Image processing method and device for surface projection 3D printing and storage medium

Abstract

The invention discloses an image processing method and device for surface projection 3D printing and a storage medium. The method comprises the steps that a slice image for surface projection 3D printing is acquired; parameters of a first image area in the slice image are adjusted to obtain a target image, and compared with the mode that the first image area before parameter adjustment is projected to a photocuring area during surface projection 3D printing, the photocuring degree of the photocuring area where the first image area after parameter adjustment is projected during surface projection 3D printing is reduced. In this way, the photocuring degree of the photocuring area can be reduced.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, and in particular, to an image processing method for surface projection 3D printing, an image processing device for surface projection 3D printing, and a storage medium. Background Art

[0002] The sliced images obtained after slicing a three-dimensional model for surface projection 3D printing are directly used for surface projection 3D printing, and the resulting finished products may have over-curing situations, such as: the finished products are deformed, and the holes in the finished products are blocked, etc. Summary of the Invention

[0003] Based on this, this application provides an image processing method for surface projection 3D printing, an image processing device for surface projection 3D printing, and a storage medium, which can reduce the degree of photocuring in the photocuring area, thereby reducing the impact of over-curing on the area around the photocuring area.

[0004] In a first aspect, this application provides an image processing method for surface projection 3D printing, and the method includes:

[0005] Obtain a sliced image for surface projection 3D printing;

[0006] Adjust the parameters of the first image area in the sliced image to obtain a target image. Compared with the first image area before parameter adjustment, when projected onto the photocuring area during surface projection 3D printing, the degree of photocuring of the first image area after parameter adjustment projected onto the photocuring area during the surface projection 3D printing is reduced.

[0007] In a second aspect, this application provides an image processing device for surface projection 3D printing. The image processing device includes a processor and a memory. The memory is further configured to store a computer program. The processor is configured to execute the computer program and, when executing the computer program, implement the above-mentioned image processing method for surface projection 3D printing.

[0008] In a third aspect, this application provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor is caused to implement the above-mentioned image processing method for surface projection 3D printing.

[0009] After obtaining a sliced image for surface projection 3D printing in an embodiment of the present application, parameters of a first image region in the sliced image are adjusted to obtain a target image. The target image includes the first image region with adjusted parameters. Compared with the first image region before parameter adjustment, when projected onto a photocuring region during surface projection 3D printing, the photocuring degree of the photocuring region onto which the first image region with adjusted parameters is projected during the surface projection 3D printing is reduced; since the sliced image is not directly used for 3D printing, but the sliced image is processed to obtain a target image, that is, parameters of the first image region are adjusted to obtain the target image, and the processed target image is used for 3D printing, the photocuring degree of the photocuring region onto which the first image region is projected can be reduced. Therefore, in this way, problems such as finished product deformation caused by over-curing around the photocuring region and blockage of holes in the finished product can be minimized as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic flowchart of an embodiment of an image processing method for surface projection 3D printing according to the present application;

[0011] Figure 2 is a schematic flowchart of another embodiment of an image processing method for surface projection 3D printing according to the present application;

[0012] Figure 3 is a schematic flowchart of yet another embodiment of an image processing method for surface projection 3D printing according to the present application;

[0013] Figure 4 is a schematic flowchart of yet another embodiment of an image processing method for surface projection 3D printing according to the present application;

[0014] Figure 5 is an image before gray filling and a target image after gray filling in an embodiment of an image processing method for surface projection 3D printing according to the present application;

[0015] Figure 6 is Figure 5 a local original image and a local binarized image in an embodiment of

[0016] Figure 7 is Figure 5 a hole region in an embodiment of

[0017] Figure 8 is Figure 5 a first edge sub-image region in an embodiment of

[0018] Figure 9 is Figure 5 a second edge sub-image region in an embodiment of

[0019] Figure 10 isFigure 5 The internal sub-image area after filling grayscale in the embodiment of

[0020] Figure 11 is Figure 5 the target image in the embodiment of

[0021] Figure 12 the image before grayscale filling and the target image after grayscale filling in another embodiment of the image processing method for surface projection 3D printing of the present application;

[0022] Figure 13 is Figure 12 the hole area in the embodiment of

[0023] Figure 14 is Figure 12 the hole area after filling grayscale in the embodiment of

[0024] Figure 15 is Figure 12 the target image in the embodiment of

[0025] Figure 16 the image before grayscale filling and the target image after grayscale filling in yet another embodiment of the image processing method for surface projection 3D printing of the present application. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0027] The flowchart shown in the accompanying drawings is only an example illustration, and does not necessarily include all the contents and operations / steps, nor does it necessarily need to be executed in the described order. For example, some operations / steps can also be decomposed, combined, or partially merged. Therefore, the actual execution order may be changed according to the actual situation.

