Projection system and method for uniformity correction

Abstract

A projection system and calibration method involve: a light source configured to emit light in response to image data; an optical system configured to project the light emitted by the light source; receiving input associated with a plurality of light values ​​corresponding to a plurality of primary color light fields; converting the input associated with the plurality of light values ​​into a plurality of projector primary color values; determining a gain map based on the plurality of projector primary color values; applying the gain map to an image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that the primary color mix is ​​the same across an image frame; and projecting the image with the image frame using the optical system, wherein a second image is corrected by the gain map.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application Nos. 61 / 967,655 and 63 / 125,202, filed on January 30, 2020 and December 14, 2020, respectively, each of which is incorporated by reference in its entirety. background 1. Technical Field

[0004] The present application relates generally to projection systems and methods for correcting uniformity errors in image frames.

[0005] 2. Related technologies

[0006] Digital projection systems typically utilize a light source and an optical system to project an image onto a surface or screen. The light source, which acts as a color display, mixes primary colors to produce other colors. In order to display or project a specific color, precise mixing is necessary and must be repeated across the entire image frame. For example, when displaying a pure white image, the light source maximizes the red, green, and blue values ​​at every point on the surface or screen. However, when the precise mixing across the image frame is not the same, uniformity errors occur in the image. Uniformity errors may be caused by the physical characteristics of the digital projection system (e.g., manufacturing tolerances, wear of projector components, thermal effects, bent cables, etc.). Image uniformity errors can be classified into chromaticity uniformity errors and brightness uniformity errors. For example, tinting may occur along the edges of the projected image (chromaticity uniformity error), or some parts of the projected image may appear brighter than other parts (brightness uniformity error). Summary of the invention

[0007] Various aspects of the present disclosure are directed to apparatus, systems, and methods for performing uniformity correction of a displayed image.

[0008] In an exemplary aspect of the present disclosure, a projection system is provided, comprising: a light source configured to emit light in response to image data; an optical system configured to project the light emitted by the light source; and a controller configured to: receive input associated with a plurality of light values ​​corresponding to a plurality of primary color light fields, convert the input associated with the plurality of light values ​​into a plurality of projector primary color values, determine a gain map based on the plurality of projector primary color values, apply the gain map to an image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that the primary color mixing is the same on an image frame, and project an image with the image frame using the optical system, wherein a second image is corrected by the gain map.

[0009] In another exemplary aspect of the present disclosure, a method for correcting an image provided by a light source configured to emit light in response to image data, and an optical system configured to project light emitted by the light source is provided, the method comprising: receiving an input associated with a plurality of light values ​​corresponding to a plurality of primary color light fields; converting the input associated with the plurality of light values ​​into a plurality of projector primary color values; determining a gain map based on the plurality of projector primary color values; applying the gain map to the image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that the primary color mixing is the same on an image frame; and projecting the image with the image frame using the optical system, wherein a second image is corrected by the gain map.

[0010] In another exemplary aspect of the present disclosure, a non-transitory computer-readable medium storing instructions is provided, which, when executed by a processor of a projection system including a light source configured to emit light in response to image data and an optical system configured to project the light emitted by the light source, causes the projection device to perform operations including the following: receiving an input associated with a plurality of light values ​​corresponding to a plurality of primary color light fields; converting the input associated with the plurality of light values ​​into a plurality of projector primary color values; determining a gain map based on the plurality of projector primary color values; applying the gain map to an image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that the primary color mix is ​​the same across an image frame; and projecting an image with the image frame using the optical system, wherein a second image is corrected by the gain map.

[0011] In this way, various aspects of the present disclosure provide for the display of images with high dynamic range and high resolution, and provide effective improvements in at least the technical fields of image projection, holography, signal processing, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] These and other more detailed and specific features of various embodiments are more fully disclosed in the following description with reference to the accompanying drawings, in which:

[0013] Figure 1 illustrates a block diagram of an exemplary projection system according to various aspects of the present disclosure;

[0014] FIG. 2A to FIG. 2B illustrates a view of an exemplary spatial light modulator for use with various aspects of the present disclosure;

[0015] Figure 3 Picture shows Figure 1 An exemplary calibration method in an exemplary optical system;

[0016] FIG. 4A to FIG. 4C The diagram shows Figure 1 a view of an uncorrected light field projected by an exemplary optical system of FIG.

