A high-definition structural color image replication method based on cross-scale structure

Abstract

The application discloses a high-definition structural color image copying method based on a cross-scale structure. In the process of copying the image, elliptical vibration is applied to an ultrasonic elliptical vibrating tool, and cosine vibration is applied to a workpiece, so that a grating micro-pit array is cut on the surface of the workpiece. The grating micro-pit array is formed by superimposing a nanometer grating array and a micro-pit array, and through the complex optical effect between the nanometer grating array and the micro-pit array, more rich colors can be presented. In the process of machining, the cutting process parameters of the ultrasonic elliptical vibrating tool can be controlled according to the hue of the original image, and the vibration trajectory of the workpiece can be controlled according to the saturation and brightness of the original image, so as to adjust the grating pitch of the nanometer grating array and the depth-width ratio of the micro-pit cross-section profile, realize the two-dimensional regulation of the grating micro-pit array feature structure on the structural color, make the structural surface present an image with more rich colors, and more accurately copy the required high-definition structural color image.

Description

Technical Field

[0001] This invention relates to the field of structural color processing technology, and more specifically to a method for replicating high-definition structural color images based on cross-scale structures. Background Technology

[0002] Many structural colors exist in nature, such as the colors on the surfaces of butterfly wings, peacock feathers, and beetle shells. These colors are not formed by pigments or the absorption of specific wavelengths of light, but rather by the complex optical interactions between the micro- and nano-structures of structural surfaces and visible light. They offer advantages such as high resolution, colorfastness, environmental friendliness, and iridescent effects, and have broad prospects in fields such as information encryption, intelligent sensing, and anti-counterfeiting.

[0003] Currently, various processes exist that can precisely fabricate micro- and nano-structures on metal surfaces to create specific images. For example, ultrasonic elliptical vibration cutting technology based on controlled cutting speed can fabricate nano-grating arrays on metal surfaces to produce the desired color images. However, the structural colors produced by nano-grating arrays are not rich enough, and the current processing technology lacks sufficient control. The hue, saturation, and brightness of the fabricated structural color images do not closely match the original images, making it impossible to accurately reproduce the required high-definition structural color images. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the present invention aims to provide a method for replicating high-definition structural color images based on cross-scale structures. This method enables two-dimensional control of the structural colors of structural surfaces, allowing structural surfaces to present images with richer colors and enabling more accurate replication of the required high-definition structural color images.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: a method for replicating high-definition structural color images based on cross-scale structures, comprising the following steps:

[0006] Step S100: Mesh the original image pixels to obtain a pixel matrix composed of multiple pixel units distributed along the nominal cutting direction X and the feed direction Y, and extract the hue matrix H, saturation matrix S and brightness matrix V from the pixel matrix.

[0007] Step S200: Use an ultrasonic elliptical vibrating cutter to perform row-by-row cutting on the surface of the workpiece. After each row of pixel units is cut and processed along the X direction, the ultrasonic elliptical vibrating cutter advances along the Y direction by the distance of one pixel unit and continues to cut and process the next row of pixel units until all pixel units in the pixel matrix of step S100 are cut and processed to obtain a replica image.

[0008] In the process of row-by-row cutting, the ultrasonic elliptical vibrating tool is provided with elliptical vibration of the XOZ plane to cut and process a nano-grating array on the workpiece surface, and the workpiece is provided with cosine vibration of the XOZ plane to cut and process a micro-pit array on the workpiece surface. The grating micro-pit array formed by the superposition of the nano-grating array and the micro-pit array can present a replicated image.

[0009] In this context, the Z direction is the cutting depth direction, and each pixel unit of the pixel matrix corresponds to a grating micro-pit. A grating micro-pit is formed by superimposing a nano grating array and a micro-pit with a cosine profile XOZ cross section. The length of each micro-pit is equal to the pixel size of the corresponding pixel unit along the X direction.

[0010] In the process of line-by-line cutting, the cutting process parameters of the ultrasonic elliptical vibrating tool in step S200 are adjusted according to the hue matrix H, and the vibration trajectory of the workpiece in step S200 is adjusted according to the saturation matrix S and the brightness matrix V.