[0028] The sliced image obtained after slicing the 3D model for surface projection 3D printing is directly used for surface projection 3D printing, and the resulting finished product will have the situation of over-curing. For example, the finished product is deformed, and the holes in the finished product are blocked, etc.

[0029] In the embodiment of the present application, after acquiring a slice image for surface projection 3D printing, the parameters of the first image area in the slice image are adjusted to obtain a target image, wherein the target image includes the first image area after the parameters are adjusted, and compared with the first image area before the parameters are adjusted when projected onto the photocuring area during surface projection 3D printing, the photocuring degree of the photocuring area projected onto the first image area after the parameters are adjusted during surface projection 3D printing is reduced; since the slice image is not directly 3D printed, but the slice image is processed to obtain the target image, that is, the parameters of the first image area are adjusted to obtain the target image, 3D printing is performed using the processed target image, which can reduce the photocuring degree of the photocuring area onto which the first image area is projected. Therefore, in this way, problems such as deformation of the finished product and blockage of holes in the finished product caused by over-curing around the photocuring area can be minimized.

[0030] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0031] See also Figure 1 , Figure 1 It is a flowchart of an embodiment of an image processing method for surface projection 3D printing of the present application, and the method includes: step S101 and step S102.

[0032] Step S101: Acquire a slice image for surface projection 3D printing.

[0033] Step S102: Adjust the parameters of the first image area in the slice image to obtain a target image. Compared with the first image area before the parameters are adjusted and projected onto the photocuring area during surface projection 3D printing, the photocuring degree of the first image area after the parameters are adjusted and projected onto the photocuring area during surface projection 3D printing is reduced.

[0034] In the embodiment of the present application, the slice image may be an original slice image after slicing the three-dimensional model for surface projection 3D printing, or may be a slice image after preprocessing (other processing except adjusting parameters) the original slice image, for example, the preprocessing includes grayscale processing, or grayscale processing and binarization processing, etc. The photocuring area may refer to an area that needs to be photocured.

[0035] In the embodiments of the present application, the parameter may refer to a parameter that affects the degree of photocuring of the photocuring area projected by the first image area. For example: The parameter may be the light intensity of the light source corresponding to the pixels in the first image area when projecting the first image area. Image recognition can be performed first. After recognizing the first image area, the light intensity of the light source corresponding to the pixels in the first image area can be decreased. After the light intensity of the light source decreases, the degree of photocuring of the photocuring area projected by the first image area will decrease. Another example: The parameter may be the gray value of the pixels in the first image area. In some surface projection 3D printing, the sliced images used include binary sliced images. In the binary sliced images, the white image areas will reflect light, and the reflected light will irradiate the photocuring area (i.e., the area that needs to be photocured). The black image areas in the binary sliced images will not reflect light. Therefore, the black image areas are projected onto the non-photocuring area (i.e., the area that does not need to be photocured). At this time, the gray value of the pixels in the white image areas in the binary sliced images can be adjusted to a gray gray value. In this way, the adjusted gray image areas will also reflect light, but the intensity of the reflected light will decrease. Therefore, after the reflected light with reduced intensity irradiates the photocuring area (i.e., the area that needs to be photocured), the degree of photocuring will decrease.

[0036] There are generally two reasons for over-curing of the product: One reason is that, for example, there are small holes in a 3D model. The holes are empty, and the image will be represented by a black circle. The area around the hole is white. Since light is prone to scattering and there may be light leakage during actual light machine exposure, the black circle representing the hole will not be completely without light during actual exposure, and there will be a small amount of stray light superimposed at the position of the black circle, resulting in a small amount of gray scale at the black-and-white boundary. Another reason is that the photosensitive resin being irradiated is liquid, and the liquid photosensitive resin is constantly moving. The photocuring process relies on free radicals. Therefore, free radicals in the photosensitive resin projected by the irradiated white area in the image will diffuse into the photosensitive resin projected by the non-irradiated black area, thereby causing the photosensitive resin projected by the black area to undergo a photocuring reaction (the photosensitive resin projected by the black area should not undergo a photocuring reaction). The result of these two reasons is that the photosensitive resin projected by the black area, which should not be cured, has undergone curing. Therefore, this situation is called over-curing of the product.

