Color calibration method and device, projection equipment and storage medium

Abstract

The invention discloses a color calibration method and device, projection equipment and a storage medium, and relates to the technical field of projection. The method comprises the following steps: carrying out white balance calibration under a target color gamut on projection equipment; the calibrated projection equipment sequentially projects a single-color picture of each color in the six original colors; obtaining the current color coordinates of the projected monochromatic pictures of each color in sequence through a color corrector; adjusting the color adjustment parameter corresponding to each color in the projection equipment until the current color coordinate of the monochromatic picture of each color projected again after the parameter adjustment is detected is matched with the standard color coordinate of the monochromatic picture of each color in the target color gamut, and obtaining the standard color adjustment parameter of each color in the projection equipment. Therefore, the projection equipment after white balance calibration can perform color calibration on the to-be-projected picture by using the standard color adjustment parameter corresponding to each color in the six original colors and then output the to-be-projected picture, so that the color accuracy of the projected picture is improved.

Description

Technical Field

[0001] This application relates to the field of projection technology, and in particular to a color calibration method, apparatus, projection device and storage medium. Background Technology

[0002] For projectors, given the varying light sources and complex color gamuts, accurately reproducing the colors of nature, enhancing the customer's experience of projector image quality, and ensuring consistent and accurate color reproduction have become pressing issues that need to be addressed. Summary of the Invention

[0003] This application proposes a color calibration method, apparatus, projection device, and storage medium to improve the accuracy of projected image colors.

[0004] In a first aspect, embodiments of this application provide a color calibration method, the method comprising: performing white balance calibration on a projection device under a target color gamut; sequentially projecting monochrome images of each of the original six colors onto the projection device after calibration; sequentially obtaining the current color coordinates of the monochrome images of each color projected using a colorimeter; adjusting the color adjustment parameters corresponding to each color in the projection device until the current color coordinates of the monochrome images of each color reprojected after the adjustment parameters are detected are matched with the standard color coordinates of the monochrome images of each color under the target color gamut to obtain standard color adjustment parameters for each color in the projection device, the standard color adjustment parameters being used for color calibration before projecting the image to be projected.

[0005] Secondly, this application provides a color calibration device, comprising: a white balance calibration module, a projection module, a color accuracy detection module, and a color calibration module. The white balance calibration module is used to perform white balance calibration on a projection device under a target color gamut. The projection module is used to sequentially project monochrome images of each of the original six colors onto the calibrated projection device. The color accuracy detection module is used to sequentially obtain the current color coordinates of the projected monochrome images of each color using a colorimeter. The color calibration module is used to adjust the color adjustment parameters corresponding to each color in the projection device until the current color coordinates of the reprojected monochrome images of each color after the adjustment parameters are detected are matched with the standard color coordinates of the monochrome images of each color under the target color gamut, thereby obtaining the standard color adjustment parameters for each color in the projection device. These standard color adjustment parameters are used for color calibration before projecting the image to be projected.

[0006] Thirdly, embodiments of this application provide a projection device, including: one or more processors; a memory; one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs are configured to perform the methods described above.

[0007] Fourthly, embodiments of this application provide a computer-readable storage medium storing program code that can be invoked by a processor to execute the methods described above.

[0008] The solution provided in this application involves performing white balance calibration on the projection device under the target color gamut. After calibration, the projection device sequentially projects monochrome images of each of the original six colors. A colorimeter sequentially obtains the current color coordinates of each projected monochrome image. The color adjustment parameters corresponding to each color in the projection device are adjusted until the current color coordinates of the reprojected monochrome image of each color are detected and matched with the standard color coordinates of each monochrome image under the target color gamut. This yields the standard color adjustment parameters for each color in the projection device, which are used for color calibration before projecting the image. Thus, the projection device, after white balance calibration, can utilize the standard color adjustment parameters corresponding to each of the original six colors to perform color calibration on the image before outputting it, thereby improving the color accuracy of the projected image. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A schematic diagram of the architecture of a color calibration system provided in one embodiment of this application is shown.

[0011] Figure 2 A schematic flowchart of a color calibration method provided in an embodiment of this application is shown.

[0012] Figure 3 A schematic diagram of the white balance calibration process provided in an embodiment of this application is shown.

[0013] Figure 4 A schematic flowchart of a color calibration method provided in another embodiment of this application is shown.

[0014] Figure 5 A schematic diagram of a standard point provided in an embodiment of this application is shown.

[0015] Figure 6 It shows Figure 4 A flowchart illustrating a sub-step of step S360 in one embodiment.

[0016] Figure 7 A schematic diagram of the data flow for color calibration provided in an embodiment of this application is shown.

[0017] Figure 8 This is a block diagram of a color calibration device provided according to an embodiment of this application.

[0018] Figure 9 This is a block diagram of a projection device for performing a color calibration method according to an embodiment of this application.

[0019] Figure 10 This is a storage unit in this application embodiment for storing or carrying program code that implements the color calibration method according to this application embodiment. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0021] It should be noted that some processes described in the specification, claims, and accompanying drawings of this application include multiple operations that appear in a specific order. These operations may not be performed in the order they appear herein, or they may be performed in parallel. Operation numbers such as S110, S120, etc., are merely used to distinguish different operations and do not represent any execution order. Furthermore, these processes may include more or fewer operations, and these operations may be performed sequentially or in parallel. Also, the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or server that includes a series of steps or sub-modules is not necessarily limited to those steps or sub-modules that are explicitly listed, but may include other steps or sub-modules that are not explicitly listed or that are inherent to such process, method, product, or device.

[0022] The inventors have proposed a color calibration method, apparatus, projection device, and storage medium. The color calibration method provided in the embodiments of this application will be described in detail below.