[0011] Compared to existing technologies, the advantages of this invention are as follows: In the process of image replication, this method applies elliptical vibration of the XOZ plane to an ultrasonic elliptical vibrating tool and cosine vibration of the XOZ plane to the workpiece, thereby cutting and machining a grating micro-pit array on the workpiece surface to reproduce the replicated image. The grating micro-pit array is composed of a superposition of a nano-grating array and a micro-pit array. Through the complex optical interaction between the nano-grating array and the micro-pit array, richer colors can be presented. Furthermore, during processing, the cutting parameters of the ultrasonic elliptical vibrating tool can be adjusted according to the hue of the original image, and the vibration trajectory of the workpiece can be adjusted according to the saturation and brightness of the original image. This allows for adjustment of the grating spacing of the nano-grating array and the aspect ratio of the micro-pit cross-section, thereby achieving two-dimensional control of the structural color by the characteristic structure of the grating micro-pit array. This results in a more colorful image on the structural surface and more accurate replication of the required high-definition structural color image.

[0012] The above-mentioned method for replicating high-definition structural color images based on cross-scale structures controls the cutting process parameters of the ultrasonic elliptical vibration tool through the following steps:

[0013] Step S110: Convert the hue value H into the wavelength λ of the structural color using the following formula (1):

[0014]

[0015] Step S120: Convert the light wavelength λ into the grating spacing S of the nanograting array using the following formula (2). nm :

[0016]

[0017] Where N is the diffraction order, θ1 is the incident angle of white light, and θ2 is the observation angle;

[0018] Step S130: Select the vibration frequency f of the ultrasonic elliptical vibrating tool. e The nominal cutting speed v of the ultrasonic elliptical vibrating tool is determined by the following formula (3):

[0019] S nm =v / f e (3)

[0020] The above-mentioned method for replicating high-definition structural color images based on cross-scale structures controls the vibration trajectory of the workpiece through the following steps:

[0021] Step S140: Convert saturation S and brightness V into parameter SV using the following formula (4):

[0022] SV=a×S+(1-a)×V⑷;

[0023] Where 'a' is the weight of saturation, ranging from 0 to 1;

[0024] Step S150: Determine the depth-to-width ratio A of the micro-pit using the following formula (5). r :

[0025] A r = (1-SV)×A max (5)

[0026] Among them, A max This represents the maximum aspect ratio of the micro-pit;

[0027] Step S160: Based on the pixel size p of the pixel unit along the X direction L Determine the length l of the micropit cos The depth h of the micro-pit is determined by the following formula (6). cos :

[0028] A r =h cos / l cos (6)

[0029] Step S170: Obtain the vibration trajectory of the workpiece using the following formula (7):

[0030]

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0032] Figure 1 This is a process flow diagram of the replication method according to Embodiment 1 of the present invention;

[0033] Figure 2 A schematic diagram illustrating the principle of grating micro-pits controlling structural color;

[0034] Figure 3 This is a local three-dimensional topographic image of the grating micro-pit array;

[0035] Figure 4 This is a partial profile of the XOZ section of the grating micro-pit array;

[0036] Figure 5 This is a schematic diagram of nanograting diffraction.

[0037] Figure 6 This is a schematic diagram of the image processing path under the line-by-line processing strategy;

[0038] Figure 7 This is a flowchart of the structural color image replication process in Embodiment 2 of the present invention;

[0039] Figure 8 These are fabrication morphology diagrams of cosine micro-pit arrays with different aspect ratios in Embodiment 3 of the present invention;

[0040] Figure 9 This is the color wheel diagram corresponding to the cosine micro-pit arrays with different aspect ratios in Embodiment 3 of the present invention;

[0041] Figure 10 This is a schematic diagram of the hue matrix, saturation matrix, and brightness matrix in Embodiment 4 of the present invention;

[0042] Figure 11 This is a schematic diagram of the SV matrix corresponding to different weight values ​​in Embodiment 4 of the present invention;

[0043] Figure 12 This is a schematic diagram of the nanograting spacing matrix and the micro-pit depth-to-width ratio matrix in Embodiment 4 of the present invention;

