CN101674443B - Method for correcting colors of projector - Google Patents
Method for correcting colors of projector Download PDFInfo
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- CN101674443B CN101674443B CN2009100675044A CN200910067504A CN101674443B CN 101674443 B CN101674443 B CN 101674443B CN 2009100675044 A CN2009100675044 A CN 2009100675044A CN 200910067504 A CN200910067504 A CN 200910067504A CN 101674443 B CN101674443 B CN 101674443B
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Abstract
The invention provides a method for correcting colors of a projector, comprising the following steps: using a light meter to adjust parameters such as aperture, exposure time and the like of a camera; comparing the projected image obtained by the camera with an original image, using a nonlinear optimization method to fit a luminosity response curve; using the luminosity response curve to correct the original image to obtain a high-quality projected image suitable for human eyes. The method has advantages that a method of computer software is used, the problem of the color difference in a single-projection display system or a multi-projection display system is solved, the quality of pictures and the visual effect are improved, expensive and complicated special optical apparatuses are not needed, at the same time, the number of the photos needed in a HDR method is greatly reduced (the HDR method needs to shoot ten images, the method of the invention needs one image); and the method has simple operation, easy practicality and strong extensibility.
Description
Technical field
The present invention relates to a kind of conveniently method for correcting colors of projector, be widely used in fields such as the virtual reality relevant such as all kinds of projecting apparatus, Military Simulation, video conference, industrial design with Display Technique, solve the response of projecting apparatus self luminance non-linearity, output color with problems such as color distortions between variation service time, multi-projector, realization colors of projector low-cost, that easily implement, operate is well proofreaied and correct.
Background technology
Along with virtual reality technology develops rapidly, Visual Display more and more is subject to people's attention.Consciousness and psychological study show, people can feel easily that 2% luminance difference and the optical wavelength of 2nm change the color distortion that brings.Yet for projection display technique, along with the projecting apparatus increase of service time, the color of projecting apparatus meeting deepening (this useful life with the bulb of projecting apparatus inside is relevant); Luminance non-linearity response in the separate unit projecting apparatus; Simultaneously and since the manufacturer of projecting apparatus, kind, active time etc. different, also can have the difference on brightness and the color between the projecting apparatus.Even also can there be difference more or less in the projecting apparatus of the same kind of same manufacturers produce.Therefore, arise at the historic moment at the bearing calibration of color distortion in the display systems such as projecting apparatus.
Color calibration method is broadly divided into hardware optical device method and software engineering method two classes, and the former is based on professional optical devices such as photometer, spectroradiometers, and the latter is based on high dynamic range (HDR, high dynamicrange) image technique.The subject matter of color correction is luminosity response (ITF, the intensity transfer function) curve that how to obtain projecting apparatus.People such as Wallace use the color space of colored illuminance meter measuring projector, determine the color map of projecting apparatus to normed space by nonparametric model.People such as Majumder use spectroradiometer to come the color characteristics of measuring projector, and set up the three-channel color lookup table of RGB, thereby realize the mapping of color space.The weak point of these two kinds of methods is to depend on expensive professional optical device, complicated operation, cost height.People such as Raij A have used the HDR technology, and the output brightness the when rgb value of projecting apparatus is increased progressively is sampled, and obtain some HDR images, and then obtain the approximate ITF curve of projecting apparatus, and weak point is exactly to need a large amount of sampled images, are difficult in practice use.Color correction how to realize low cost, high efficiency, easy enforcement is most important.
Summary of the invention
To the objective of the invention is the color distortion problem that occurs in single-throw shadow or the many projection display systems in order solving, to improve the visual experience of display system, reduce technical costs, method simplifies the operation.
The invention provides a kind of method for correcting colors of projector, use light meter to adjust parameters such as the aperture of camera, time for exposure; Projected image and original image that camera is obtained compare, and utilize the nonlinear optimization method to simulate brightness response curve (being called for short the ITF curve); To original image, utilize the ITF curve to proofread and correct, obtain being suitable for the high-quality projected image of human eye vision.By using this invention, image quality and visual effect have been improved, reduced the color distortion of display system, avoided using expensive complicated optical device, (the HDR method need be taken tens of images to needed number of pictures when also having reduced employing HDR method significantly simultaneously, this method only needs one), simple to operate, easy to implement.
1. as shown in Figure 1, the present invention is made up of 6 parts: light meter (1), projection screen (2), camera (3), computer set (4), display system (5) and uncalibrated image (8); Wherein, computer set (4) is formed (N is a positive integer) by N computer (6); Display system (5) is made up of N projecting apparatus (7); Uncalibrated image (8) is stored in the computer (6).