[0023] Please see Figure 1 , Figure 1 This illustration shows a schematic diagram of the architecture of a color calibration system according to an embodiment of this application. The color calibration system 10 may include a projection device 110 and a colorimeter 120. The projection device 110 includes a main control module 111 and an optical engine display module 112. The main control module 111 has data processing capabilities, and the optical engine display module 112 can perform color calibration on the projected image based on the color adjustment parameters output by the main control module 111 before outputting the result.

[0024] In some implementations, the projection device 110 first performs white balance calibration under the target color gamut. Further, after calibration, the projection device 110 can sequentially project monochrome images of each of the original six colors via the optical engine display module 112. The colorimeter 120 sequentially detects the current color coordinates of each projected monochrome image and transmits these coordinates to the main control module 111 in the projection device 110. Further, the main control module 111 can adjust the color adjustment parameters corresponding to each color until the current color coordinates of the reprojected monochrome image of each color after the adjustment parameters are detected match the standard color coordinates of each monochrome image under the target color gamut, thus obtaining the standard color adjustment parameters for each color in the projection device 110. These standard color adjustment parameters are used for color calibration before projecting the image to be projected.

[0025] Please refer to Figure 2 , Figure 2 This is a schematic flowchart illustrating a color calibration method provided in one embodiment of this application. The following will be combined with... Figure 2 The color calibration method provided in the embodiments of this application will be described in detail. This color calibration method may include the following steps:

[0026] Step S210: Perform white balance calibration on the projection device under the target color gamut.

[0027] In this embodiment, color gamut can be understood as the range of colors that a certain color model can represent, that is, the sum of colors that a display system can produce. Different color gamuts generally represent different ranges of colors; furthermore, the standard color coordinates of the same color are different in different color gamuts. Therefore, to achieve accurate display of screen colors in different color gamuts, at least the color adjustment parameters of the projection device must first be calibrated for different color gamuts. The target color gamut mentioned above can be a common color gamut such as REC709 or DCIP3, and this embodiment does not limit it.

[0028] Considering that an incorrect white balance on a projector can affect the accuracy of color display in other projected colors, thus impacting the overall color accuracy of the projected image, it's advisable to first calibrate the projector's white balance within the target color gamut. Only after achieving white balance calibration should subsequent color adjustment parameters be calibrated.

[0029] In some implementations, white balance calibration of a projection device under the target color gamut can be performed by first projecting a white image. A colorimeter is then used to detect the current color coordinates of the projected white image and determine if these coordinates match the standard color coordinates of the white image under the target color gamut. If they match, the projection device has reached the white balance standard; otherwise, it has not, and further white balance calibration is required to ensure accurate display of a pure white image under the target color gamut. Since white is obtained by mixing three primary colors of light: red (R), green (G), and blue (B), white balance calibration under the target color gamut can be performed by adjusting the brightness parameters of at least two of the red, blue, and green colors until the current color coordinates of the reprojected white image are found to match the standard color coordinates of the white image. This yields the standard color adjustment parameters for white balance adjustment in the projection device. The current color coordinates include the current x-coordinate value and the current y-coordinate value, while the standard color coordinates include the standard x-coordinate value and the standard y-coordinate value. The standard color coordinates of the white image are the color coordinates of a white image with 100% brightness within the target color gamut. Taking the target color gamut as REC709 as an example, the aforementioned standard color coordinates of the white image are (0.3127, 0.329), i.e. Figure 3 X in 标准 =0.3127, Y 标准 = 0.329. It should be noted that decreasing the brightness parameter corresponding to red will decrease the current horizontal coordinate value of the white screen, while the current vertical coordinate value of the white screen will remain essentially unchanged; decreasing the brightness parameter corresponding to green will increase the current horizontal coordinate value of the white screen, but by a small margin, while decreasing the current vertical coordinate value of the white screen; decreasing the brightness parameter corresponding to blue will increase both the current horizontal and vertical coordinate values ​​of the white screen.

[0030] like Figure 3 As shown, if the current horizontal coordinate value (i.e. Figure 3 X in 当前 ) is greater than the standard x-axis value (i.e. Figure 3 X in 标准 ), and the current ordinate value (i.e. Figure 3 Y in 当前 ) is greater than the standard ordinate value (i.e. Figure 3 Y in 标准 At this point, by reducing the brightness parameter corresponding to green, Y... 当前 =Y 标准 At this time, X 当前 It must be greater than X 标准However, reducing the brightness parameter corresponding to red will decrease the current horizontal coordinate value of the white image, while the current vertical coordinate value of the white image will remain essentially unchanged. Therefore, the brightness parameter corresponding to red can be further reduced to make X... 当前 =X 标准 .

[0031] Optionally, if the current x-coordinate value is greater than the standard x-coordinate value and the current y-coordinate value is less than the standard y-coordinate value, then the brightness parameter corresponding to blue is reduced, so that Y... 当前 =Y 标准 At this time, X 当前 It must be greater than X 标准 Similarly, reducing the brightness parameter corresponding to red will decrease the current horizontal coordinate value of the white screen, while the current vertical coordinate value of the white screen will remain essentially unchanged. Therefore, the brightness parameter corresponding to red can be further reduced to make X... 当前 =X 标准 .

[0032] Optionally, if the current x-coordinate value is less than the standard x-coordinate value, then the brightness parameter corresponding to blue is adjusted to make X... 当前 =X 标准 The system reads the current ordinate value of the projected white image after adjusting the brightness parameter corresponding to blue using a colorimeter. If the current ordinate value is detected to be less than the standard ordinate value, the brightness parameter corresponding to blue is reduced to make the current ordinate value equal to the standard ordinate value, thus obtaining the Y-axis value. 当前 =Y 标 Similarly, at this time X 当前 It must be greater than X 标准 Because decreasing the brightness parameter corresponding to red will decrease the current horizontal coordinate value of the white image, while the current vertical coordinate value of the white image will remain essentially unchanged. Therefore, the brightness parameter corresponding to red can be further decreased to make X... 当前 =X 标准 .

