Color bearing acquisition method and system for FDM (frequency division multiplexing) color overlapping 3D (three-dimensional) printing process

Abstract

The invention relates to the technical field of 3D light-transmitting embossment printing, in particular to a color bearing obtaining method and system for an FDM color overlapping 3D printing process, and the color bearing obtaining method for the FDM color overlapping 3D printing process comprises the steps that light measurement is conducted on pure-color raw materials with different thicknesses, and basic absorption values of all the pure-color raw materials under different thicknesses are obtained; constructing a basic absorption model based on the acquired data; based on measurement of actual stacking color values and photometric data of the pure color raw materials under different thicknesses, color absorption increment values of all color layers under different thicknesses in the stacking color layers under different stacking modes are obtained, and a color absorption model is constructed based on the obtained data; obtaining an output color table based on the basic absorption model and the color absorption model in combination with the highlight absorption influence of the surface layer thickness; and based on a color approximation degree algorithm, matching the closest color corresponding to each RGB color needing to be expressed from the output color table. The method has the advantage that the CMYK stacked color precision is improved.

Description

Technical Field

[0001] The present application relates to the technical field of 3D translucent relief printing, and in particular to a color bearing acquisition method and system for FDM color stacking 3D printing process. Background Art

[0002] In today's artisan market, 3D translucent relief crafts are gaining increasing popularity with their unique visual effects and artistic appeal. FDM color stacking algorithms, a key technology in this field, play a vital role in achieving multi-color 3D translucent relief production.

[0003] The FDM color stacking algorithm originated from black and white translucent relief technology. By establishing a correspondence between relief thickness and image grayscale, the printed product appears black and white in backlit environments. This technology laid the foundation for the subsequent development of multicolor printing technology.

[0004] With the continuous advancement of multi-color printing technology, a form suitable for 3D printing relief has been derived from the CMYK algorithm used in color printing. In this form, cyan, magenta, yellow, and white are used for printing, corresponding to the four colors in the CMYK algorithm. The final product can appear as a color picture under backlight.

[0005] However, the actual CMYK translucent relief printing process has exposed numerous difficult-to-overcome challenges. First, the inherent limitations of the color stacking method lead to poor results when rendering complex colors. Complex colors often require the precise proportioning and superposition of multiple color components, but existing stacking methods cannot meet this high-precision requirement, resulting in the inability to faithfully and delicately reproduce complex color scenes.

[0006] Secondly, the color stacking of printed materials with a certain thickness presents fundamental optical differences compared to the color overlay absorption effect of ink-based CMYK printing. In traditional ink printing, color overlay absorption follows a relatively stable linear pattern, enabling relatively accurate rendering of various colors. However, in 3D translucent relief printing, material thickness has a complex effect on light propagation and color absorption, making algorithms based on linear thickness-to-CMYK value mapping difficult to achieve the desired results in practical applications. This difference in optical principles leads to inaccurate color rendering based on linear algorithms, which cannot meet the color accuracy requirements of 3D translucent relief crafts. Summary of the Invention

[0007] In order to improve the color accuracy of CMYK stacking, the present application provides a color bearing acquisition method for FDM color stacking 3D printing process.

[0008] In a first aspect, the present application provides a method for obtaining color bearing for an FDM color stacking 3D printing process, which adopts the following technical solution:

[0009] A method for obtaining color bearing capacity for an FDM color stacking 3D printing process, comprising the following steps:

[0010] Based on photometry of pure color raw materials of different thicknesses, basic absorption values ​​of each pure color raw material at different thicknesses are obtained, and a basic absorption model is constructed based on the obtained data;

[0011] Based on the measurement of actual stacked color values ​​and the photometric data of pure color materials at different thicknesses, the color absorption increment values ​​of each color layer in the stacked color layers at different thicknesses under different stacking methods are obtained, and a color absorption model is constructed based on the obtained data;

[0012] Based on the basic absorption model and the color absorption model, and combined with the highlight absorption effect of the surface thickness, the output color table is obtained;

[0013] Based on the color similarity algorithm, the closest color corresponding to each RGB color to be expressed is matched from the output color table.

[0014] In one embodiment: the basic absorption model is a piecewise linear model composed of multiple linear functions, the number of linear functions in the basic absorption model is the same as the number of pure color raw materials, the input of the basic absorption model is the color information and color layer thickness of the pure color raw materials, and the output is the basic absorption value.