[0017] FIG. 5A to FIG. 5C The diagram shows the application FIG. 4A to FIG. 4C a chroma-corrected view of the uncorrected light field; and

[0018] Figure 6 The diagram shows FIG. 5A to FIG. 5C View of the brightness distribution after chroma correction. DETAILED DESCRIPTION

[0019] The present disclosure and various aspects may be implemented in various forms, including: hardware, devices or circuits controlled by computer-implemented methods, computer program products, computer systems and networks, user interfaces and application programming interfaces; as well as hardware-implemented methods, signal processing circuits, memory arrays, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), etc. The foregoing summary is intended only to give a general idea of ​​the various aspects of the present disclosure and is not intended to limit the scope of the present disclosure in any way.

[0020] In the following description, many details such as optical device configuration, timing, operation, etc. are set forth to provide an understanding of one or more aspects of the present disclosure. It is obvious to those skilled in the art that these specific details are only exemplary and are not intended to limit the scope of the present application.

[0021] In addition, although the present disclosure focuses primarily on examples of using various circuits in digital projection systems, it should be understood that this is only one example of an implementation. It should be further understood that the disclosed systems and methods can be used in any device that requires projection of light; for example, theater projection systems, consumer-grade projection systems and other commercial projection systems, head-up displays, virtual reality displays, etc. The disclosed systems and methods can be implemented in additional display devices, such as using OLED displays, LCD displays, quantum dot displays, etc.

[0022] Chromaticity uniformity and brightness uniformity

[0023] As mentioned previously, image uniformity can be categorized into chromaticity uniformity and brightness uniformity. Chromaticity uniformity is a measure of the variation in chromaticity across an image frame (i.e., the entire frame of pixels that create the image) without regard to the absolute chromaticity of the desired color. Chromaticity uniformity can be measured by comparing the chromaticity of the image to the chromaticity of the desired color.

[0024] Brightness uniformity is a measure of how well the brightness across an image frame conforms to a specified brightness distribution. Although the brightness distribution may not be flat, uniform brightness can be smooth and symmetrical about the center of the image - although the center will be brighter. Brightness uniformity may not consider the absolute brightness of the desired color, but rather the brightness distribution. Brightness uniformity can be measured by comparing the brightness of the image to the brightness of the desired color. If the brightness distribution is not flat, the brightness should be matched in the center of the image.

[0025] The eye of a viewer of a projected image may not perceive variations in brightness uniformity and chromaticity uniformity equally. Brightness uniformity errors can be quite large without being noticeably objectionable and can be ignored in some cases. However, chromaticity uniformity errors are easily noticed. For example, for a white flat-field image, if the chromaticity is uniform and the brightness deviates smoothly from the brightness distribution by between 10% and 20%, the probability of an observer noticing a brightness error is low. However, if each primary color differs from each other by between 10% and 20% in terms of chromaticity, chromaticity errors will be more easily noticed.

[0026] These deviations in chromaticity and brightness on the image frame occur due to the physical components of the projector having non-ideal behavior, which may be caused by manufacturing tolerances, wear of projector components, thermal effects, bent cables, etc. For example, when a flat white image is applied as input without uniformity correction, the screen shows the original primary color light field. In order to display the flat white image, the primary color light field may be fully driven at maximum power. Therefore, uniformity correction of the white image involves attenuating the light in certain areas of the primary color light field. Since high peak levels of the primary color light field are desirable, uniformity correction should minimize any reduction in brightness.

[0027] Chromatic uniformity correction adjusts the levels of the primary light fields themselves so that the primary color mix of the primary light fields is the same across the entire image frame. For example, if the primary light fields are red, green, and blue (i.e., RGB primaries), white is displayed when (R,G,B)=(1,1,1), where 1 is the maximum value of each light field. The primary light fields should be adjusted so that each point on the image frame is reduced to the minimum of these three primary light fields, thereby achieving chromatic uniformity with minimal total light loss. Performing this operation on a white screen can correct uniformity errors in all flat-field images of the projection system except white images. However, in cases where the levels of the primary light fields are so low that chromaticity correction results in unacceptably low light output, the display may be considered defective.