2. performing step:
Step 1: the inventive method (100) part, obtain brightness response curve (being called for short the ITF curve), concrete steps are as follows:
Step 110: beginning;
Step 120: computer (6) reads uncalibrated image (8);
Step 121: computer (6) calculates the image coordinate (abscissa and ordinate) of each sampled point (sampling number depends on the color progression of uncalibrated image (8), and scope is 1 to 256) in the uncalibrated image (8);
Step 122: computer (6) extracts its color value to be thrown according to the image coordinate of each sampled point;
Step 130: computer (6) projects to projection screen (2) with uncalibrated image (8) by projecting apparatus (7) and goes up demonstration, obtains the Projection Display image;
Step 131: light meter (1) is preceding at projection screen (2), over against projecting apparatus (7), and light meter (1) measure ambient light; Time for exposure and aperture combination that light meter (1) is read are set in the camera (3);
Step 132: use the Projection Display image on camera (3) the shooting projection screen (2), acquisition and uncalibrated image (8) have the projected image of color distortion, abbreviate projected image as;
Step 133: computer (6) calculates each sampled point corresponding coordinate in projected image;
Step 134: computer (6) extracts its color value in projected image according to each sampled point corresponding coordinate in projected image, and this color value abbreviates the projection color value as;
Step 140: the waiting of each sampled point thrown color value and projection color value, and to form color value right, utilizes these color values right, simulates ITF curve (this curve is the corresponding relation of waiting to throw between color value and the projection color value);
Step 150: find the solution the inverse function curve of ITF curve, set up color lookup table (this color lookup table is the projection color value and waits to throw corresponding relation between the color value).
Step 2: the inventive method (200) part, the original image in the computer (6) is carried out real-time color proofread and correct, the image to be thrown after obtaining proofreading and correct is projected in projection screen (2) by projecting apparatus (7) and goes up correct demonstration, and concrete steps are as follows:
Step 210: on computer (6), input need be projected in original image on the projection screen (2) through projecting apparatus (7);
Step 220: computer (6) reads the color value of every bit in the original image, i.e. projection color value;
Step 230: utilize the color lookup table of the ITF curve that this method (100) part tries to achieve, obtain the color value to be thrown of projection color value correspondence;
Step 240: the color value to be thrown of record original image every bit, obtain image to be thrown, will wait to throw image projection to projection screen (2) by projecting apparatus (7), show the projected image after proofreading and correct.
Above-mentioned performing step can be realized between computer set (4) and display system (5).
Beneficial effect
The purpose of this invention is to provide a kind of conveniently method for correcting colors of projector.Its advantage be to use a computer method of software, solved the color distortion problem that occurs in single-throw shadow or the many projection display systems, image quality and visual effect have been improved, expensive and complicated professional optical device have been avoided using, needed number of pictures (the HDR method need be taken tens of images, and this method only needs one) when also having reduced employing HDR method significantly simultaneously, simple to operate, easy to implement, and expandability is strong.
Description of drawings
Fig. 1 is a colors of projector corrective system pie graph.This figure also is the specification digest accompanying drawing.Wherein: 1 is light meter, and 2 is projection screen, and 3 is camera, and 4 is computer set, and 5 is display system, and 6 is computer, and 7 is projecting apparatus, and 8 is uncalibrated image.
Fig. 2 is a uncalibrated image.
Fig. 3 is the flow chart of the inventive method.
Fig. 4 is the color correction effect contrast figure.Wherein: first width of cloth is for treating projected image, and second width of cloth is uncorrected projection result image, and the 3rd width of cloth is the projection result image after proofreading and correct.
Embodiment
Step 1: the inventive method (100) part, obtain the ITF curve, concrete steps are as follows:
Step 110: beginning;
Step 120: computer (6) reads uncalibrated image (8);
Step 121: computer (6) calculates the image coordinate (abscissa and ordinate) of each sampled point (sampling number depends on the color progression of uncalibrated image (8), and scope is 1 to 256) in the uncalibrated image (8);
Step 122: computer (6) extracts its color value to be thrown according to the image coordinate of each sampled point;
Step 130: computer (6) projects to projection screen (2) with uncalibrated image (8) by projecting apparatus (7) and goes up demonstration, obtains the Projection Display image;
Step 131: light meter (1) is preceding at projection screen (2), over against projecting apparatus (7), and light meter (1) measure ambient light; Time for exposure and aperture combination that light meter (1) is read are set in the camera (3);
Step 132: use the Projection Display image on camera (3) the shooting projection screen (2), acquisition and uncalibrated image (8) have the projected image of color distortion, abbreviate projected image as;
Step 133: computer (6) calculates each sampled point corresponding coordinate in projected image;
Step 134: computer (6) extracts its color value in projected image according to each sampled point corresponding coordinate in projected image, and this color value abbreviates the projection color value as;
Step 140: the waiting of each sampled point thrown color value and projection color value, and to form color value right, utilizes these color values right, simulates the ITF curve;
Step 150: find the solution the inverse function curve of ITF curve, set up color lookup table.