[0044] Figure 13 This is a schematic diagram of the nominal cutting speed matrix and the workpiece vibration regulation matrix in Embodiment 4 of the present invention;

[0045] Figure 14 This is a comparison of the structural color images of the surface of the pitless grating structure and the surface of the grating with micro-pits in Embodiment 3 of the present invention. Detailed Implementation

[0046] The embodiments of the present invention are described in detail below:

[0047] Example 1

[0048] Embodiment 1 of the present invention provides a method for replicating high-definition structural color images based on cross-scale structures, comprising the following steps:

[0049] Step S100: Mesh the original image pixels to obtain a pixel matrix composed of multiple pixel units distributed along the nominal cutting direction X and the feed direction Y, and extract the hue matrix H, saturation matrix S and brightness matrix V from the pixel matrix.

[0050] Step S200: Use an ultrasonic elliptical vibrating cutter to perform row-by-row cutting on the surface of the workpiece. After each row of pixel units is cut and processed along the X direction, the ultrasonic elliptical vibrating cutter advances along the Y direction by the distance of one pixel unit and continues to cut and process the next row of pixel units until all pixel units in the pixel matrix of step S100 are cut and processed to obtain a replica image.

[0051] In the process of row-by-row cutting, the ultrasonic elliptical vibrating tool is provided with elliptical vibration of the XOZ plane to cut and process a nano-grating array on the workpiece surface, and the workpiece is provided with cosine vibration of the XOZ plane to cut and process a micro-pit array on the workpiece surface. The grating micro-pit array formed by the superposition of the nano-grating array and the micro-pit array can present a replicated image.

[0052] In this context, the Z direction is the cutting depth direction, and each pixel unit of the pixel matrix corresponds to a grating micro-pit. A grating micro-pit is formed by superimposing a nano grating array and a micro-pit with a cosine profile XOZ cross section. The length of each micro-pit is equal to the pixel size of the corresponding pixel unit along the X direction.

[0053] In the process of line-by-line cutting, the cutting process parameters of the ultrasonic elliptical vibrating tool in step S200 are adjusted according to the hue matrix H, and the vibration trajectory of the workpiece in step S200 is adjusted according to the saturation matrix S and the brightness matrix V.

[0054] An original image can be considered as being composed of several pixels. The color of each pixel can be described using the HSV (Hue-Saturation-Luminosity) three-dimensional color space. Therefore, in step S100, image processing software can be used to mesh the pixels of the original image along the nominal cutting direction X and the feed direction Y to obtain a pixel matrix composed of multiple pixel units. In the pixel matrix, the pixel units are distributed with rows in the X direction and columns in the Y direction. The hue matrix H, saturation matrix S, and luminosity matrix V can be extracted from the pixel matrix using image processing software.

[0055] like Figure 2As shown, in the progressive cutting process, the X direction is the nominal cutting direction, the Y direction is the transverse feed direction, and the Z direction is the depth of cut direction. This method uses an ultrasonic elliptical vibrating tool to perform progressive cutting on the workpiece surface. During cutting, the ultrasonic elliptical vibrating tool is provided with elliptical vibration in the XOZ plane to machine a nano-grating array on the workpiece surface, and the workpiece is provided with cosine vibration in the XOZ plane to machine a micro-pit array on the workpiece surface. Through the vibration of the ultrasonic elliptical vibrating tool and the vibration of the workpiece, a grating micro-pit array can be machined on the workpiece surface. This grating micro-pit array is composed of the aforementioned nano-grating array and micro-pit array superimposed. The local three-dimensional morphology of this grating micro-pit array is shown in the figure. Figure 3 As shown, the local contour of the XOZ section is as follows: Figure 4 As shown, where l cos Let h be the length of the micro-pit, and the length and width of the micro-pit are equal. cos Let S be the depth of the microcrater. The ratio of the length to the width of the microcrater along the X direction is the aspect ratio of the microcrater. nm The grating spacing of the nanograting array is shown below. The XOZ cross-sectional profile of the nanograting structure is similar to a triangle. A schematic diagram of nanograting diffraction is shown below. Figure 5 As shown, θ1 is the incident angle of white light and θ2 is the observation angle. Based on the diffraction effect, the nanograting array can present a specific color that changes with the observer's observation angle.