[0028] If chromaticity uniformity correction has been applied, brightness uniformity correction will adjust all primary light fields by the same amount, because each primary light field has the same level map or shape. However, this shape may not match the specified brightness distribution, and trying to match the specified brightness distribution involves reducing the light level of each primary light field. Therefore, brightness uniformity is only applied when non-uniformity is visible to the observer or the display must meet standard specifications for uniformity.

[0029] Chromaticity correction is affected by the target brightness distribution that all primary color light fields conform to. If any of the original primary color light fields is not smooth, the target brightness distribution, which is the minimum of the three light fields, may also be non-smooth. Chromaticity uniformity correction targeting a non-smooth brightness distribution will produce brightness non-uniformities that may be visible. To prevent this, a smooth lower limit of the minimum of the primary color light fields is used as the target brightness distribution. If brightness uniformity correction is included in the target brightness distribution, the same smoothness constraint can be used. The various correction operations described herein can be implemented by a projector, which will be described in more detail below.

[0030] Projector System

[0031] Figure 1 An exemplary high contrast projection system 100 according to various aspects of the present disclosure is illustrated. In particular, Figure 1 A projection system 100 is illustrated, which includes: a light source 101, which is configured to emit a first light 102; an illumination optical device 103 (an example of an illumination optical system according to the present disclosure), which is configured to receive the first light 102 and redirect, turn or otherwise modify the first light to generate a second light 104 (i.e., the turned light); a DMD 105, which is configured to receive the second light 104 and selectively redirect and / or modulate the second light into a third light 106 (i.e., the modulated light); a first projection optical device 107, which is configured to receive the third light 106 and project the third light into a fourth light 108; a filter 109, which is configured to filter the fourth light 108 to generate a fifth light 110; and a second projection optical device 111, which is configured to receive the fifth light 110 and project the fifth light as a sixth light 112 onto a screen 113.

[0032] In actual implementations, the projection system 100 may include fewer optical components or may include additional optical components, such as reflectors, lenses, waveguides, optical fibers, beam splitters, diffusers, etc. In addition to the screen 113, in one implementation, Figure 1The illustrated components can be integrated into a housing to provide a projection device. In other embodiments, the projection system 100 may include multiple housings. For example, the light source 101, the illumination optical device 103, and the DMD 105 may be disposed in a first housing, and the first projection optical device 107, the filter 109, and the second projection optical device 111 may be disposed in a second housing that can be matched with the first housing. In some further embodiments, one or more of these housings may themselves include subassemblies. One or more housings of such a projection device may include additional components such as a memory, an input / output port, a communication circuit, a power supply, and the like.

[0033] The light source 101 may be, for example, a laser light source, an LED, etc. In general, the light source 101 is any light emitter that emits light. In some embodiments, the light is coherent light. In some aspects of the present disclosure, the light source 101 may include a plurality of separate light emitters, each corresponding to a different wavelength or wavelength band. The light source 101 emits light in response to an image signal provided by a controller 114; the controller may be, for example, one or more processors of the projection system 100, such as a central processing unit (CPU). The image signal includes image data corresponding to a plurality of frames to be displayed continuously. The various elements in the projection system 100 (including the DMD 105) may be controlled by the controller 114. Although in Figure 1 Although not specifically shown in the figure, the controller 114 may additionally or alternatively control the illumination optical device 103, the first projection optical device 107, and the second projection optical device 111. The image signal may originate from an external source in a streaming or cloud-based manner, may originate from an internal memory of the projection system 100 such as a hard disk, may originate from a removable medium that is operably connected to the projection system 100, or from a combination of the above.

[0034] Although Figure 1 A generally linear optical path is illustrated, but in reality the optical path is often more complex.For example, in projection system 100, second light 104 from illumination optics 103 is turned at an oblique angle to DMD chip 105 (or chips).