Step 2: the inventive method (200) part, the original image in the computer (6) is carried out real-time color proofread and correct, the image to be thrown after obtaining proofreading and correct is projected in projection screen (2) by projecting apparatus (7) and goes up correct demonstration, and concrete steps are as follows:
Step 210: on computer (6), input need be projected in original image on the projection screen (2) through projecting apparatus (7);
Step 220: computer (6) reads the color value of every bit in the original image, i.e. projection color value;
Step 230: utilize the color lookup table of the ITF curve that this method (100) part tries to achieve, obtain the color value to be thrown of projection color value correspondence;
Step 240: the color value to be thrown of record original image every bit, obtain image to be thrown, will wait to throw image projection to projection screen (2) by projecting apparatus (7), show the projected image after proofreading and correct.
Claims (1)
1. a method for correcting colors of projector is characterized in that, its equipment needed thereby and performing step are as follows:
Equipment needed thereby: light meter (1), projection screen (2), camera (3), computer set (4), display system (5) and uncalibrated image (8); Wherein, computer set (4) is made up of N computer (6), and described N is a positive integer; Display system (5) is made up of N projecting apparatus (7); Uncalibrated image (8) is stored in the computer (6);
Performing step:
Step 1: obtain brightness response curve, concrete steps are as follows:
Step 110: beginning;
Step 120: computer (6) reads uncalibrated image (8);
Step 121: computer (6) calculates the image coordinate of each sampled point in the uncalibrated image (8), comprises abscissa and ordinate, and the number of sampled point depends on the color progression of uncalibrated image (8), and scope is 1 to 256;
Step 122: computer (6) extracts its color value to be thrown according to the image coordinate of each sampled point;
Step 130: computer (6) projects to projection screen (2) with uncalibrated image (8) by projecting apparatus (7) and goes up demonstration, obtains the Projection Display image;
Step 131: light meter (1) is preceding at projection screen (2), over against projecting apparatus (7), and light meter (1) measure ambient light; Time for exposure and aperture combination that light meter (1) is read are set in the camera (3);
Step 132: use the Projection Display image on camera (3) the shooting projection screen (2), acquisition and uncalibrated image (8) have the projected image of color distortion;
Step 133: computer (6) calculates each sampled point corresponding coordinate in projected image;
Step 134: computer (6) extracts its color value in projected image according to each sampled point corresponding coordinate in projected image, and this color value abbreviates the projection color value as;
Step 140: the waiting of each sampled point thrown color value and projection color value, and to form color value right, utilizes these color values right, simulates brightness response curve, and this brightness response curve is the corresponding relation of waiting to throw between color value and the projection color value;
Step 150: find the solution the inverse function curve of brightness response curve, set up color lookup table, this color lookup table is the projection color value and waits to throw corresponding relation between the color value;
Step 2: the original image in the computer (6) is carried out real-time color proofread and correct, the image to be thrown after obtaining proofreading and correct is projected in projection screen (2) by projecting apparatus (7) and goes up correct demonstration, and concrete steps are as follows:
Step 210: on computer (6), input need be projected in original image on the projection screen (2) through projecting apparatus (7);
Step 220: computer (6) reads the color value of every bit in the original image, i.e. projection color value;
Step 230: utilize color lookup table, obtain the color value to be thrown of projection color value correspondence;
Step 240: the color value to be thrown of record original image every bit, obtain image to be thrown, will wait to throw image projection to projection screen (2) by projecting apparatus (7), show the projected image after proofreading and correct.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN2009100675044A CN101674443B (en) | 2009-09-08 | 2009-09-08 | Method for correcting colors of projector |