[0037] After acquiring a slice image for surface projection 3D printing, the embodiment of the present application adjusts the parameters of the first image area in the slice image to obtain a target image, wherein the target image includes the first image area after the parameters are adjusted, and the first image area before the parameters are adjusted is projected onto the photocuring area during surface projection 3D printing, and the photocuring degree of the photocuring area projected onto the first image area after the parameters are adjusted during the surface projection 3D printing is reduced; since the slice image is not directly 3D printed, but the slice image is processed to obtain the target image, that is, the parameters of the first image area are adjusted to obtain the target image, 3D printing is performed using the processed target image, which can reduce the photocuring degree of the photocuring area onto which the first image area is projected; because the photocuring degree of the photocuring area onto which the first image area is projected is reduced, when the first image area is projected onto the photocuring area, its influence on the over-curing of the surrounding non-photocuring areas will be reduced, and therefore, in this way, problems such as deformation of the finished product and blockage of holes in the finished product caused by over-curing around the photocuring area can be minimized.

[0038] In some embodiments, step S102, adjusting the parameters of the first image area in the slice image to obtain the target image may include: adjusting the parameters of the internal sub-image area of ​​the first image area, and keeping the parameters of the edge sub-image area of ​​the first image area unchanged, thereby obtaining the target image.

[0039] In the embodiment of the present application, the first image area is divided into an internal sub-image area and an edge sub-image area. When adjusting the parameters, the parameters of the internal sub-image area are adjusted, and the parameters of the edge sub-image area are kept unchanged. In this way, on the one hand, the degree of photocuring of the internal sub-curing area of ​​the photocuring area projected onto the internal sub-image area is reduced, which can reduce the problems caused by over-curing around the photocuring area. On the other hand, it helps to maintain the shape of the edge sub-curing area located at the edge of the photocuring area, avoiding the situation where the shape of the edge sub-curing area located at the edge of the photocuring area cannot be maintained or cannot be well maintained due to the reduction in the degree of photocuring.

[0040] In some embodiments, the slice image is obtained based on the unshelled three-dimensional model, and the first image area includes a solid image area. In the embodiment of the present application, the unshelled three-dimensional model is sliced ​​to obtain the slice image, so the first image area includes the corresponding solid image area.

[0041] At this time, step S102, adjusting the parameters of the inner sub-image area of ​​the first image area and keeping the parameters of the edge sub-image area of ​​the first image area unchanged, thereby obtaining the target image, may also include sub-steps S102A1, S102A2 and S102A3, such as Figure 2 shown.

[0042] Sub-step S102A1: respectively determine the edge sub-image region of the entity image region and the internal sub-image region of the entity image region according to the slice image.

[0043] Sub-step S102A2: adjust the parameters of the internal sub-image region of the entity image region according to preset requirements to obtain the internal sub-image region of the entity image region with adjusted parameters.

[0044] Sub-step S102A3: add the internal sub-image region of the entity image region with adjusted parameters and the edge sub-image region of the unadjusted entity image region to obtain the target image.

[0045] In the embodiment of the present application, the preset requirements may refer to the specific requirements for adjusting the parameters of the internal sub-image region of the first image region (such as the entity image region) so as to reduce the photocuring degree of the internal sub-curing region of the photocuring region projected by the internal sub-image region; the preset requirements can be set according to the needs of the user. It should be noted that adjusting the parameters of the internal sub-image region does not mean that the adjusted parameters of the internal sub-image region are all the same. The adjusted parameters of the internal sub-image region can have two or more different adjusted parameters. For example, the internal sub-image region can be further divided into multiple sub-regions, and the adjusted parameters of the multiple sub-regions are different from each other.

[0046] In order to meet the requirement of adjusting the parameters of the internal sub-image region while keeping the parameters of the edge sub-image region unchanged when adjusting the parameters, for the entity image region, it is first necessary to determine the edge sub-image region of the entity image region and the internal sub-image region of the entity image region, and then the parameters of the edge sub-image region of the entity image region can be adjusted while keeping the parameters of the internal sub-image region of the entity image region unchanged when adjusting the parameters.