[0035] To illustrate the impact of the incident angle and the DMD mirror, FIG. 2A to FIG. 2B An exemplary DMD 200 is shown in accordance with various aspects of the present disclosure. In particular, Figure 2A A plan view of the DMD 200 is shown, and Figure 2B The diagram shows Figure 2A2-B. The DMD 200 includes a plurality of square micromirrors 202 arranged in a two-dimensional rectangular array on a substrate 204. In some examples, the DMD 200 may be a digital light processor (DLP) from Texas Instruments. Each micromirror 202 may correspond to a pixel of a final projected image and may be configured to tilt around a rotation axis 208 (which is shown for a specific subset of micromirrors 202) due to electrostatic or other actuation. Each micromirror 202 has a width 212 and is arranged to be spaced apart by a gap having a width 210. The micromirrors 202 may be formed of or coated with any highly reflective material such as aluminum or silver, thereby specularly reflecting light. The gaps between the micromirrors 202 may be absorptive, so that the input light entering the gaps is absorbed by the substrate 204.

[0036] Although Figure 2A Only some representative micromirrors 202 are explicitly shown, but in practice the DMD 200 may include a greater number of individual micromirrors equal to the resolution of the projection system 100. In some examples, the resolution may be 2K (2048×1080), 4K (4096×2160), 1080p (1920×1080), consumer 4K (3840×2160), etc. Furthermore, in some examples, the micromirrors 202 may be rectangular and arranged in a rectangular array; may be hexagonal and arranged in a hexagonal array, etc. Furthermore, although Figure 2A The rotation axis 208 is illustrated extending in an oblique direction, but in some embodiments, the rotation axis 208 may extend vertically or horizontally.

[0037] like Figure 2B As can be seen in FIG. 1 , each micromirror 202 may be connected to a substrate 204 via a yoke 214 that is rotatably connected to the micromirror 202. The substrate 204 includes a plurality of electrodes 216. Figure 2B Only two electrodes 216 are visible per micromirror 202 in the cross-sectional view of FIG. 1 , but each micromirror 202 may actually include additional electrodes. Figure 2B As specifically shown in FIG. 2 , DMD 200 may further include a spacer layer, a support layer, a hinge component for controlling the height or orientation of micromirror 202, etc. Substrate 204 may include electronic circuits associated with DMD 200, such as CMOS transistors, memory elements, etc.

[0038] Depending on the specific operation and control of the electrode 216, each micromirror 202 can be switched between an "on" position, an "off" position, and an unactuated or neutral position. If the micromirror 202 is in the on position, it is actuated to an angle of, for example, -12° (i.e., 12° counterclockwise relative to the neutral position) to mirror-reflect the input light 206 into an on-state light 218. If the micromirror 202 is in the off position, it is actuated to an angle of, for example, +12° (i.e., 12° clockwise relative to the neutral position) to mirror-reflect the input light 206 into an off-state light 220. The off-state light 220 can be directed toward a light collector that absorbs the off-state light 220. In some examples, the micromirror 202 can be unactuated and parallel to the substrate 204. FIG. 2A to FIG. 2B The specific angles illustrated in and described herein are merely exemplary and non-limiting. In some embodiments, the open position angle and the closed position angle may be between ±11 degrees and ±13 degrees, respectively (including the endpoints).

[0039] exist Figure 1 In the context of FIG. 1 , i.e., in the case where the DMD mirror is tilted at an angle of 12° to reflect or discard light, the second light 104 is diverted to the DMD chip 105 at a fixed angle of 24°. When the individual mirrors are tilted at a first predetermined angle (e.g., −12°), the mirrors are considered to be in an on state and redirect light to the first projection optics 107, the filter 109, and the second projection optics 111 (e.g., a predetermined position). When the individual mirrors are tilted at a second predetermined angle (e.g., ±12°), the mirrors are considered to be in an off state and redirect light to a light collector located outside the active image area.

[0040] To ensure that the image on screen 113 has acceptable clarity and is chromatically and uniformly corrected across the image frame, controller 114 may be calibrated and / or configured to provide uniformity correction to the image data provided to light source 101 .