[0015] In one embodiment: the color absorption model is a piecewise power function model composed of multiple power functions, the input of the color absorption model is the color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials, and the output is the color absorption increment value corresponding to each color layer.

[0016] In one embodiment, based on the difference in pure color raw materials, at least the color absorption increment value and the basic absorption value of each color layer only include the absorption value of at least one color.

[0017] In one embodiment, the step of obtaining the output color table based on the basic absorption model and the color absorption model and in combination with the highlight absorption effect of the surface thickness specifically includes:

[0018] Based on the basic absorption model and the color absorption model, the final output color values ​​corresponding to the stacking combination of all pure color raw materials are obtained;

[0019] Based on the grayscale value of the relief surface, the brightness absorption data of the top layer thickness is calculated;

[0020] Based on the final output color value and brightness absorption data, the output color table at different surface thicknesses under different stacking methods is calculated.

[0021] In one embodiment, the step of obtaining the final output color values ​​corresponding to the stacking combination of all pure color raw materials based on the basic absorption model and the color absorption model specifically includes:

[0022] Based on the stacking combination method, the color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials are obtained;

[0023] Using the color information and color layer thickness corresponding to the pure color raw materials as inputs to the basic absorption model, obtaining the basic absorption values ​​corresponding to all pure color raw materials;

[0024] The color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials are used as inputs of the color absorption model, and the color absorption increment value corresponding to each color layer is output;

[0025] The base absorption value is combined with the color absorption delta value to form the final output color value.

[0026] In one embodiment, the final output color value is in RGB format. During calculation, the final output color value is obtained by adding all basic absorption values ​​and color absorption increment values ​​based on the three colors of RGB.

[0027] In one embodiment, the step of calculating the brightness absorption data of the top layer thickness based on the grayscale value of the relief surface layer specifically includes:

[0028] Measure each point on the relief surface to obtain the corresponding RGB data;

[0029] Calculate the grayscale value through RGB data, and obtain the surface height of each relief point based on the grayscale value;

[0030] Based on the surface height, the corresponding offset value is obtained from the preset offset data table;

[0031] The brightness absorption data corresponding to the top layer is obtained by averaging the offset values ​​based on the surface height.

[0032] The brightness absorption data is obtained based on the measured data of the relief surface thickness and the calculated thickness of the surface layer.

[0033] In one embodiment, the color similarity algorithm may determine the similarity based on the variance value calculation of the grayscale mode component of the color, or based on the variance value calculation of the CEILAB color component.

[0034] In a second aspect, the present application provides a method for obtaining color bearing for an FDM color stacking 3D printing process, which adopts the following technical solution:

[0035] A color bearing acquisition system for FDM color stacking 3D printing process, characterized by comprising:

[0036] The basic absorption data acquisition and modeling module is used to measure the photometry of pure color raw materials of different thicknesses, obtain the basic absorption value of each pure color raw material at different thicknesses, and build a basic absorption model based on the acquired data;

[0037] The post-color layer absorption data acquisition and modeling module is used to measure the actual stacked color value, obtain the color absorption increment value of the post-color layer at different thicknesses in the stacked color layers under different stacking methods, and build a color absorption model of the post-color layer based on the acquired data;

[0038] Output color table generation module, used to generate output color table based on basic absorption model and color absorption model, while taking into account the highlight absorption effect of surface thickness;

[0039] The color matching module is used to match the closest color corresponding to each RGB color to be expressed from the output color table based on the color similarity algorithm.

[0040] To sum up, the present application has the following beneficial effects: it can print out more accurate colors using the CMYK stacking method, accurately restore the full color gamut of colors, and upgrade the visual iteration of the translucent relief to achieve a more three-dimensional, natural, precise and realistic overall effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is the original printed image of the two-dimensional image;

[0042] Figure 2 It is a work rendering based on the existing technology of printing the original picture;

[0043] Figure 3 It is a work rendering based on the existing technology of printing the original picture;

[0044] Figure 4 This is the rendering of the work based on the printed original image;

[0045] Figure 5 This is a framework diagram of the color bearing acquisition system for the FDM color stacking 3D printing process according to this embodiment;

[0046] Figure 6 This is a flow chart of a method for obtaining color bearing capacity for FDM color stacking 3D printing process.