[0033] Optionally, if the current x-coordinate value is less than the standard x-coordinate value, then the brightness parameter corresponding to blue is adjusted to make X... 当前 =X 标准 The system reads the current ordinate value of the projected white image after adjusting the brightness parameter corresponding to blue using a colorimeter. If the current ordinate value is detected to be greater than the standard ordinate value, the brightness parameter corresponding to green is further adjusted to make the current ordinate value equal to the standard ordinate value, thus obtaining the Y... 当前 =Y 标Decreasing the brightness parameter corresponding to green will decrease the current vertical coordinate value of the white screen and slightly increase the current horizontal coordinate value of the white screen. That is, at this time, X... 当前 It must be greater than X 标准 Decreasing the brightness parameter corresponding to the red element will reduce the current horizontal coordinate value of the white element, while the current vertical coordinate value of the white element will remain essentially unchanged. Therefore, by further decreasing the brightness parameter corresponding to the red element, the current horizontal coordinate value can be reduced, ultimately resulting in a decrease in the X-axis value. 当前 =X 标 allow.

[0034] Step S220: The calibrated projection device sequentially projects a monochrome image of each of the original six colors.

[0035] Step S230: Use a colorimeter to sequentially obtain the current color coordinates of the monochrome image of each projected color.

[0036] In this embodiment, the original six colors include red, green, blue, cyan (Cyan, C), magenta (M), and yellow (Y). Understandably, after adjusting the RGB brightness parameters to enable the projection device to accurately project a white image within the target color gamut, further adjustments to the color adjustment parameters are needed to ensure the projection device accurately displays monochrome images of the three primary colors (red, green, and blue) in the RGB model, and accurately displays monochrome images of the three primary colors (cyan, magenta, and yellow) in the CMY model. Therefore, the calibrated projection device can sequentially project monochrome images of each of the original six colors, and obtain the current color coordinates of each projected monochrome image using a colorimeter. It then determines whether the current color coordinates of the monochrome image of each color are the same as the standard color coordinates of the monochrome image of that color in the target color gamut. If the current color coordinates of the monochrome image of each color are the same as the standard color coordinates of the monochrome image of that color in the target color gamut, it indicates that the projection device can accurately display the monochrome image of that color in the target color gamut. At this time, there is no need to adjust the color adjustment parameters for that color in the projection device, and the current color adjustment parameters for that color are determined as the standard color adjustment parameters for that color in the projection device.

[0037] Optionally, if the current color coordinates of the monochrome image of each color are different from the standard color coordinates of that monochrome image under the target color gamut, it indicates that there is a color difference between each color currently displayed by the projection device and each color under the target color gamut, meaning that the projection device cannot accurately display the original six colors under the target color gamut. In this case, it is necessary to adjust the color adjustment parameters of each of the original six colors in the projection device so that the projection device can accurately display each of the original six colors under the target color gamut.

[0038] Step S240: Adjust the color adjustment parameters corresponding to each color in the projection device until the current color coordinates of the monochrome image of each color reprojected after the adjustment parameters are detected, and match the standard color coordinates of the monochrome image of each color in the target color gamut, to obtain the standard color adjustment parameters for each color in the projection device. The standard color adjustment parameters are used for color calibration before the image to be projected is projected.

[0039] The color adjustment parameters for each color can include hue (HUE, H), saturation (S), and brightness (G). H represents the basic color attribute, the color name such as red or yellow; S refers to color purity, with higher values ​​indicating purer colors and lower values ​​indicating grayer colors, ranging from 0-100%; G ranges from 0-100%. By adjusting the hue and saturation parameters for each color in the projection device, the current color coordinates of the projected monochrome image of that color can be affected. That is, as the hue and saturation parameters change for each color, the current color coordinates of the projected monochrome image will also change. Therefore, before the projection device leaves the factory, after white balance calibration, the hue and brightness parameters for each color are adjusted until the current color coordinates of the re-projected monochrome image of each color are found to be the same as the standard color coordinates of the monochrome image of that color in the target color gamut. This yields the hue and brightness parameters for each color in the projection device. Furthermore, the brightness parameters for each color in the projection device will be adjusted so that the pure color image projected by the projection device not only has very small color deviation, but also achieves the set brightness.

[0040] In this embodiment, after white balance calibration of the projection device, the color adjustment parameters of each of the original six colors in the projection device are then calibrated to obtain standard color adjustment parameters. This allows the white balance-calibrated projection device to use the standard color adjustment parameters corresponding to each of the original six colors to perform color calibration on the projected image before outputting it, thereby improving the color accuracy of the projected image.

[0041] Please refer to Figure 4 , Figure 4 This is a schematic flowchart illustrating a color calibration method according to another embodiment of this application. The following will be combined with... Figure 4 The color calibration method provided in the embodiments of this application will be described in detail. This color calibration method may include the following steps:

[0042] Step S310: Perform white balance calibration on the projection device under the target color gamut.

[0043] In this embodiment, the specific implementation of step S310 can be found in the content of the foregoing embodiments, and will not be repeated here.

[0044] Step S320: For each of the original six colors, the calibrated projection device projects a first monochrome image according to the first hue parameter, the initial saturation parameter, and the initial brightness parameter, and projects a second monochrome image according to the second hue parameter, the initial saturation parameter, and the initial brightness parameter.

[0045] Step S330: For each of the original six colors, based on the current color coordinates of the first monochrome image and the second monochrome image of each color, determine the linear relationship of color change for each color.