[0041] Uniformity Correction Method

[0042] Figure 3 An exemplary uniformity correction method is shown in FIG. Figure 1 The calibration of the projection system 100 is shown performed during . Figure 3 The correction method can be performed in an automated manner, for example by a computer program, as will be described in more detail below.

[0043] At operation 301, a correction method receives an input associated with a plurality of light values. The plurality of light values ​​may correspond to or be associated with a plurality of primary color light fields. For example, the plurality of light values ​​may include a value of a red light field at each point (e.g., each pixel) of an image frame, a value of a green light field at each point of the image frame, and a value of a blue light field at each point of the image frame.

[0044] In some embodiments, the input associated with the plurality of light values ​​of the first image is a photograph of the first image taken by a camera. For example, the first image is projected in an image frame using an optical system. The first image may be a white image composed of a plurality of primary color light fields, such as a red light field, a green light field, and a blue light field. The first image may include chromaticity errors, such as a decrease in chromaticity along an edge of the image frame. FIG. 4A to FIG. 4C An example light field of a first image is provided. Figure 4A The uncorrected red light field of the white image is provided, Figure 4B An uncorrected green light field of a white image is provided, and Figure 4C An uncorrected blue light field is provided for a white image.

[0045] As from Figure 4A As can be seen in Figure 1, the contour of the uncorrected red light field at a corner denoted as (0, 40) is lower than Figure 4B The uncorrected green light field and Figure 4C , which is the corresponding contour angle of the uncorrected blue light field in . This means that the brightness value of the red uncorrected light field at (0, 40) is lower than the brightness values ​​of the green uncorrected light field and the blue uncorrected light field at (0, 40). Similarly, the contour of the uncorrected red light field at (40, 40) is higher than the corresponding contours of the uncorrected green light field and the uncorrected blue light field. This means that the brightness value of the red uncorrected light field at (40, 40) is greater than the brightness value of the green uncorrected light field and the blue uncorrected light field at (40, 40).

[0046] The camera acts as a colorimeter that measures the R, G, and B values ​​of the first image projected by the projection system 100, because the camera image (e.g., the input associated with the plurality of light values) provides the R, G, and B values ​​measured at each point in the image frame. However, these values ​​may have undergone a linear transformation from the true values ​​projected by the projection system 100. At operation 302, the correction method converts the input into a plurality of projector primary color values. The conversion provides actual light values ​​of a plurality of light fields projected by the projector 100 and included in the first image.

[0047] At operation 303, the correction method determines a gain map based on the multiple projector primary color values. For example, when the first image projected by the projection system 100 is a white image, the R value, the G value, and the B value are each set to a maximum value. However, due to defects in manufacturing and / or calibration or non-ideal performance of physical components, the maximum value of each value may be slightly different. These may cause chromaticity reduction or other chromaticity errors and brightness errors in the first image. The projector primary color values ​​provide the actual values ​​output by the projection system 100 for the first image - including errors.

[0048] If each of the multiple primary color light fields is at a maximum value, uniformity can be achieved by reducing each R value, G value, and B value to the minimum value of the primary color light field. Therefore, the level of the red primary color light field, the level of the green primary color light field, and the level of the blue primary color light field are adjusted separately so that for each point in the image frame, the corresponding level is reduced to the minimum value of the level of each point. The gain map provides a diagram showing how much adjustment should be made at each point in the image frame to achieve uniformity. For example, Figure 5A Provides Figure 4A Red chromaticity correction of an uncorrected red light field. Figure 5B Provides Figure 4B Green chromaticity correction of an uncorrected green light field. Figure 5C Provides Figure 4C Blue chromaticity correction of an uncorrected blue light field.

[0049] like Figure 5B As shown, the level (e.g., light value) of the green light field at (0, 40) is multiplied by 0.9 to reduce the level. This reduction brings the level of the green light field down to the level of the red light field at (0, 40). Figure 5C In , a similar reduction is applied to the blue light field so that the level of the blue light field drops to the level of the red light field at (0, 40). Figure 5A As shown, the level of the red light field at (40, 40) is multiplied by 0.94 to reduce the level of the red light field to the level of the green light field at (40, 40).