[0047] In the figure, 10, basic absorption data acquisition and modeling module; 20, post-color layer absorption data acquisition and modeling module; 30, output color table generation module; 40, color matching module. DETAILED DESCRIPTION

[0048] The present application is further described in detail below with reference to the accompanying drawings.

[0049] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. However, it should be understood by those skilled in the art that the present application can be implemented without these details. In some cases, in order to avoid unnecessary descriptions that make various aspects of the present application obscure, the well-known methods, processes, systems, components and / or circuits that have been described at a higher level will not be described in detail. It is obvious to those skilled in the art that various changes can be made to the embodiments disclosed in the present application, and the general principles defined in the present application can be applied to other embodiments and application scenarios without departing from the principles and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but conforms to the broadest scope consistent with the scope claimed for protection in the present application.

[0050] It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] In the description of this application, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0052] In the description of this application, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any combination in one or more embodiments or examples.

[0053] In this embodiment, based on the following existing 3D light-transmitting relief printing technology, Figure 1The two-dimensional image in the figure is used as the original printing image, and compared with the effect image formed by the corresponding printing technology for explanation.

[0054] Among existing 3D translucent relief printing technologies, the MakerLab solution is the most commonly used. This approach is based on the original ColorLithophaneMaker. The algorithm is derived from a related algorithm found on GitHub. Tuozhu's MakerLab optimizations have since achieved even better results than the original algorithm.

[0055] Works using this technology include Figure 2 As shown, the relief's three-dimensional effect is acceptable, but there are significant flaws in the color, mainly manifested in the relatively serious imbalance in color rendering.

[0056] The performance of dark colors is relatively good, basically restoring the main color of the character itself, making the overall color relatively bright, especially the darker colors, the performance effect is better, but the light colors are expressed very poorly.

[0057] As you can see from the reference image, the original light colors have been largely transformed into white, which makes the light-colored face, hair, and background look unfriendly. Some light-colored areas are directly overexposed, which is inconsistent with the overall effect of light colors and dark clothes.

[0058] The source of this technical shortcoming lies in the compromise of inaccurate color representation within this process. While the linear overlay algorithm can render some darker colors more vividly, it cannot render lighter colors with fine detail. Therefore, the algorithm compromises the mapping of lighter colors and more detailed colors.

[0059] At the same time, because the linear superposition algorithm is used, the red color gamut is expressed well, which is close to the actual effect of simulating linear superposition, but the gray and yellow expressions have large errors.

[0060] The LTR3 algorithm is the third version of the LTR relief algorithm. This algorithm has different branch versions and achieves a stronger three-dimensional effect.

[0061] Works using this technology include Figure 3 As shown, the color rendering is closer to the original image than the original algorithm. From the reference image, the overall effect and the close-up of the face are not so pale, the blush is more natural, and the background trees are not so black, showing a certain level of similarity to the original image. The hair color is also lighter.

[0062] However, the overly light highlights sometimes have a white pop. The processing of dark colors causes discoloration, with red failing to appear purple, and the light brown background is overexposed. In the light areas, the hair and eyes are a bit too light, resulting in a slight blurring of the face.

[0063] The main drawback of this algorithm is that, despite expanding the color carrying capacity and color gamut coverage during the LTR3 algorithm phase, and fine-tuning the offset between the actual material color and the algorithm's ideal color through experimentation, the overall algorithm remains a linear stacking algorithm. Linear stacking is essentially an approximate algorithm. If parameters favor lighter colors, darker colors will inevitably be distorted, and vice versa.

[0064] Based on the above, we can see that the MakerLab solution compromises dark colors more, while the LTR3 solution compromises light colors more, and they cannot achieve relative accuracy in the full color gamut.

[0065] In order to achieve relative accuracy in the full color gamut, the visual iteration of the light-transmitting relief is upgraded to achieve a more three-dimensional, natural, accurate and realistic overall effect. This embodiment discloses a color bearing acquisition system for FDM color stacking 3D printing process, wherein: Figure 4 This is a work under the technology of this embodiment.

[0066] like Figure 5 As shown, a color bearing acquisition system for FDM color stacking 3D printing process includes a basic absorption data acquisition and modeling module 10, a post-color layer absorption data acquisition and modeling module 20, an output color table generation module 30 and a color matching module 40.