[0046] In this embodiment, after the white balance calibration of the projection device in the target color gamut is completed, the monochrome images of each color in the original six colors (i.e., RGBCMY) will be output in sequence to perform color calibration on the monochrome images of each color projected by the projection device.

[0047] For example, taking the color calibration of a projector displaying a red monochrome image as an example, firstly, the calibrated projector projects a red monochrome image according to the first hue parameter (e.g., H1), initial saturation parameter (S0), and initial brightness parameter (G0). At this time, a colorimeter can be used to detect the current color coordinates of the red monochrome image currently projected by the projector, which can be denoted as RH1(xRH1, yRH1). Further, the calibrated projector projects a red monochrome image according to the second hue parameter (e.g., H2), initial saturation parameter (S0), and initial brightness parameter (G0). At this time, a colorimeter can be used to detect the current color coordinates of the red monochrome image currently projected by the projector, which can be denoted as RH2(xRH2, yRH2).

[0048] Furthermore, based on the linear relationship between the two points, we can derive the following two formulas to characterize the linear relationship of the color change of red:

[0049] H-H1 / H2-H1=y-yRH1 / yRH2-yRH1

[0050] H-H1 / H2-H1=x-xRH1 / xRH2-xRH1

[0051] Similarly, the linear formulas for the color changes of each of the original six colors, excluding red, can also be obtained in the same way, and will not be elaborated on here.

[0052] Step S340: Based on the linear relationship of color change for each color and the standard color coordinates of the first and second standard points of each color in the target color gamut, adjust the hue parameters corresponding to each color in the projection device to obtain the standard hue parameters for each color in the projection device.

[0053] In this embodiment, the first standard point RB1 and the second standard point RB2 for each color in the target color gamut can be understood as two points with different shades of the same color. Taking red from the original six colors as an example, the color coordinates of the first standard point RB1 can be represented as (xRB1, yRB1), and the color coordinates of the second standard point RB1 can be represented as (xRB2, yRB2). Since there is a linear relationship between the color coordinates of different colors of the same color in the same color gamut, specifically, it can be expressed by the following linear formula:

[0054] (y-yRB1) / (yRB2-yRB1)=(x-xRB1) / (xRB2-xRB1)

[0055] Taking the target color gamut REC709 as an example, the standard color coordinates RB1 of the first standard point of red in the REC709 color gamut can be specifically (0.64, 0.33), and the standard color coordinates of the second standard point can be specifically RB2 (0.56, 0.32). Based on this, substituting the standard color coordinates RB1 of the first standard point and the standard color coordinates of the second standard point of red into the above linear formula, we can obtain y = 0.125x + 0.25. For example, the first standard point and the second standard point can be... Figure 5 The two points shown.

[0056] Furthermore, substituting y = 0.125x + 0.25 back into the two formulas used to characterize the linear relationship of red color change, we can obtain the calculated relationship between the standard hue parameter of red and the current color coordinates of the first and second monochrome images measured above. This calculated relationship can be expressed by the following formula:

[0057] H=(H2-H1)*(xRH1+2-8yRH1) / [8*(yRH2-yRH1)-(xRH2-xRH1)]+H1

[0058] Thus, the standard hue parameters for red in the projection device can be obtained through this formula.

[0059] Similarly, the standard hue parameters for each of the original six colors other than red are obtained in the same way, and will not be listed in detail here.

[0060] It should be noted that the color coordinate standards for each color are different under different color gamuts, as shown in Table 1. Table 1 shows the standard color coordinates and brightness of the original six-color RGBCMY under the target color gamut REC709 color gamut, and Table 2 shows the standard color coordinates and brightness of the original six-color RGBCMY under the target color gamut DCIP3 color gamut.

[0061]

[0062] Table 1

[0063]

[0064] Table 2

[0065] Step S350: The projection device, after adjusting the hue parameters, projects a monochrome image of each color again.

[0066] Specifically, for each of the original six colors, a third monochrome image is projected according to the standard hue parameter, the first saturation parameter, and the initial brightness parameter of each color, and a fourth monochrome image is projected according to the standard hue parameter, the second saturation parameter, and the initial brightness parameter of each color.

[0067] Similarly, taking red from the original six colors as an example, the projection device can project a third monochromatic image of red according to the standard hue parameters (H standard), the first saturation parameter (S1), and the initial brightness parameter (G0) obtained from the linear color change relationship of red. At this point, a colorimeter can be used to detect the current color coordinates of the third monochromatic image of red projected by the projection device; these current color coordinates can be denoted as RS1(xRS1, yRS1). Furthermore, the projection device will also project a fourth monochromatic image of red according to the standard hue parameters (H standard), the second saturation parameter (S2), and the initial brightness parameter (G0). Again, a colorimeter will be used to detect the current color coordinates of the fourth monochromatic image of red projected by the projection device; these current color coordinates can be denoted as RS2(xRS2, yRS2).

[0068] Step S360: Adjust the saturation adjustment parameters corresponding to each color in the projection device until the current color coordinates of the monochrome image of each color after the adjustment parameters are detected are the same as the standard color coordinates of each color in the target color gamut, thereby obtaining the standard saturation parameters of each color in the projection device.

[0069] In some implementations, please refer to Figure 6 Step S360 may include the contents of steps S361 to S362:

[0070] Step S361: Based on the current color coordinates of the third monochrome image and the fourth monochrome image for each color, determine the linear relationship of saturation change for each color.

[0071] Taking red from the original six colors as an example, based on the linear relationship between two points and the current color coordinates of the third and fourth monochrome images of red, a formula can be obtained to characterize the linear relationship of red saturation change. The linear relationship of red saturation change can be understood as the linear relationship between the change in red saturation parameter and the resulting change in color coordinates. Specifically, the linear relationship of red saturation is expressed by either (S-S1) / (S2-S1)=(x-xRS1) / (xRS2-xRS1) or (S-S1) / (S2-S1)=(y-yRS1) / (yRS2-yRS1).