[0047] There are many specific ways to respectively determine the edge sub-image region of the entity image region and the internal sub-image region of the entity image region according to the slice image. It can adopt a rough method or a fine method. For example, the rough method can be to set the width of the edge sub-image region according to actual needs, and accordingly divide the edge sub-image region of the entity image region and the internal sub-image region of the entity image region; etc.

[0048] In some embodiments, if the sliced image further includes a hole image region and the hole image region is surrounded by the entity image region, it is also necessary to determine the first edge sub-image region of the entity image region located around the hole image region, because the first edge sub-image region located around the hole image region is also part of the edge sub-image region of the entity image region. Therefore, in sub-step S102A1, the step of respectively determining the edge sub-image region of the entity image region and the internal sub-image region of the entity image region according to the sliced image may further include: when the sliced image further includes a hole image region and the hole image region is surrounded by the entity image region, respectively determining, according to the sliced image, the first edge sub-image region of the entity image region located around the hole image region, the second edge sub-image region of the entity image region except the first edge sub-image region, and the internal sub-image region of the entity image region.

[0049] At this time, in sub-step S102A3, the step of adding the internal sub-image region of the entity image region after adjusting the parameters and the edge sub-image region of the unadjusted entity image region to obtain the target image may further include: adding the first edge sub-image region of the unadjusted entity image region, the internal sub-image region of the entity image region after adjusting the parameters, and the second edge sub-image region of the unadjusted entity image region to obtain the target image.

[0050] In some embodiments, some image processing methods (such as dilation processing, erosion processing, image arithmetic processing, etc.) can be used to precisely determine the first edge sub-image region, the second edge sub-image region, and the internal sub-image region.

[0051] For example, in some embodiments, in sub-step S102A1, the step of respectively determining, according to the sliced image, the first edge sub-image region of the entity image region located around the hole image region, the second edge sub-image region of the entity image region except the first edge sub-image region, and the internal sub-image region of the entity image region may further include: sub-steps S102A11 to S102A13, as Figure 3 shown.

[0052] Sub-step S102A11: Perform dilation processing on the hole image region in the sliced image, subtract the hole image region after dilation from the hole image region before dilation to obtain the outer ring image region around the hole image region, and perform an AND operation on the outer ring image region and the sliced image to obtain the first edge sub-image region of the entity image region that is consistent with the edge shape of the hole image region.

[0053] The dilation of an image refers to adding pixel values to the edges of the image, causing the overall pixel values to expand, thereby achieving the dilation effect of the image. It is mainly used to find the maximum regions in the image, similar to "neighborhood expansion". The highlighted regions or white parts in the image are expanded, and the resulting image has a larger highlighted region than the original image. The AND operation is a basic logical operation method in a computer, denoted by the symbol "&", and its operation rules are: 0&0 = 0, 0&1 = 0, 1&0 = 0, 1&1 = 1. The AND operation of an image means performing a binary "AND" operation on each pixel value of two images (both grayscale images or color images are acceptable) to achieve image clipping. Therefore, by performing an AND operation on the outer ring image region and the slice image, a first edge sub-image region of the entity image region that is consistent with the edge shape of the hole image region can be obtained.

[0054] Sub-step S102A12: Fill the hole image region in the slice image and erode the entity image region. After subtracting the eroded entity image region from the entity image region before erosion and performing an AND operation with the slice image, a second edge sub-image region of the entity image region that is consistent with the edge shape of the entity image region is obtained.

[0055] The erosion of an image can be used to eliminate the boundary points of an object, causing the boundary to shrink inward. Objects smaller than the structuring element can be removed, so it can be used to remove burrs, small protrusions, etc. Erosion is similar to "neighborhood being eaten away". The highlighted regions or white parts in the image are reduced and refined, and the resulting image has a smaller highlighted region than the original image. Therefore, after subtracting the eroded entity image region from the entity image region before erosion and performing an AND operation with the slice image, a second edge sub-image region of the entity image region that is consistent with the edge shape of the entity image region can be obtained.

[0056] It should be noted that there is no obvious sequential relationship between the above sub-step S102A11 and sub-step S102A12. They can be performed simultaneously, or sub-step S102A12 can be executed first and then sub-step S102A11.