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| CN2009100675044A CN101674443B (en) | 2009-09-08 | 2009-09-08 | Method for correcting colors of projector |
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| CN101674443A CN101674443A (en) | 2010-03-17 |
| CN101674443B true CN101674443B (en) | 2011-09-21 |
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Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102202199A (en) * | 2010-03-24 | 2011-09-28 | 鸿富锦精密工业（深圳）有限公司 | Projector and image regulating method thereof |
| CN101968956B (en) * | 2010-10-15 | 2012-10-03 | 广东威创视讯科技股份有限公司 | Color calibration method of display units |
| CN102469239B (en) * | 2010-11-17 | 2015-06-17 | 北大方正集团有限公司 | Color correction method and device |
| CN102540681A (en) * | 2010-12-15 | 2012-07-04 | 鸿富锦精密工业（深圳）有限公司 | Projector and automatic projected picture adjustment method thereof |
| CN102156877A (en) * | 2011-04-01 | 2011-08-17 | 长春理工大学 | Cluster-analysis-based color classification method |
| CN102801952B (en) * | 2011-05-28 | 2015-01-21 | 华为终端有限公司 | Method and device for adjusting video conference system |
| CN102244757B (en) * | 2011-06-07 | 2013-09-18 | 北京邮电大学 | Color calibration method of large multi-projection screen based on projector-camera system |
| CN103179322B (en) * | 2011-12-20 | 2016-03-02 | 联想(北京)有限公司 | A kind of image color correction method and electronic equipment |
| CN103634544B (en) * | 2012-08-20 | 2019-03-29 | 联想(北京)有限公司 | A kind of projecting method and electronic equipment |
| CN103200409B (en) * | 2013-04-10 | 2015-06-03 | 苏州展科光电科技有限公司 | Color correction method of multi-projector display system |
| CN105430308B (en) * | 2014-09-17 | 2020-04-03 | 索尼公司 | Interactive projection device and automatic exposure value adjusting method thereof |
| CN105677005B (en) * | 2014-11-19 | 2020-12-11 | 中兴通讯股份有限公司 | Screen control method and device of mobile terminal |
| CN105072365B (en) * | 2015-07-29 | 2018-04-13 | 深圳华侨城文化旅游科技股份有限公司 | A kind of method and system of the lower enhancing image effect of metal curtain projection |
| CN105072428B (en) * | 2015-07-29 | 2017-04-12 | 深圳华侨城文化旅游科技股份有限公司 | Automatic color correction method of projector |
| CN106559627B (en) * | 2015-09-25 | 2021-05-11 | 中兴通讯股份有限公司 | Projection method, device and equipment |
| CN108337493A (en) * | 2018-01-16 | 2018-07-27 | 长春华懋科技有限公司 | Automatic correction method of image color based on high-precision vision holder |
| CN110868575B (en) * | 2018-08-27 | 2022-09-06 | 深圳光峰科技股份有限公司 | Color adjustment device and color fusion system for projection image |
| CN109685853B (en) * | 2018-11-30 | 2021-02-02 | Oppo广东移动通信有限公司 | Image processing method, image processing device, electronic equipment and computer readable storage medium |
| CN111416968B (en) * | 2019-01-08 | 2022-01-11 | 精工爱普生株式会社 | Projector, display system, and image correction method |
| CN110708526A (en) * | 2019-10-15 | 2020-01-17 | 歌尔股份有限公司 | Illuminance measuring method, measuring device, computer equipment and storage medium |
| CN111722820A (en) * | 2020-05-13 | 2020-09-29 | 青岛欧亚丰科技发展有限公司 | Large screen control system |
| CN113052920B (en) * | 2021-04-26 | 2022-11-22 | 歌尔光学科技有限公司 | Camera calibration method, device and computer readable storage medium |
| CN115277966B (en) * | 2021-04-30 | 2023-12-08 | 苏州佳世达光电有限公司 | 3D scanning correction system and 3D scanning correction method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101236066A (en) * | 2008-03-04 | 2008-08-06 | 东南大学 | Projection grating self-correction method |
| CN101321303A (en) * | 2008-07-17 | 2008-12-10 | 上海交通大学 | Geometric and optical correction method for non-plane multi-projection display |
| CN101336546A (en) * | 2006-02-07 | 2008-12-31 | 夏普株式会社 | Image projecting method and projector |
-
2009
- 2009-09-08 CN CN2009100675044A patent/CN101674443B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101336546A (en) * | 2006-02-07 | 2008-12-31 | 夏普株式会社 | Image projecting method and projector |
| CN101236066A (en) * | 2008-03-04 | 2008-08-06 | 东南大学 | Projection grating self-correction method |
| CN101321303A (en) * | 2008-07-17 | 2008-12-10 | 上海交通大学 | Geometric and optical correction method for non-plane multi-projection display |
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