[0072] Similarly, the linear formulas for the saturation changes of each of the original six colors, excluding red, are obtained in the same way, and will not be elaborated on here.

[0073] Step S362: Based on the linear relationship of saturation change under the target color and the standard color coordinates of the first standard point of each color under the target color gamut, adjust the saturation parameter corresponding to each color in the projection device until the current color coordinates of the monochrome image of each color after the adjustment parameter is detected to be the same as the standard color coordinates of each color under the target color gamut, and obtain the standard saturation parameter of each color.

[0074] Taking the REC709 color gamut as an example, the standard color coordinates RB1 of the first standard point of red in the REC709 color gamut can be specifically (0.64, 0.33). Based on this, by substituting the standard color coordinates of the first standard point of red into the formula used to characterize the linear relationship of red saturation, the calculation relationship between the standard saturation parameter of red and the current color coordinates of the third and fourth monochrome images measured above can be obtained. This calculation relationship can be expressed by the following formula S=(0.64-xRS1) / (xRS2-xRS1)*(S2-S1)+S1 or the formula S=(0.33-yRS1) / (yRS2-yRS1)*(S2-S1)+S1.

[0075] Thus, the standard saturation parameter for red in the projection device can be obtained through this formula.

[0076] Similarly, the standard saturation parameters for each of the original six colors other than red are obtained in the same way, and will not be listed in detail here.

[0077] Step S370: For each of the original six colors, project a fifth monochrome image according to the standard hue parameter, the standard saturation parameter and the first brightness parameter of each color, and project a sixth monochrome image according to the standard hue parameter, the standard saturation parameter and the second brightness parameter of each color.

[0078] Similarly, taking red from the original six colors as an example, the projection device can project a fifth monochrome image of red according to the previously obtained standard hue parameter (Hj), standard saturation parameter (Sj), and first brightness parameter (G1=1). At this time, a colorimeter can be used to detect the current brightness of the fifth monochrome image of red projected by the projection device, which can be recorded as GR1. Furthermore, the projection device will also project a sixth monochrome image of red according to the standard hue parameter (Hj), standard saturation parameter (Sj), and second brightness parameter (G2). At this time, a colorimeter will again be used to detect the current brightness of the sixth monochrome image of red projected by the projection device, which can be recorded as RG2. That is, when G is 1, the colorimeter detects that the actual brightness of the monochrome red image output by the projection device is GR1; when G is G2, the colorimeter detects that the actual brightness of the monochrome red image output by the projection device is GR2.

[0079] Step S380: Determine the brightness change ratio parameter of each color in the projection device based on the current brightness of the fifth monochrome image of each color, the current brightness of the sixth monochrome image, the first brightness parameter, and the second brightness parameter.

[0080] Specifically, the brightness difference between the current brightness of the fifth monochrome image and the current brightness of the sixth monochrome image can be obtained, as well as the parameter difference between the first brightness parameter and the second brightness parameter. The ratio of the aforementioned brightness difference to the parameter difference is then used as the brightness change parameter for each color. Taking red in the original six colors as an example, the brightness change ratio parameter for red in the projection device can be expressed as (GR1-GR2) / (1-G2). This brightness change ratio parameter for red can be understood as the change in brightness of the actual projected red monochrome image caused by each unit adjustment of the G value of red in the projection device.

[0081] Step S390: Based on the current brightness of the white monochrome image after white balance is achieved, the standard brightness parameter of the target color, and the brightness change ratio parameter of the target color, adjust the brightness parameter of the projection device under the target color to obtain the standard brightness parameter of the projection device for each color.

[0082] Specifically, taking red from the original six colors and REC709 as the target color gamut as an example, the current brightness of the monochrome white image after white balance can be represented as GR3. Therefore, the target brightness value Gm = GR3 * 0.2127, where 0.2127 is the proportional brightness that the monochrome red image should achieve in the REC709 color gamut. Further, the formula for calculating the standard brightness parameter of red can be obtained: G = 1 - [(GR1 - GR3 * 0.2127) * (1 - G2)] / (GR1 - GR2). Here, GR1 - GR3 * 0.2127 can be understood as the change in the detected current brightness from GR1 to the target brightness value Gm. Further obtaining the ratio of this change value to the aforementioned proportional brightness parameter of red, we can obtain the value of G that, to make the current brightness of the monochrome red image currently projected by the projection device become Gm, requires a change in the value of G: (GR1 - Gm) ÷ [(GR1 - GR2) / (1 - G2)]. Furthermore, by obtaining the difference between the initial value of G (1) and the change value of G, the standard brightness parameters of the projection device for red can be obtained.

[0083] Thus, the standard brightness parameters for red in a projection device can be obtained using this formula.

[0084] Similarly, the standard brightness parameters for each of the original six colors other than red are obtained in the same way, and will not be listed in detail here.

[0085] In some implementations, after step S390, the projection device can acquire the image to be projected; and using the standard color adjustment parameters corresponding to each color, perform color calibration on the image to be projected before outputting it. Specifically, such as... Figure 7As shown, after complete 7-color calibration, i.e., after completing steps S310 to S390, the projection device stores the standard color calibration parameters for adjusting white balance and the standard color calibration parameters (HSG) for each of the original 7 colors locally. Further, the integrated circuit (IC) imports the HSG parameters for each of the 7 colors and outputs monochrome image data for each color under different parameters. Simultaneously, the digital light processing (DLP) system receives the front-end data and, in conjunction with the light source control unit, performs complete color calibration. The optical engine display module displays the calibrated image frame in real time and waits for the next frame to be displayed. In this way, color calibration for each frame of the projected image can be achieved, i.e., sub-animation calibration of color accuracy, resulting in better and more accurate reproduction of natural colors during projection. It should be noted that... Figure 7 The process of obtaining the HSG parameters of the 7-color image corresponds to the standard color adjustment parameters for obtaining white balance and the standard color adjustment parameters for the original six colors in this embodiment, which will not be described in detail here.