[0057] Sub-step S102A13: Subtract the first edge sub-image region of the entity image region and the second edge sub-image region of the entity image region from the slice image respectively to obtain the internal sub-image region of the entity image region.

[0058] When the first edge sub-image region of the entity image region and the second edge sub-image region of the entity image region are determined, the internal sub-image region of the entity image region can be obtained by subtracting the first edge sub-image region of the entity image region and the second edge sub-image region of the entity image region from the slice image respectively.

[0059] In some embodiments, the slice image is obtained from a shelled three-dimensional model. The first image region includes a closed shelled image region, and the closed shelled image region includes an internal shelled image sub-region and a shell image sub-region with a closed edge. In the embodiments of the present application, the shelled three-dimensional model is sliced to obtain the slice image. Therefore, the first image region includes a closed shelled image region. Since the closed shelled image region is clearly divided into a shelled image sub-region and a shell image sub-region surrounding the edge of the shelled image sub-region, it is not necessary to distinguish the shelled image sub-region and the shell image sub-region first, and the parameters of the shelled image region can be directly adjusted. That is, in step S102, the step of adjusting the parameters of the internal sub-image region of the first image region and keeping the parameters of the edge sub-image region of the first image region unchanged to obtain the target image may include sub-step S102B1 and sub-step S102B2, as Figure 4 shown.

[0060] Sub-step S102B1: Adjust the parameters of the shelled image region according to a preset requirement to obtain a shelled image region with adjusted parameters.

[0061] The preset requirement may refer to the specific requirement for adjusting the parameters of the internal sub-image region of the first image region (such as the shelled image sub-region) to reduce the degree of photocuring of the internal sub-curing region of the photocuring region projected by the internal sub-image region. The preset requirement can be set according to the user's needs. It should be noted that adjusting the parameters of the internal sub-image region does not mean that the adjusted parameters of the internal sub-image region are all the same. The adjusted parameters of the internal sub-image region can have two or more different adjusted parameters. For example, the internal sub-image region can be further divided into multiple sub-regions, and the adjusted parameters of the multiple sub-regions are different from each other.

[0062] Sub-step S102B2: Add the shelled image region with adjusted parameters and the shelled image region before parameter adjustment to obtain the target image.

[0063] The shelling image area before adjusting the parameters includes an unadjusted shelling image sub - area and an unadjusted edge - enclosed shell image sub - area. Adding the shelling image area after adjusting the parameters, that is, replacing the unadjusted shelling image sub - area with the shelling image sub - area after adjusting the parameters, so the target image is the shelling image sub - area after adjusting the parameters and the unadjusted edge - enclosed shell image sub - area, ensuring that on the basis of adjusting the parameters of the internal shelling image sub - area, the parameters of the edge - enclosed shell image sub - area remain unchanged.

[0064] Of course, it is also possible to directly adjust the parameters of the shelling image sub - area, and then add the shelling image sub - area after adjusting the parameters to the unadjusted shelling image sub - area, and the target image can also be obtained.

[0065] In some embodiments, the method may further include:

[0066] Step S103: Obtain the first - layer printing format image for surface - projection 3D printing, and adjust the parameters within the area of the first - layer printing format image; compared with the area of the first - layer printing format image before adjusting the parameters projected onto the photocuring area during surface - projection 3D printing, the photocuring degree of the photocuring area onto which the area of the first - layer printing format image after adjusting the parameters is projected during the surface - projection 3D printing is increased.

[0067] In the embodiments of the present application, in order to make the first printing layer fit better with the printing platform, for the first - layer printing format image, the parameters within the area of the first - layer printing format image are adjusted. The photocuring degree of the photocuring area onto which the area of the first - layer printing format image after adjusting the parameters is projected during the surface - projection 3D printing is increased, so that the first printing layer can fit better with the printing platform.

[0068] In some embodiments, the first - layer printing format image includes a first - layer slice image area and other image areas; the other image areas refer to the image areas in the first - layer printing format image except the first - layer slice image area.

[0069] At this time, in step S103, the adjusting the parameters within the area of the first - layer printing format image may include: adjusting the parameters of the other image areas to obtain a target image of the adjusted other image areas; compared with the other image areas before adjusting the parameters projected onto the photocuring area during surface - projection 3D printing, the photocuring degree of the photocuring area onto which the other image areas after adjusting the parameters are projected during the surface - projection 3D printing is increased.