[0056] like Figure 4 As shown, a grating micro-pit is formed by the superposition of a nanograting array and a micro-pit with a cosine XOZ cross-sectional profile. Figure 2 and Figure 4 As shown, one grating micro-pit corresponds to one pixel unit in the pixel matrix. That is, during machining along the nominal cutting direction X, machining one grating micro-pit completes the machining of one pixel unit, and machining one row of grating micro-pits completes the machining of one row of pixel units. Figure 6 As shown, after machining one row of pixel units, the tool retracts and then feeds forward the distance of one pixel unit along the Y direction to continue machining the next row of pixel units, until all pixel units are machined. Since one grating micro-pit corresponds to one pixel unit, the length of each micro-pit is equal to the pixel size of the corresponding pixel unit along the X direction.

[0057] In this method, the processed image is presented by a grating micro-pit array. Through the complex optical interactions between the nano-grating array and the micro-pit array, richer colors can be presented. Figure 2As shown, by assigning different cutting process parameters to the tool and the workpiece, pixel units with different hues, saturations, and brightness can be machined. Therefore, during the machining process, the cutting process parameters of the ultrasonic elliptical vibrating tool can be adjusted according to the hue of the original image, and the vibration trajectory of the workpiece can be adjusted according to the saturation and brightness of the original image. This allows for the adjustment of the grating spacing of the nano-grating array and the aspect ratio of the micro-pit cross-section profile, thereby achieving two-dimensional control of structural color by the grating micro-pit array feature structure. This results in a more colorful image on the structured surface and more accurately replicates the required high-definition structural color image.

[0058] Example 2

[0059] Reference Figure 7 Embodiment 2 of the present invention provides a method for replicating high-definition structural color images based on cross-scale structures. An ultrasonic elliptical vibrating tool is used to perform line-by-line cutting on the workpiece surface. During cutting, the ultrasonic elliptical vibrating tool is provided with elliptical vibration in the XOZ plane to cut a nano-grating array on the workpiece surface, and cosine vibration in the XOZ plane is provided to the workpiece to cut a micro-pit array on the workpiece surface. Here, the X direction is the nominal cutting direction, the Y direction is the feed direction, and the Z direction is the depth of cut direction. This replication method includes the following steps:

[0060] Step S100: Mesh the original image pixels to obtain a pixel matrix composed of multiple pixel units distributed along the nominal cutting direction X and the feed direction Y. Extract the tone matrix H(X) from the pixel matrix. n ,Y n ), Saturation matrix S(X) n ,Y n ) and brightness matrix V(X) n ,Y n The cutting process parameters of the ultrasonic elliptical vibration tool are adjusted through the following steps:

[0061] Step S110: During image processing, the hue value H, saturation value S, and brightness value V can all be normalized to values ​​between 0 and 1. Therefore, the hue value H is converted into the wavelength λ of the structural color using the following formula (1):

[0062]

[0063] Step S120: Convert the light wavelength λ into the grating spacing S of the nanograting array using the following formula (2). nm :

[0064]

[0065] Where N is the diffraction order, θ1 is the incident angle of white light, and θ2 is the observation angle. After determining the incident angle θ1, the observation angle θ2, and the diffraction order N, the grating spacing matrix S can be solved according to the above formula (2) and the light wavelength λ determined in step S110. nm (X n ,Y n );

[0066] Step S130: Select the vibration frequency f of the ultrasonic elliptical vibrating tool. e And through the grating spacing S determined in step S120 nm The nominal cutting speed v of the ultrasonic elliptical vibrating tool is determined by the following formula (3):

[0067] S nm =v / f e (3)

[0068] The cosine vibration trajectory of the workpiece can be controlled by the following steps:

[0069] Step S140: When increasing the control dimension of structural color by adjusting the aspect ratio of micropits, the aspect ratio can be determined by the saturation and brightness of the color. The saturation S and brightness V can be converted into parameter SV using the following formula (4):

[0070] SV=a×S+(1-a)×V⑷;

[0071] Where a is the weight of saturation, ranging from 0 to 1, then (1-a) is the weight of brightness. When a is 0, SV is brightness V, and when a is 1, SV is saturation S. The larger the value of SV, the stronger the spectrum of the surface structural color.