[0086] In this embodiment, the three elements of color—hue, saturation, and brightness—are adjusted. Combined with the linear relationship of the color gamut space, the intersection points of the seven primary colors (RGB, CMYW) are calculated linearly to determine the order and range of HSG adjustments. This allows for a one-step adjustment of the three-dimensional coordinates of the seven primary colors within the color gamut space, thus completing automated color accuracy calibration. This enables the projector to reproduce natural colors with better accuracy even under varying light sources and complex color gamuts, enhancing the user's image quality experience and ensuring consistent color accuracy across the machine.

[0087] Please refer to Figure 8 The diagram illustrates a structural block diagram of a color calibration device 400 according to an embodiment of this application. The device 400 may include: a white balance calibration module 410, a projection module 420, a color accuracy detection module 430, and a color calibration module 440.

[0088] The white balance calibration module 410 is used to perform white balance calibration on the projection device under the target color gamut.

[0089] The projection module 420 is used to project monochrome images of each of the original six colors sequentially onto the calibrated projection device.

[0090] The color accuracy detection module 430 is used to sequentially obtain the current color coordinates of the monochrome image of each projected color through a colorimeter.

[0091] The color calibration module 440 is used to adjust the color adjustment parameters corresponding to each color in the projection device until the current color coordinates of the monochrome image of each color after the adjustment parameters are detected are matched with the standard color coordinates of the monochrome image of each color in the target color gamut, so as to obtain the standard color adjustment parameters for each color in the projection device. The standard color adjustment parameters are used to perform color calibration before the image to be projected is projected.

[0092] In some implementations, the white balance calibration module 410 can be used to: project a white image; detect the current color coordinates of the projected white image using the colorimeter; if the current color coordinates of the white image are not the same as the standard color coordinates of the white image in the target color gamut, then adjust the brightness parameters corresponding to at least two of the colors red, blue, and green until the current color coordinates of the white image reprojected after the adjustment parameters are detected are the same as the standard color coordinates of the white image, thereby obtaining the standard color adjustment parameters for adjusting the white balance in the projection device.

[0093] In this mode, the current color coordinates include the current horizontal coordinate value and the current vertical coordinate value, and the standard color coordinates include the standard horizontal coordinate value and the standard vertical coordinate value. The white balance calibration module 410 can be specifically used to: if the current horizontal coordinate value is greater than the standard horizontal coordinate value and the current vertical coordinate value is greater than the standard vertical coordinate value, then reduce the brightness parameter corresponding to green and the brightness parameter corresponding to red; if the current horizontal coordinate value is less than the standard horizontal coordinate value and the current vertical coordinate value is less than the standard vertical coordinate value, then reduce the brightness parameter corresponding to blue and the brightness parameter corresponding to red; if the current horizontal coordinate value is greater than the standard horizontal coordinate value and the current vertical coordinate value is less than the standard vertical coordinate value, then reduce the brightness parameter corresponding to blue, the brightness parameter corresponding to green, and the brightness parameter corresponding to red.

[0094] In some embodiments, the color adjustment parameters include hue parameters, saturation parameters, and brightness parameters. The projection module 420 can be specifically used to: for each of the original six colors, the calibrated projection device projects a first monochrome image according to the first hue parameter, the initial saturation parameter, and the initial brightness parameter; and to project a second monochrome image according to the second hue parameter, the initial saturation parameter, and the initial brightness parameter.

[0095] In this mode, the color calibration module 440 may include: a color linearity relationship determination unit, a hue parameter adjustment unit, and a saturation parameter adjustment unit. The color linearity relationship determination unit can be used to determine the color change linearity relationship for each of the original six colors, based on the current color coordinates of the first monochrome image and the second monochrome image of each color. The hue parameter adjustment unit can be used to adjust the hue parameter corresponding to each color in the projection device according to the color change linearity relationship of each color and the standard color coordinates of the first and second standard points of each color in the target color gamut, to obtain the standard hue parameter for each color in the projection device. The projection module 420 can also be specifically used to reproject the monochrome image of each color after adjusting the hue parameter. The saturation parameter adjustment unit can be used to adjust the saturation adjustment parameter corresponding to each color in the projection device until the current color coordinates of the reprojected monochrome image of each color after detecting the adjustment parameter are the same as the standard color coordinates of each color in the target color gamut, to obtain the standard saturation parameter for each color in the projection device.

[0096] In some embodiments, the projection module 420 can also be specifically used to project a third monochrome image for each of the original six colors according to the standard hue parameter, first saturation parameter, and initial brightness parameter of each color, and to project a fourth monochrome image according to the standard hue parameter, second saturation parameter, and initial brightness parameter of each color. The saturation parameter adjustment unit can be specifically used to: determine the linear relationship of saturation change under each color based on the current color coordinates of the third monochrome image and the fourth monochrome image of each color; adjust the saturation parameter corresponding to each color in the projection device according to the linear relationship of saturation change under the target color and the standard color coordinates of the first standard point of each color under the target color gamut, until the current color coordinates of the monochrome image of each color reprojected after the adjustment parameter is detected are the same as the standard color coordinates of each color under the target color gamut, thus obtaining the standard saturation parameter of each color.