[0067] The basic absorption data acquisition and modeling module 10 is used to measure the light of pure color materials of different thicknesses, obtain the basic absorption value of each pure color material at different thicknesses, and construct a basic absorption model based on the obtained data.

[0068] The post-color layer absorption data acquisition and modeling module 20 is used to obtain the color absorption increment value of each color layer in the stacked color layers at different thicknesses under different stacking methods based on the measurement of the actual stacked color value and the photometric data of the pure color raw materials at different thicknesses, and to build a color absorption model based on the acquired data.

[0069] The output color table generating module 30 is used to generate an output color table based on the basic absorption model and the color absorption model, while taking into account the highlight absorption effect of the surface thickness.

[0070] The color matching module 40 is used to match the closest color corresponding to each RGB color to be expressed from the output color table based on a color similarity algorithm.

[0071] like Figure 6As shown, this embodiment also provides a color bearing acquisition method for FDM color stacking 3D printing process, which includes the following steps:

[0072] S200 , based on photometry of pure color raw materials of different thicknesses, obtain basic absorption values ​​of each pure color raw material at different thicknesses, and construct a basic absorption model based on the obtained data.

[0073] The pure color raw materials referred to in this embodiment only refer to non-white raw materials such as C color / M color / Y color, among which C color is cyan (Cyan), M color is magenta (Magenta), and Y color is yellow (Yellow). White is mainly used as the printing raw material for the bottom and top layers, and white theoretically does not participate in color absorption. Therefore, it is not a raw material that needs to be detected and calculated for absorption value in this embodiment.

[0074] Specifically, the basic absorption model in this step is a piecewise linear model composed of multiple linear functions. The number of linear functions in the basic absorption model is the same as the number of pure color raw materials. The basic absorption model takes the color information and color layer thickness of the pure color raw materials as input, and finally outputs the basic absorption value, wherein the color information is used to select the linear function, and the color layer thickness is used to generate the basic absorption value in the input linear function.

[0075] The principle behind forming a linear function in this step is based on the fact that color absorption curves are linear under CMYK printing conditions. For example, one part of color C corresponds to one part of color R absorption, and one part of color M corresponds to one part of color G absorption. This is the basis of existing CMYK color printing.

[0076] S400, based on the measurement of actual stacked color values ​​and the photometric data of pure color materials at different thicknesses, obtain the color absorption increment value of each color layer in the stacked color layers at different thicknesses under different stacking methods, and build a color absorption model based on the obtained data.

[0077] Specifically, the color absorption model in this step is a piecewise power function model composed of multiple power functions. The input of the color absorption model is the color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials. The output is the color absorption increment value corresponding to each color layer.

[0078] Among them, the color information of the pure color raw materials and the stacking order of the pure color raw materials are used as the basis for power function screening, and the color layer thickness is used to generate the basic absorption value in the power function.

[0079] In the above steps, obtaining the color information of the pure color raw materials refers to obtaining which pure color raw materials are used to form the color layer in the corresponding stacking combination. The stacking order refers to the order in which each pure color raw material is stacked, that is, the order in which the color layers are formed.

[0080] Furthermore, due to differences in pure color raw materials, each color layer's color absorption increment and base absorption values ​​each include the absorption value of at least one color. For example, color C actually absorbs both R and G, while color M absorbs both B and G. Since color Y's absorption of R and G is essentially negligible, only the absorption of color B is calculated. R, G, and B correspond to three RGB values, respectively.

[0081] Therefore, when the basic absorption model calculates the color layer formed by the C color, the basic absorption values ​​of the R color and the G color will be output at the same time; when calculating the color layer formed by the M color, the basic absorption values ​​of the B color and the G color will be output at the same time; when calculating the color layer formed by the Y color, the basic absorption value of the B color will be output at the same time.

[0082] Correspondingly, when the color absorption model calculates the color layer formed by stacking colors C and M, the color layer formed by color C will output the color absorption increment values ​​of colors R and G at the same time, and the color layer formed by color M will output the color absorption increment values ​​of colors B and G at the same time. Similarly, the color absorption increment values ​​corresponding to various stacking methods can be derived by analogy.

[0083] S600: Based on the basic absorption model and the color absorption model, and in combination with the highlight absorption effect of the surface thickness, an output color table is obtained.