[0072] Step S150: Determine the depth-to-width ratio A of the micro-pit using the following formula (5). r :

[0073] A r = (1-SV)×A max (5)

[0074] Among them, A max The maximum aspect ratio of the micro-pit can be adjusted according to processing requirements;

[0075] Step S160: Based on the pixel size p of the pixel unit along the X direction L Determine the length l of the micropit cos The depth h of the micro-pit is determined by the following formula (6). cos :

[0076] A r =h cos / l cos (6)

[0077] Step S170: Obtain the vibration trajectory of the workpiece using the following formula (7):

[0078]

[0079] The nominal cutting speed v and vibration frequency f of the ultrasonic elliptical vibrating tool were determined through the above steps. e After determining the cosine vibration trajectory of the workpiece, the X and Z axis amplitudes and phase differences of the ultrasonic elliptical vibration, as well as the tool tip radius R, are then used according to the machining requirements. n Minimum cutting depth D min With these parameters, the image can be replicated by following these steps based on the process parameters:

[0080] Step S200: An ultrasonic elliptical vibrating cutter with an ultrasonic elliptical vibration trajectory performs cutting on the workpiece surface along the nominal cutting direction X at the nominal cutting speed v determined above. Simultaneously, the workpiece vibrates according to the determined vibration trajectory. After each row of pixel units is machined along the X direction, the ultrasonic elliptical vibrating cutter advances one pixel unit distance along the Y direction and continues machining the next row of pixel units until all pixel units are machined, obtaining the final replicated image. Each pixel of the replicated image is composed of a single grating micro-pit; therefore, the length l of the micro-pit... cos Equal to the size p of the pixel along the X direction L Because a line-by-line processing method is used, each line of contour processed by the cutting tool produces a line of pixels for the replicated image.

[0081] This method allows adjustment of the grating spacing S by changing the nominal cutting speed v. nm The aspect ratio A of the micro-pit cross-section profile is adjusted by changing the vibration trajectory of the workpiece. r This method enables two-dimensional control of structural color by the grating micro-pit feature structure, allowing the hue, saturation, and brightness of the replicated image to better match the original image, achieving more accurate replication of high-definition structural color images. The structural color of the processed image is presented by the grating micro-pit array on the workpiece surface, which is composed of a superposition of a nano-grating array and a micro-pit array. The XOZ cross-section of the micro-pit has a cosine profile, while the XOZ cross-section profile of the nano-grating structure has a triangular-like profile. In this method, the grating spacing S is mainly adjusted by changing the nominal cutting speed v. nm The height of the grating can be selected according to actual processing requirements, as long as the grating has sufficient height. The XOZ cross-sectional profile equation of the micro-pit is determined by the aforementioned method, while the YOZ cross-sectional profile is directly determined by the shape of the tool tip.

[0082] Example 3

[0083] Reference Figure 8 To demonstrate that adding a micro-pit array to the surface feature structure can increase color richness and facilitate a clear assessment of the micro-pit's regulation of light intensity, this study aims to achieve two-dimensional control of structural color by adjusting the grating spacing of the nanograting array and the aspect ratio of the micro-pit cross-section. In this embodiment, six sets of grating micro-pit arrays with different aspect ratios were designed for processing. In each of the six sets, the width of a single cosine micro-pit is the same (0.2mm × 0.2mm), while the aspect ratios (depths) of the cosine micro-pits differ, meaning their depths vary. The grating spacing of the nanogratings is essentially the same, and the diamond tool used has a tip radius of 1mm. During processing, the amplitude and phase difference in the X and Y directions of the ultrasonic elliptical vibration trajectory of the tool tip are 1μm, 2.5μm, and -π / 2, respectively, with a vibration frequency of f. e =40kHz. The vibration trajectory of the workpiece is determined by the XOZ cross-sectional profile of the cosine micro-pit array.