[0097] In some embodiments, the color calibration device 400 may further include a brightness calibration module. Specifically, the brightness calibration module may be used to adjust the saturation adjustment parameters corresponding to each color in the projection device until the current color coordinates of the reprojected monochrome image of each color after the adjustment parameters are detected are the same as the standard color coordinates of each color in the target color gamut, thereby obtaining the standard saturation parameters of the projection device for each color. Then, for each of the original six colors, a fifth monochrome image is projected according to the standard hue parameter, the standard saturation parameter, and the first brightness parameter of each color; a sixth monochrome image is projected according to the standard hue parameter, the standard saturation parameter, and the second brightness parameter of each color; the brightness change ratio parameter of the target color in the projection device is determined based on the current brightness of the fifth monochrome image, the current brightness of the sixth monochrome image, the first brightness parameter, and the second brightness parameter; and the brightness parameters of the projection device under the target color are adjusted based on the current brightness of the obtained white monochrome image after white balance is achieved, the standard brightness parameter of the target color, and the brightness change ratio parameter of the target color, thereby obtaining the standard brightness parameters of the projection device for each color.

[0098] In some embodiments, the color calibration device 400 may further include a projection image acquisition module. This projection image acquisition module is used to adjust the color adjustment parameters corresponding to each color in the projection device until the adjusted parameters are detected, and then match the current color coordinates of the monochrome image of each color reprojected with the standard color coordinates of the monochrome image of each color in the target color gamut to obtain the standard color adjustment parameters for each color in the projection device. These standard color adjustment parameters are used to acquire the image to be projected after color calibration before projection. The color calibration module 440 can be used to perform color calibration on the image to be projected using the standard color adjustment parameters corresponding to each color and then output the result.

[0099] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0100] In the several embodiments provided in this application, the coupling between modules can be electrical, mechanical, or other forms of coupling.

[0101] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0102] In summary, by adjusting the three elements of color—hue, saturation, and brightness—and considering the linear relationship of the color gamut, the intersection points of the seven primary colors (RGB, CMYW) are determined through linear calculations. This confirms the order and range of HSG adjustments, allowing for a one-step adjustment of the three-dimensional coordinates of the seven primary colors within the color gamut space, thus achieving automated color accuracy calibration. This enables projectors to reproduce natural colors with better accuracy even under varying light sources and complex color gamuts, enhancing the user's projector image quality experience and ensuring consistent color accuracy across the machine.

[0103] The following will combine Figure 9 This application describes a projection device.

[0104] Reference Figure 9 , Figure 9 The diagram shows a structural block diagram of a projection device 500 provided in an embodiment of this application. The above-described method provided in this embodiment of the application can be executed by the projection device 500.

[0105] The projection device 500 in this embodiment may include one or more of the following components: processor 501, memory 502, and one or more application programs, wherein the one or more application programs may be stored in memory 502 and configured to be executed by one or more processors 501, and the one or more programs are configured to perform the methods as described in the foregoing method embodiments.

[0106] Processor 501 may include one or more processing cores. Processor 501 connects to various parts within the projection device 500 using various interfaces and lines, and performs various functions and processes data of the projection device 500 by running or executing instructions, programs, code sets, or instruction sets stored in memory 502, and by calling data stored in memory 502. Optionally, processor 501 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). Processor 501 may integrate one or more of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the aforementioned modem can also be integrated into processor 501 and implemented using a separate communication chip.

[0107] The memory 502 may include random access memory (RAM) or read-only memory (ROM). The memory 502 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 502 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as touch functionality, sound playback functionality, image playback functionality, etc.), and instructions for implementing the various method embodiments described below. The data storage area may also store data created by the projection device 500 during use (such as the various correspondences described above).

[0108] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0109] In the several embodiments provided in this application, the coupling or direct coupling or communication connection between the modules shown or discussed may be an indirect coupling or communication connection through some interface, device or module, and may be electrical, mechanical or other forms.

[0110] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0111] Please refer to Figure 10 This diagram illustrates a structural block diagram of a computer-readable storage medium provided in an embodiment of this application. The computer-readable medium 600 stores program code that can be called by a processor to execute the methods described in the above method embodiments.

[0112] The computer-readable storage medium 600 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium 600 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 600 has storage space for program code 610 that performs any of the method steps described above. This program code can be read from or written to one or more computer program products. The program code 610 may be compressed, for example, in a suitable form.

[0113] In some embodiments, a computer program product or computer program is provided, which includes computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the steps in the above-described method embodiments.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A color calibration method, characterized by, The method comprises: white balance calibration of the projection device under a target color gamut; the calibrated projection device projects single-color pictures of each color of the original six colors in turn; the current color coordinates of each single-color picture projected are acquired by a colorimeter in turn; adjustment is made to the color adjustment parameters corresponding to each color in the projection device until the current color coordinates of each single-color picture re-projected after the adjustment parameters are detected match the standard color coordinates of each single-color picture under the target color gamut, obtaining the standard color adjustment parameters for each color in the projection device, which are used for color calibration before projection of a picture to be projected.

2. The method of claim 1, wherein, The white balance calibration of the projection device under a target color gamut comprises: projection of a white picture; detection of the current color coordinates of the projected white picture by the colorimeter; if the current color coordinates of the white picture are different from the standard color coordinates of the white picture under the target color gamut, adjustment is made to the luminance parameters corresponding to at least two of red, blue and green until the current color coordinates of the white picture re-projected after the adjustment parameters are detected are the same as the standard color coordinates of the white picture, obtaining the standard color adjustment parameters for adjusting the white balance in the projection device.