[0084] In one embodiment, step S600 specifically includes the following steps:

[0085] Based on the basic absorption model and the color absorption model, the final output color values ​​corresponding to the stacking combination of all pure color raw materials are obtained;

[0086] Based on the grayscale value of the relief surface, the brightness absorption data of the top layer thickness is calculated;

[0087] Based on the final output color value and brightness absorption data, the output color table at different surface thicknesses under different stacking methods is calculated.

[0088] In another embodiment, based on the basic absorption model and the color absorption model, the step of obtaining the corresponding final output color values ​​of all pure color raw material stacking combinations specifically includes:

[0089] Based on the stacking combination method, the color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials are obtained;

[0090] The color information and color layer thickness corresponding to the pure color raw materials are used as inputs of the basic absorption model to obtain the basic absorption values ​​corresponding to all pure color raw materials;

[0091] The color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials are used as inputs of the color absorption model, and the color absorption increment value corresponding to each color layer is output;

[0092] The base absorption value is combined with the color absorption delta value to form the final output color value.

[0093] In this embodiment, the final output color value is in RGB format. Therefore, during calculation, the final output color value is obtained by adding all basic absorption values ​​and color absorption increment values ​​based on the three colors of RGB.

[0094] Taking the stacking of C and M as an example, C will absorb R and G, and M will absorb B and G. Therefore, the calculation formulas for the three colors RGB are as follows:

[0095] The final output color corresponding to R absorption = the basic absorption value of R absorption corresponding to the C layer + the color absorption increment value of R absorption corresponding to the C layer.

[0096] The final output color corresponding to G absorption = the basic absorption value of G absorption corresponding to the M layer + the color absorption increment value of G absorption corresponding to the M layer + the basic absorption value of G absorption corresponding to the C layer + the color absorption increment value of G absorption corresponding to the C layer.

[0097] The final output color corresponding to B absorption = the basic absorption value of B absorption corresponding to the M layer + the color absorption increment value of B absorption corresponding to the M layer.

[0098] In another embodiment, the step of calculating the brightness absorption data of the top layer thickness based on the grayscale value of the relief surface layer specifically includes:

[0099] Measure each point on the relief surface to obtain the corresponding RGB data;

[0100] Calculate the grayscale value through RGB data, and obtain the surface height of each relief point based on the grayscale value;

[0101] Based on the surface height, the corresponding offset value is obtained from the preset offset data table;

[0102] The brightness absorption data corresponding to the top layer is obtained by averaging the offset values ​​based on the surface height.

[0103] In this embodiment, the gray value Gray=0.299R+0.587G+0.144*B, and the calculated gray value can be converted into the surface height of each relief point.

[0104] Among them, there will be a large number of repeated values ​​in the obtained surface height. Therefore, when obtaining the offset value, there is no need to obtain it repeatedly. You only need to leave different surface heights to obtain the corresponding offset value.

[0105] Then divide the obtained offset value by the surface height to get the average offset value, and then multiply it by the average offset value based on the data of the top printing thickness to get the brightness absorption value of the point.

[0106] The brightness absorption data corresponding to the top layer can be formed by matching all surface heights and brightness absorption values ​​one by one. In order to facilitate subsequent search and use, the brightness absorption data can be recorded in the form of a table.

[0107] S800: Based on a color similarity algorithm, the closest color corresponding to each RGB color to be expressed is matched from the output color table.

[0108] The color similarity algorithm may be based on the variance value calculation of the grayscale mode component of the color, or based on the variance value calculation of the CEILAB color component to determine the similarity.

[0109] The familiarity determination is described using two colors whose RGB data are (R1, G1, B1) and (R2, G2, B2) using the two familiarity determination methods described above.

[0110] In the grayscale component mode, the similarity between two colors is:

[0111]

[0112] In the CEILAB color component method, the RGB data must first be divided into the CIELAB color space, which are (L1 * , a1, b1), (L2*, a2, b2), and then calculate the similarity between the two colors:

[0113]

[0114] Of the two familiarity determination methods mentioned above, the computational complexity of the grayscale component method is significantly reduced compared to the CEILAB color component method. However, the familiarity determination accuracy of the CEILAB color component method is slightly higher than that of the grayscale component method.