[0070] The other image regions are part of the first-layer printing format image region. In the embodiments of the present application, in order to make the first layer of printing better fit the printing platform, the parameters of a part of the first-layer printing format image region are adjusted, that is, the parameters of the other image regions are adjusted. The photocuring degree of the photocuring region projected by the adjusted other image regions during the surface projection 3D printing is increased. In this way, the fitting degree between the photocuring region projected by the adjusted other image regions in the first layer of printing and the printing platform can be improved.

[0071] In some embodiments, in step S103, the adjusting the parameters within the first-layer printing format image region may further include: adjusting the parameters of the first-layer sliced image region to obtain a target image of the adjusted other region; compared with the photocuring region projected by the first-layer sliced image region before parameter adjustment during the surface projection 3D printing, the photocuring degree of the photocuring region projected by the first-layer sliced image region after parameter adjustment during the surface projection 3D printing is increased.

[0072] In order to make the first layer of printing fit the printing platform even better, the parameters of another part of the first-layer printing format image region may be further adjusted, that is, the parameters of the first-layer sliced image region are adjusted. The photocuring degree of the photocuring region projected by the adjusted first-layer sliced image region during the surface projection 3D printing is increased. In this way, the fitting degree between the photocuring region projected by the adjusted first-layer sliced image region in the first layer of printing and the printing platform can be further improved.

[0073] In some embodiments, the sliced image includes a binary sliced image, and the parameter includes the gray value of the pixel.

[0074] In some embodiments, taking the 3D printing of DLP as an example, the exposure is performed in the form of a projected image; the projected image is black and white, and there is a gray scale at the black and white junction (not very black and not very white); the actual exposure effect is that light is reflected from the white area of the black and white image, while no light is reflected from the black area. Therefore, the black and white image is converted into an exposure pattern; and the ultraviolet light of a certain wavelength emitted by the exposure can cause a chemical reaction of the photosensitive resin, changing from a liquid to a solid (that is, the photosensitive resin irradiated by the light reflected from the white area undergoes a photochemical reaction to become a solid photocuring region). The gray scale is presented in gray; in the white area of the image, the actual exposure brightness is the largest; in the gray area of the image, the exposure brightness changes according to the degree of gray; the whiter the area looks, the brighter the actual exposure, and the black area is not exposed at all; therefore, adjusting the gray value of the pixels in the first image region can reduce the photocuring degree of the photocuring region projected by it.

[0075] In some embodiments, step S101, obtaining the slice image for surface projection 3D printing may include: performing grayscale processing and binarization processing on the original slice image for surface projection 3D printing respectively to obtain the binary slice image.

[0076] Briefly speaking, the grayscale processing of an image is the process of converting a color image into a grayscale image; a color image is divided into three components, R, G, and B, which respectively display various colors such as red, green, and blue. Grayscale processing is the process of making the R, G, and B components of the color equal; pixels with larger grayscale values are brighter (the maximum pixel value is 255, which is white), and vice versa, darker (the minimum pixel value is 0, which is black). This process is the grayscale processing.

[0077] The binarization processing of an image is to make the grayscale value of each pixel in the pixel matrix of the image be 0 (black) or 255 (white), that is, to make the entire image show only black and white effects; in the grayscale image, the range of grayscale values is 0 to 255, and in the binarized image, the range of grayscale values is 0 or 255. The grayscale value of a pixel after grayscale processing can be converted to 0 or 255 (i.e., binarized) through a set threshold.

[0078] Taking the slice image as the binary slice image and the parameter as the grayscale value of the pixel as an example, the method of the embodiment of the present application will be described in detail through specific examples.

[0079] (1) Gray filling of the white area (i.e., the first image area, specifically representing the solid image area) of the binary slice image (without shelling):

[0080] In the embodiment of the present application, the binary slice image is obtained by slicing an unshelled three-dimensional model. The white area represents the solid image area. The white area needs to be replaced with a specified grayscale value. If there are holes in the solid image area (white area), the original grayscale (i.e., the first edge sub-area around the hole area in the white area) needs to be retained around the holes when replacing the white area with the specified grayscale value, and the grayscale serrations at the edge of the solid image area (i.e., the second edge sub-area of the white area except the first edge sub-area) also need to be retained. The partial sub-areas (pixel values) near the edge sub-area can be adjusted, and the grayscale values of some parts can be replaced (i.e., the width of the edge sub-area can be adjusted according to the actual situation). See Figure 5 , Figure 5 The left side of Figure 5 is the binary slice image before gray filling, and

[0081] The right side of

[0082] (1) Grayscale process and binarize the original image obtained by slicing the unshelled 3D model to obtain a binary image; Figure 6 On the left side of Figure 6 is the local original image, and on the right side of

[0083] (2) If there are holes in the solid image area, first obtain the hole area, as shown in Figure 7 .