[0084] The fabrication morphology of the six sets of grating micro-pits is as follows: Figure 8 As shown, in Figure 8 In the image, the aspect ratios corresponding to the morphologies of parts a, b, c, d, e, and f are 0%, 0.75%, 1.25%, 1.9%, 2.5%, and 3.3%, respectively. Under the same light incident angle, the similar spacing between the nanogratings results in similar hues of the structural colors in each group of grating micro-pit arrays. With the observation angle fixed at 0°, the incident angle of the parallel light was adjusted, and color images of each group of grating micro-pit arrays were captured using a mobile phone. These color images were then stitched together to create an effect similar to a color wheel, as shown in the image. Figure 9 As shown, for the same group of grating micro-pit arrays, the color of the color patch changes significantly with the change of the incident angle. When the incident angle is fixed, the color also changes significantly with the change of the aspect ratio of the micro-pit. These effects demonstrate the two-dimensional control capability of the grating micro-pit feature structure on the structural color.

[0085] Example 4

[0086] Embodiment four of the present invention provides a specific process for replicating high-definition images. Using the replication method in Embodiment two, Van Gogh's famous painting "The Starry Night" is processed. This image has dimensions of 120 pixels in length × 90 pixels in width. Image processing software is used to extract the hue, saturation, and brightness matrices of this image, wherein the hue matrix, saturation matrix, and brightness matrix are respectively as shown below. Figure 10Parts a, b, and c are shown in the diagram. It can be seen from the tone matrix H that many local areas of this image have relatively small tone differences. When only a nanograting structure is used to replicate the image, the contour details of the structural color image are not rich enough. Therefore, the replication method in Example 2 is used, adding a cosine micro-pit structure for replication. In this example, the amplitude and phase difference in the X and Y directions of the ultrasonic elliptical vibration trajectory of the blade tip are 1 μm, 2.5 μm, and -π / 2, respectively, and the vibration frequency is f. e =40kHz. Individual pixel size is p L =0.2mm, then the dimensions of the structural color image are 24mm long × 19.4mm wide. The maximum aspect ratio of the cosine micropit is taken as A. max =0.04. Furthermore, the incident angle θ1, observation angle θ2, and diffraction order N are 45°, 0, and 1, respectively.

[0087] Regarding the selection of 'a', we can consider the impact of different values ​​of weight 'a' on the SV matrix. When 'a' = 1, the SV matrix is ​​the saturation matrix S, and when 'a' = 0, the SV matrix is ​​the brightness matrix V. Figure 11 Parts a, b, and c show the SV matrices for a = 0.75, a = 0.5, and a = 0.25, respectively. From the three SV matrices, it can be seen that the contours of the micro-pit array will differ significantly when a takes different values. Therefore, the introduction of a also increases the flexibility of color control during structural color image replication. In this embodiment, taking a = 0.5 as an example, the process parameters for target image replication are demonstrated.

[0088] Through the replication steps in Example 2, the extracted hue matrix, saturation matrix, and brightness matrix are as follows: Figure 10 As shown in parts a, b, and c, the obtained nanograting spacing matrix and micro-pit aspect ratio matrix are as follows: Figure 12 As shown in parts a and b, the nominal cutting speed matrix and the workpiece vibration regulation matrix are as follows: Figure 13 Parts a and b are shown in the diagram. To further demonstrate the feasibility and advantages of the image replication method for controlling the micro-pit structure of the grating, structural color images were replicated according to the above process parameters. First, the tool tip vibrates while the workpiece remains still, creating a micro-pit-free nano-grating structure surface. Second, the micro-pit structure surface of the grating is created by vibrating both the tool tip and the workpiece. An LED white light was used as the light source with an incident angle of 45°, and a regular mobile phone camera was used for photography with a shooting angle of 0°.