[0115] The embodiments of this specific implementation method are all preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A color bearing acquisition method for FDM color stacking 3D printing process, characterized in that: The following steps are involved: Based on photometry of pure color raw materials of different thicknesses, basic absorption values ​​of each pure color raw material at different thicknesses are obtained, and a basic absorption model is constructed based on the obtained data; Based on the measurement of actual stacked color values ​​and the photometric data of pure color materials at different thicknesses, the color absorption increment values ​​of each color layer in the stacked color layers at different thicknesses under different stacking methods are obtained, and a color absorption model is constructed based on the obtained data; Based on the basic absorption model and the color absorption model, and combined with the highlight absorption effect of the surface thickness, the output color table is obtained; Based on the color similarity algorithm, the closest color corresponding to each RGB color to be expressed is matched from the output color table.

2. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 1 is characterized by: The basic absorption model is a piecewise linear model composed of multiple linear functions. The number of linear functions in the basic absorption model is the same as the number of pure color raw materials. The input of the basic absorption model is the color information and color layer thickness of the pure color raw materials, and the output is the basic absorption value.

3. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 2 is characterized by: The color absorption model is a piecewise power function model composed of multiple power functions. The input of the color absorption model is the color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials. The output is the color absorption increment value corresponding to each color layer.

4. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 3 is characterized by: Based on the difference of pure color raw materials, at least the color absorption increment value and the basic absorption value of each color layer only contain the absorption value of at least one color.

5. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 1, characterized in that: The step of obtaining the output color table based on the basic absorption model and the color absorption model and in combination with the highlight absorption effect of the surface thickness specifically includes: Based on the basic absorption model and the color absorption model, the final output color values ​​corresponding to the stacking combination of all pure color raw materials are obtained; Based on the grayscale value of the relief surface, the brightness absorption data of the top layer thickness is calculated; Based on the final output color value and brightness absorption data, the output color table at different surface thicknesses under different stacking methods is calculated.

6. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 5, characterized in that: The step of obtaining the final output color values ​​corresponding to the stacking combination of all pure color raw materials based on the basic absorption model and the color absorption model specifically includes: Based on the stacking combination method, the color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials are obtained; Using the color information and color layer thickness corresponding to the pure color raw materials as inputs to the basic absorption model, obtaining the basic absorption values ​​corresponding to all pure color raw materials; The color information of the pure color raw materials, the stacking order of the corresponding pure color raw materials, and the color layer thickness of the corresponding pure color raw materials are used as inputs of the color absorption model, and the color absorption increment value corresponding to each color layer is output; The base absorption value is combined with the color absorption delta value to form the final output color value.

7. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 6, characterized in that: The final output color value is in RGB format. During calculation, the final output color value is obtained by adding all basic absorption values ​​and color absorption increment values ​​based on the three colors of RGB.

8. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 5, characterized in that: The step of calculating the brightness absorption data of the top layer thickness based on the grayscale value of the relief surface layer specifically includes: Measure each point on the relief surface to obtain the corresponding RGB data; Calculate the grayscale value through RGB data, and obtain the surface height of each relief point based on the grayscale value; Based on the surface height, the corresponding offset value is obtained from the preset offset data table; The brightness absorption data corresponding to the top layer is obtained by averaging the offset values ​​based on the surface height.

9. The color bearing acquisition method for FDM color stacking 3D printing process according to claim 1, characterized in that: The color similarity algorithm may determine the similarity based on the variance value calculation of the grayscale mode component of the color, or based on the variance value calculation of the CEILAB color component.

10. A color bearing acquisition system for FDM color stacking 3D printing process, characterized in that: include: A basic absorption data acquisition and modeling module (10) is used to measure the light of pure color materials of different thicknesses, obtain the basic absorption value of each pure color material at different thicknesses, and construct a basic absorption model based on the obtained data; A post-color layer absorption data acquisition and modeling module (20) is used to acquire the color absorption increment value of each color layer at different thicknesses in the stacked color layers under different stacking methods based on the measurement of the actual stacked color value and the photometric data of the pure color raw materials at different thicknesses, and to construct a color absorption model based on the acquired data; An output color table generation module 30 is used to generate an output color table based on the basic absorption model and the color absorption model, while taking into account the highlight absorption effect of the surface thickness; The color matching module (40) is used to match the closest color corresponding to each RGB color to be expressed from the output color table based on a color similarity algorithm.

Images