[0050] At operation 304, the correction method applies the gain map to the image to perform chromaticity uniformity correction. Figure 5A , Figure 5B and Figure 5C The gain graph is applied to Figure 4A , Figure 4B and Figure 4CThe gain map may be applied to the image data by the controller 200 before the image data is provided to the light source 101. For example, the controller 200 modifies the image data provided to the light source 101 and, therefore, modifies the image projected by the light source 101. The image may be a second image different from the first image. At operation 305, the correction method projects an image in an image frame using an optical system. For example, an image defined by the corrected image data is displayed to a viewer. The second image may have a corrected light field, such as Figure 6 As shown. The second image can be visually uniform across the image frame. In addition, due to applying the gain map and adjusting the levels of the multiple primary color light fields, the second image can have a brightness distribution that is a smooth maximum lower limit of the multiple primary color light fields. By using the smooth maximum lower limit, a smooth brightness distribution is achieved.

[0051] As Figure 3 A specific example of the operation of , presented in pseudocode using a MATLAB-like format:

[0052]

[0053] In the above pseudo code, imgIn is the input image expressed in display primary color levels and may exhibit uniformity errors; imgGain is a gain image used to apply uniformity correction; imgShow is an image used to drive the display device; imgCapture is the displayed image captured by the camera and converted to display primary color levels; imgTarget is the level image to which the R image, G image, and B image will conform after correction; TakeAndConvertPicture() is a function that takes a photo of the display image and converts it to display primary color levels; minRGB() is a function that takes an RGB image and returns a monochrome image where R, G, and B are minimum values ​​for each pixel at that pixel; and Smooth() is a function that smoothes the image enough to remove unwanted higher spatial variations in brightness.

[0054] The operations described herein may be implemented as instructions or code stored on a non-transitory computer-readable medium, such as a hard disk or other storage medium included in or associated with the projection system 100 (eg, the memory of the controller 114).

[0055] The above-mentioned projection system and method can provide correction for uniformity errors in image frames.The systems, methods and devices according to the present disclosure can adopt any one or more of the following configurations.

[0056] (1) A projection system comprising: a light source configured to emit light in response to image data; an optical system configured to project the light emitted by the light source; and a controller configured to: receive input associated with a plurality of light values ​​corresponding to a plurality of primary color light fields, convert the input associated with the plurality of light values ​​into a plurality of projector primary color values, determine a gain map based on the plurality of projector primary color values, apply the gain map to an image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that the primary color mix is ​​the same over an image frame, and project an image with the image frame using the optical system, wherein a second image is corrected by the gain map.

[0057] (2) A projection system according to (1), wherein the optical system comprises: an illumination optical device configured to deflect light emitted by the light source to obtain deflected light; a digital micromirror device configured to receive the deflected light from the illumination optical device and convert the deflected light into modulated light; and a projection optical device configured to project the modulated light onto a screen.

[0058] (3) The projection system according to any one of (1) to (2), wherein the controller is further configured to project a first image in an image frame using the optical system, the first image including the plurality of primary color light fields.

[0059] (4) The projection system of any one of (1) to (3), wherein the input associated with the plurality of light values ​​of the first image is a photograph of the first image taken by a camera.

[0060] (5) The projection system according to any one of (1) to (4), wherein:

[0061] Applying the gain map to the image includes modifying an image signal provided by the light source.

[0062] (6) The projection system according to any one of (1) to (5), wherein the plurality of primary color light fields include a red primary color light field, a green primary color light field, and a blue primary color light field.

[0063] (7) A projection system according to (6), wherein the levels of the red primary light field, the green primary light field and the blue primary light field are adjusted respectively so that for multiple individual points on the image frame, the corresponding levels are reduced to the minimum value of the levels of the multiple individual points.

[0064] (8) The projection system of any one of (1) to (7), wherein the first image includes a reduction in chromaticity at at least one location at at least one edge of the image frame.