3. The method of claim 2, wherein, The current color coordinates comprise a current abscissa value and a current ordinate value, and the standard color coordinates comprise a standard abscissa value and a standard ordinate value; if the current color coordinates of the white picture are different from the standard color coordinates of the white picture under the target color gamut, adjustment is made to the luminance parameters corresponding to at least two of red, blue and green, which comprises: if the current abscissa value is greater than the standard abscissa value and the current ordinate value is greater than the standard ordinate value, the luminance parameter corresponding to green is decreased and the luminance parameter corresponding to red is decreased; if the current abscissa value is less than the standard abscissa value and the current ordinate value is less than the standard ordinate value, the luminance parameter corresponding to blue is decreased and the luminance parameter corresponding to red is decreased; if the current abscissa value is greater than the standard abscissa value and the current ordinate value is less than the standard ordinate value, the luminance parameter corresponding to blue is decreased and the luminance parameter corresponding to red is decreased; if the current abscissa value is less than the standard abscissa value and the current ordinate value is greater than the standard ordinate value, the luminance parameter corresponding to blue, the luminance parameter corresponding to green and the luminance parameter corresponding to red are decreased.

4. The method of claim 1, wherein, The color adjustment parameters comprise hue parameters, saturation parameters and luminance parameters, and the calibrated projection device projects single-color pictures of each color of the original six colors in turn, which comprises: for each color of the original six colors, the calibrated projection device projects a first single-color picture according to a first hue parameter, an initial saturation parameter and an initial luminance parameter, and projects a second single-color picture according to a second hue parameter, the initial saturation parameter and the initial luminance parameter; The color adjustment parameter corresponding to each color in the projection device is adjusted until the current color coordinates of the monochrome picture of each color re-projected after the adjustment parameter is detected match the standard color coordinates of the monochrome picture of each color under the target color gamut, and the standard color adjustment parameter for each color in the projection device is obtained, including: For each color in the original six colors, the color change linear relationship of each color is determined based on the current color coordinates of the first monochrome picture and the second monochrome picture of each color; According to the color change linear relationship of each color and the standard color coordinates of the first standard point and the second standard point of each color under the target color gamut, the hue parameter corresponding to each color in the projection device is adjusted to obtain the standard hue parameter for each color in the projection device; The projection device after the hue parameter is adjusted projects the monochrome picture of each color again; The saturation adjustment parameter corresponding to each color in the projection device is adjusted until the current color coordinates of the monochrome picture of each color re-projected after the adjustment parameter is detected are the same as the standard color coordinates of each color under the target color gamut, and the standard saturation parameter for each color in the projection device is obtained.

5. The method of claim 4, wherein, The projection device after the hue parameter is adjusted projects the monochrome picture of each color again, including: For each color in the original six colors, a third monochrome picture is projected according to the standard hue parameter, the first saturation parameter and the initial brightness parameter of each color, and a fourth monochrome picture is projected according to the standard hue parameter, the second saturation parameter and the initial brightness parameter of each color; The saturation adjustment parameter corresponding to each color in the projection device is adjusted until the current color coordinates of the monochrome picture of each color re-projected after the adjustment parameter is detected are the same as the standard color coordinates of each color under the target color gamut, and the standard saturation parameter for each color in the projection device is obtained, including: Based on the current color coordinates of the third monochrome picture and the fourth monochrome picture of each color, the saturation change linear relationship under each color is determined; According to the saturation change linear relationship under the target color and the standard color coordinates of the first standard point of each color under the target color gamut, the saturation parameter corresponding to each color in the projection device is adjusted until the current color coordinates of the monochrome picture of each color re-projected after the adjustment parameter is detected are the same as the standard color coordinates of each color under the target color gamut, and the standard saturation parameter of each color is obtained.

6. The method of claim 4, wherein, After the saturation adjustment parameter corresponding to each color in the projection device is adjusted until the current color coordinates of the monochrome picture of each color re-projected after the adjustment parameter is detected are the same as the standard color coordinates of each color under the target color gamut, and the standard saturation parameter for each color in the projection device is obtained, the method further includes: projecting a fifth monochromatic picture according to the standard hue parameter, the standard saturation parameter and a first brightness parameter of each color, and projecting a sixth monochromatic picture according to the standard hue parameter, the standard saturation parameter and a second brightness parameter of each color; determining a brightness variation ratio parameter of a target color in the projection device according to a current brightness of the fifth monochromatic picture of each color, a current brightness of the sixth monochromatic picture, a first brightness parameter and a second brightness parameter; adjusting the brightness parameter of the target color in the projection device based on the obtained current brightness of the monochromatic picture of the white color after the white balance is implemented, the standard brightness parameter of the target color and the brightness variation ratio parameter of the target color, to obtain the standard brightness parameter of each color in the projection device.

7. The method according to any one of claims 1 to 6, characterized in that, After the color adjustment parameters of each color in the projection device are adjusted until the current color coordinates of the monochromatic picture of each color after the adjustment parameters are re-projected match the standard color coordinates of the monochromatic picture of each color under the target color gamut, the standard color adjustment parameters of each color in the projection device are obtained, and the method further comprises: obtaining a to-be-projected picture; outputting the to-be-projected picture after color calibration is performed on the to-be-projected picture by using the standard color adjustment parameters corresponding to each color.

8. A color calibration apparatus, characterized by, The device comprises: a white balance calibration module configured to perform white balance calibration on a projection device under a target color gamut; a projection module configured to project monochromatic pictures of each color in original six colors by the calibrated projection device in sequence; a color coordinate detection module configured to obtain current color coordinates of the projected monochromatic pictures of each color by a colorimeter in sequence; a color calibration module configured to adjust color adjustment parameters corresponding to each color in the projection device until the current color coordinates of the monochromatic picture of each color after the adjustment parameters are re-projected match the standard color coordinates of the monochromatic picture of each color under the target color gamut, to obtain the standard color adjustment parameters of each color in the projection device, which are used for color calibration before a to-be-projected picture is projected.

9. A projection apparatus, characterized by comprising: The projection device comprises: one or more processors; a memory; one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs are configured to perform the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores program codes, and the program codes can be invoked and executed by a processor to perform the method according to any one of claims 1 to 7.

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