusted according to the required lower limit of the adjustment ratio; new_ratio_R represents the final adjustment ratio of the R channel; new_ratio_G represents the final adjustment ratio of the G channel; new_ratio_B represents the final adjustment ratio of the B channel.

[0062] S9: Calculate the brightness adjustment value white_nits according to the brightness difference brightness and the values ​​of the parameters AE_Target, Cur_exposure and total_gain output by the camera module in the current projection device:

[0063] white_nits=Coff*brightness / AE_Target / Cur_exposure / total_gain / 8

[0064] Among them, Coff represents the brightness adjustment coefficient, which is used to reduce the brightness difference between light machines produced in different batches. When the light emitted by the light machine is brighter, the brightness adjustment coefficient is increased. When the light emitted by the light machine is darker, the brightness adjustment coefficient is reduced. In this embodiment, the value is 170 after batch experiments; AE_Target represents the current exposure; Cur_exposure represents the automatic exposure target value; total_gain represents the total gain.

[0065] S10: The optical machine brightness is adjusted according to the brightness adjustment value, and the optical machine chromaticity is adjusted according to the final adjustment ratio of the three channels R, G, and B.

[0066] In this embodiment, the method for adjusting the brightness of the optical machine according to the brightness adjustment value is: pre-constructing a mapping table corresponding to the brightness adjustment value and the brightness serial number; when the brightness adjustment value is calculated, the corresponding brightness serial number is obtained by looking up the table by the table lookup method, and the corresponding optical machine brightness is set according to the brightness serial number (each brightness serial number corresponds to a brightness value).

[0067] The method proposed in this embodiment can be configured in the projection device to be turned on by remote control.

[0068] Embodiment 2:

[0069] The present invention also provides a projection device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps in the above method embodiment of the first embodiment of the present invention when executing the computer program.

[0070] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A method for correcting color distortion and brightness of a wall of a projection device, characterized in that: The following steps are involved: S1: After setting the brightness ratios of the three channels R, G, and B of the projection device to 100% respectively, a feature image containing only black and white colors is projected through the projection device; S2: Select an area from the feature image as the correction area; S3: Get the average grayscale values ​​aveR, aveG, aveB of the three channels of R, G, and B corresponding to all white pixels in the correction area, and use the average grayscale value of the G channel as the average brightness brightness_w corresponding to white; S4: Obtain the average grayscale value of the G channel corresponding to all black pixels in the correction area, and use it as the average brightness brightness_b corresponding to black; S5: Calculate the brightness difference between white and black: brightness = brightness_w - brightness_b; S6: Calculate the current gain value curGain_R of the R channel and the current gain value curGain_B of the B channel; curGain_R=1024*aveG / aveR curGain_B=1024*aveG / aveB Wherein, aveR represents the average gray value of the R channel; aveG represents the average gray value of the G channel; aveB represents the average gray value of the B channel; S7: Calculate the initial adjustment ratio of the three channels R, G, and B: ratio_R=curGain_R / targetR ratio_G=1 ratio_B = curGain_B / targetB Among them, ratio_R represents the initial adjustment ratio of the R channel, ratio_G represents the initial adjustment ratio of the G channel, ratio_B represents the initial adjustment ratio of the B channel, targetR represents the standard gain value of the R channel, and targetB represents the standard gain value of the B channel; S8: normalizing the initial adjustment ratios of the three channels R, G, and B to obtain the final adjustment ratios of the three channels R, G, and B; new_ratio_R=1-(1-ratio_R / max_ratio)*coff0 new_ratio_G=1-(1-1 / max_ratio)*coff0 new_ratio_B=1-(1-ratio_B / max_ratio)*coff0 Among them, max_ratio represents the maximum value among ratio_R, ratio_G and ratio_B; coff0 represents the chroma adjustment coefficient, so that the minimum value among new_ratio_R, new_ratio_G and new_ratio_B calculated is greater than the set adjustment ratio lower limit; new_ratio_R represents the final adjustment ratio of the R channel; new_ratio_G represents the final adjustment ratio of the G channel; new_ratio_B represents the final adjustment ratio of the B channel; S9: Calculate the brightness adjustment value white_nits according to the brightness difference brightness and the values ​​of the parameters AE_Target, Cur_exposure and total_gain output by the camera module in the current projection device: white_nits=Coff*brightness / AE_Target / Cur_exposure / total_gain / 8 Among them, Coff represents the brightness adjustment coefficient, which is used to reduce the brightness difference between different batches of optical machines; AE_Target represents the current exposure; Cur_exposure represents the automatic exposure target value; total_gain represents the total gain; S10: The optical machine brightness is adjusted according to the brightness adjustment value, and the optical machine chromaticity is adjusted according to the final adjustment ratio of the three channels R, G, and B.

2. The method for correcting wall color distortion and brightness of a projection device according to claim 1, characterized in that: The characteristic image is an image used for gradient correction and / or confocalization of the projection device.

3. The method for correcting wall color distortion and brightness of a projection device according to claim 1, characterized in that: The correction area is the area in the feature image close to the center of the image.

4. The method for correcting wall color distortion and brightness of a projection device according to claim 1, characterized in that: The standard gain value of the R channel is the current gain value of the R channel under a standard environment; the standard gain value of the B channel is the current gain value of the B channel under a standard environment; the standard environment is a front projection on a white wall in a dark room at a distance of 2 meters.

5. The method for correcting wall color distortion and brightness of a projection device according to claim 1, characterized in that: The method for adjusting the optical machine brightness according to the brightness adjustment value is: pre-constructing a mapping table corresponding to the brightness adjustment value and the brightness serial number; when the brightness adjustment value is calculated, obtaining the corresponding brightness serial number through a table lookup method, and setting the corresponding optical machine brightness according to the brightness serial number.

6. A projection device, characterized in that: The method comprises a processor, a memory and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the methods of claims 1 to 5 when executing the computer program.

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