[0065] (9) The projection system according to any one of (1) to (8), wherein the second image is visually uniform across the image frame.

[0066] (10) The projection system according to any one of (1) to (9), wherein the smoothed maximum lower limit of the plurality of primary color light fields is a brightness distribution of the second image.

[0067] (11) A method for correcting an image provided by a light source configured to emit light in response to image data and an optical system configured to project the light emitted by the light source, the method comprising: receiving an input associated with a plurality of light values ​​corresponding to a plurality of primary color light fields; converting the input associated with the plurality of light values ​​into a plurality of projector primary color values; determining a gain map based on the plurality of projector primary color values; applying the gain map to the image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that the primary color mix is ​​the same across an image frame; and projecting the image with the image frame using the optical system, wherein a second image is corrected by the gain map.

[0068] (12) A method according to (11), wherein the optical system includes: an illumination optical device, which is configured to redirect light emitted by the light source to obtain redirected light; a digital micromirror device, which is configured to receive the redirected light from the illumination optical device and convert the redirected light into modulated light; and a projection optical device, which is configured to project the modulated light onto a screen.

[0069] (13) The method according to (11) or (12), further comprising projecting a first image in an image frame using the optical system, wherein the first image includes the plurality of primary color light fields.

[0070] (14) The method of any one of (11) to (13), wherein the input associated with a plurality of light values ​​of the first image is a photograph of the first image taken by a camera.

[0071] (15) The method of any one of (11) to (14), wherein applying the gain map to the image comprises modifying an image signal provided by the light source.

[0072] (16) The method according to any one of (11) to (15), wherein the plurality of primary color light fields include a red primary color light field, a green primary color light field, and a blue primary color light field.

[0073] (17) The method according to (16), wherein the levels of the red primary light field, the green primary light field, and the blue primary light field are adjusted respectively so that for multiple individual points on the image frame, the corresponding levels are reduced to the minimum value of the levels of the multiple individual points.

[0074] (18) The method of any one of (11) to (17), wherein the second image is visually uniform across the image frame.

[0075] (19) The method according to any one of (11) to (18), wherein the smoothed maximum lower limit of the plurality of primary color light fields is a brightness distribution of the second image.

[0076] (20) A non-transitory computer-readable medium storing instructions that, when executed by a processor of a projection system, cause the projection system to perform operations including the method according to any one of (11) to (19).

[0077] With respect to the processes, systems, methods, heuristics, etc. described herein, it should be understood that although the steps of such processes, etc. have been described as being performed in a particular ordered order, such processes may be practiced with the described steps performed in an order different from that described herein. It should further be understood that certain steps may be performed simultaneously, other steps may be added, or certain steps described herein may be omitted. In other words, the process descriptions herein are provided for the purpose of illustrating certain embodiments and should in no way be construed as limiting the claims.

[0078] Therefore, it should be understood that the above description is intended to be illustrative and not restrictive. By reading the above description, many embodiments and applications other than the examples provided will be apparent. The scope should not be determined with reference to the above description, but should be determined with reference to the full range of equivalents to which the appended claims and these claims are eligible for consideration. It is expected and desired that the technology discussed herein will develop in the future, and the disclosed systems and methods will be incorporated into such future embodiments. In a word, it should be understood that the present application can be modified and changed.

[0079] All terms used in the claims are intended to be given their broadest reasonable interpretations and ordinary meanings as understood by those skilled in the art described herein, unless an explicit indication to the contrary appears herein. In particular, use of singular articles such as "a," "the," "said," etc. should be understood to recite one or more of the indicated elements, unless a claim recites an explicit limitation to the contrary.

[0080] An abstract of the disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. This abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing detailed description, it can be seen that various features are combined together into various embodiments for the purpose of linking the disclosure together as a whole. The method of the present disclosure should not be interpreted as reflecting an intention that the claimed embodiments incorporate more features than those expressly recited in each claim. On the contrary, as reflected in the claims, the inventive subject matter lies in less than all the features of a single disclosed embodiment. Therefore, the appended claims are hereby incorporated into the detailed description, with each claim acting alone as a separately claimed subject matter.