[0089] Depend on Figure 14 A comparison of the structural color images of the surface of the pitless nanograting structure and the surface of the grating with micro-pits can be seen. Figure 14 Parts a and b in the diagram correspond to the structure color images of the surface of the pitless nanograting structure and the structure color image of the surface of the grating with micro-pits, respectively. Figure 14It can be seen that although there is an error between the actual trajectory of the tool tip relative to the workpiece and the ideal trajectory, and an error between the incident angle and the designed incident angle and the observation angle during shooting, resulting in a certain difference in color between the structural color image of the completed workpiece and the original image, through... Figure 14 It can still be seen that the surface of the nano-grating structure without micro-pits can only display the general outline of the original image, but the details are relatively blurry. This is because the grating structure surface can only control the color tone of the image, and the color tones of pixels in many local areas of the original image are quite similar. In contrast, the structural color image presented by the grating micro-pit structure surface has richer details and colors, and the displayed image is closer to the original image. This verifies that the grating micro-pit structure surface has a stronger and more flexible control over structural colors, and also verifies the feasibility and excellence of this image replication method.

[0090] It should be noted that in the description of this invention, any descriptions of orientation, such as up, down, front, back, left, right, etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of this invention.

[0091] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, while "above," "below," "within," etc. are understood to include the stated number. If "first" or "second" is mentioned, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0092] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0093] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for replicating a high-definition structural color image based on a cross-scale structure, characterized in that, Includes the following steps: Step S100: Mesh the original image pixels to obtain a pixel matrix composed of multiple pixel units distributed along the nominal cutting direction X and the feed direction Y, and extract the tone matrix from the pixel matrix. H ( X n , Y n ), saturation matrix S ( X n , Y n ) and brightness matrix V ( X n , Y n ); Step S200: Use an ultrasonic elliptical vibrating cutter to perform row-by-row cutting on the surface of the workpiece. After each row of pixel units is cut and processed along the X direction, the ultrasonic elliptical vibrating cutter advances along the Y direction by the distance of one pixel unit and continues to cut and process the next row of pixel units until all pixel units in the pixel matrix of step S100 are cut and processed to obtain a replica image. In the process of row-by-row cutting, the ultrasonic elliptical vibrating tool is provided with elliptical vibration of the XOZ plane to cut and process a nano-grating array on the workpiece surface, and the workpiece is provided with cosine vibration of the XOZ plane to cut and process a micro-pit array on the workpiece surface. The grating micro-pit array formed by the superposition of the nano-grating array and the micro-pit array can present a replicated image. In this context, the Z direction is the cutting depth direction, and each pixel unit of the pixel matrix corresponds to a grating micro-pit. A grating micro-pit is formed by superimposing a nano grating array and a micro-pit with a cosine profile XOZ cross section. The length of each micro-pit is equal to the pixel size of the corresponding pixel unit along the X direction. In the process of line-by-line cutting, according to the color matrix H ( X n , Y n The cutting process parameters of the ultrasonic elliptical vibration tool in step S200 are adjusted according to the saturation matrix. S ( X n , Y n ) and brightness matrix V ( X n , Y n The vibration trajectory of the workpiece in step S200 is controlled.

2. The method for replicating high-definition structural color images based on cross-scale structures according to claim 1, characterized in that, The cutting process parameters of the ultrasonic elliptical vibration tool are adjusted through the following steps: Step S110: Set the hue value H The light wavelength is converted into structural color using the following formula (1). λ : ⑴； Step S120: Adjust the light wavelength λ The grating spacing of the nanograting array is converted using the following formula (2). S nm : ⑵； in, N The diffraction order is... θ 1 is the angle of incidence of white light. θ 2 is the observation angle; Step S130: Select the vibration frequency of the ultrasonic elliptical vibrating tool. f e The nominal cutting speed of the ultrasonic elliptical vibrating tool is determined by the following formula (3). v : ⑶。 3. The method for replicating high-definition structural color images based on cross-scale structures according to claim 1 or 2, characterized in that, The vibration trajectory of the workpiece can be controlled by the following steps: Step S140: Set the saturation value S and brightness value V Convert to parameters using the following formula (4) SV : ⑷； in, a The weight for saturation ranges from 0 to 1; Step S150: Determine the depth-to-width ratio of the micropit using the following formula (5). A r : ⑸； in, A max This represents the maximum aspect ratio of the micro-pit; Step S160: Based on the pixel size of the pixel unit along the X direction p L Determine the length of the micropit l cos The depth of the micro-pit is determined by the following formula (6). h cos : ⑹； Step S170: Obtain the vibration trajectory of the workpiece using the following formula (7): ⑺。

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