Claims

1. A projection system, comprising: a light source configured to emit light in response to the image data; an optical system configured to project the light emitted by the light source; as well as A controller, the controller being configured to: receiving an input associated with a plurality of light values ​​of a first image corresponding to a plurality of primary color light fields, wherein the input associated with the plurality of light values ​​of the first image is a photograph of the first image taken by a camera, wherein the first image is a white image, and wherein the plurality of primary color light fields include a red primary color light field, a green primary color light field, and a blue primary color light field; converting the input associated with the plurality of light values ​​into a plurality of projector primary color values; determining a gain map based on the plurality of projector primary color values; applying the gain map to the first image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that primary color mixing is the same across an image frame, thereby generating a second image, wherein the level of the red primary color light field, the level of the green primary color light field, and the level of the blue primary color light field are adjusted, respectively, so that for each of a plurality of individual points on the image frame, each corresponding level of the point is reduced to a minimum value among the level of the red primary color light field, the level of the green primary color light field, and the level of the blue primary color light field at the point; and The second image is projected with the optical system, wherein the second image has been corrected by the gain map, and wherein the second image has a brightness distribution that is a smooth maximum lower bound of the plurality of primary color light fields.

2. The projection system according to claim 1, wherein: The optical system comprises: an illumination optical device configured to redirect the light emitted by the light source to obtain redirected light; a digital micromirror device configured to receive the redirected light from the illumination optics and convert the redirected light into modulated light; and Projection optics are configured to project the modulated light onto a screen.

3. The projection system according to claim 1 or claim 2, wherein: The controller is further configured to The first image is projected with the optical system, the first image comprising the plurality of primary color light fields.

4. The projection system according to claim 1 or claim 2, wherein: Applying the gain map to the first image includes modifying an image signal provided by the light source.

5. The projection system according to claim 1 or claim 2, wherein: The first image includes a reduction in chroma at at least one location at at least one edge of the image frame.

6. The projection system according to claim 1 or claim 2, wherein: The second image is visually uniform across the image frame.

7. A method of correcting a projected image provided by a light source configured to emit light in response to image data and an optical system configured to project the light emitted by the light source, the method comprising: receiving an input associated with a plurality of light values ​​of a first image corresponding to a plurality of primary color light fields, wherein the input associated with the plurality of light values ​​of the first image is a photograph of the first image taken by a camera, wherein the first image is a white image, and wherein the plurality of primary color light fields include a red primary color light field, a green primary color light field, and a blue primary color light field; converting the input associated with the plurality of light values ​​into a plurality of projector primary color values; determining a gain map based on the plurality of projector primary color values; applying the gain map to the first image to perform chromatic uniformity correction by adjusting the levels of the plurality of primary color light fields so that primary color mixing is the same across an image frame, thereby generating a second image, wherein the level of the red primary color light field, the level of the green primary color light field, and the level of the blue primary color light field are adjusted, respectively, so that for each of a plurality of individual points on the image frame, each corresponding level of the point is reduced to a minimum value among the level of the red primary color light field, the level of the green primary color light field, and the level of the blue primary color light field at the point; and The second image is projected with the optical system, wherein the second image has been corrected by the gain map, and wherein the second image has a brightness distribution that is a smooth maximum lower bound of the plurality of primary color light fields.

8. The method according to claim 7, wherein: The optical system comprises: an illumination optical device configured to redirect the light emitted by the light source to obtain redirected light; a digital micromirror device configured to receive the redirected light from the illumination optics and convert the redirected light into modulated light; and Projection optics are configured to project the modulated light onto a screen.

9. The method according to claim 7 or claim 8, further comprising: The first image is projected with the optical system, the first image comprising the plurality of primary color light fields.

10. The method according to claim 7 or claim 8, wherein: Applying the gain map to the first image includes modifying an image signal provided by the light source.

11. The method according to claim 7 or claim 8, wherein: The second image is visually uniform across the image frame.

12. A non-transitory computer readable medium storing instructions that, when executed by a processor of a projection system, cause the projection system to perform operations including the method of any one of claims 7 to 11.

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