[0084] (3) Dilate the obtained hole area. Subtract the hole area before dilation from the dilated hole area to obtain the outer ring image area around the hole area. Perform an AND operation on this outer ring image area and the binary image to obtain an inner ring measurement image area (i.e., the first edge sub-image area) that is consistent with the serrations of the hole area of the binary image, as shown in Figure 8 .

[0085] (4) Fill the hole area obtained in step (2) and erode the solid image area. Subtract the eroded solid image area from the solid image area before erosion and then perform an AND operation with the binary image to obtain a ring image area (where the factor is the same as that during dilation) that is consistent with the edge serrations of the solid image area, which is the second edge sub-image area, as shown in Figure 9 .

[0086] (5) Subtract the images obtained in steps (3) and (4) from the binary image respectively to obtain the internal sub-image area of the solid image area. Use the look-up table method to change the gray value of the pixels in the internal sub-image area to a specified gray value, as shown in Figure 10 .

[0087] (6) Add the images obtained in steps (3), (4), and (5) to obtain the target image, as shown in Figure 11 .

[0088] (II) Gray filling of the closed black area (i.e., the first image area, specifically representing the shelled image sub-area and the shell image sub-area) of the binary sliced image (shelled):

[0089] The binary sliced image in the embodiment of the present application is obtained by slicing the shelled 3D model. The black area is used to represent the shelled image sub-area, and the area enclosed by the edge of the shelled image sub-area is the shell image sub-area. The white area is used to represent the shell image sub-area (i.e., a circle of white on the edge). See Figure 12 . Figure 12 On the left side of Figure 12 is the binary sliced image before gray filling, and on the right side of

[0090] The specific implementation methods include:

[0091] (1) Perform grayscale processing and binarization processing on the original image obtained by slicing the three-dimensional model of the shelling to obtain a binary image.

[0092] (2) Find the hole area (i.e., the closed area), as Figure 13 shown.

[0093] (3) Use the look-up table method to change the grayscale value of the hole area, as Figure 14 shown.

[0094] (4) Add the image obtained in step (3) to the image in step (2) to obtain the target image, as Figure 15 shown.

[0095] (III) Gray filling of the black area (i.e., the first layer slice image area and other image areas) of the binary slice image:

[0096] In order to make the printed first layer fit better with the printing platform, the stereolithography area is usually enlarged. Here, the black area represents the first layer slice image area and other image areas used for printing the first layer. Therefore, the area with a grayscale value of 0 needs to be replaced with a specified grayscale value. If the specified grayscale value is greater than the grayscale value of the binary slice image, the grayscale value of the original pixel is replaced with the specified grayscale value. See Figure 16 , Figure 16 The left side of Figure 16 is the image before gray filling, and the right side of

[0097] is the target image after gray filling.

[0098] The embodiment of the present application also provides an image processing device for surface projection 3D printing. It should be noted that the device in the embodiment of the present application can implement the above-mentioned image processing method for surface projection 3D printing. For the detailed description of related content, please refer to the above method part and will not be repeated here.

[0099] The image processing device includes a processor and a memory. The memory is further configured to store a computer program. The processor is configured to execute the computer program and when executing the computer program, implement the image processing method for surface projection 3D printing as described in any one of the above.

[0100] Among them, the processor can be a microcontroller unit, a central processing unit, a digital signal processor, etc. The memory can be a Flash chip, a read-only memory, a magnetic disk, an optical disc, a USB flash drive, a mobile hard disk, etc.

[0101] An embodiment of the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor is caused to implement any one of the above-mentioned image processing methods for surface projection 3D printing. For a detailed description of the relevant content, please refer to the relevant content of the above-mentioned image processing method for surface projection 3D printing, which will not be elaborated here.

[0102] Among them, the computer-readable storage medium can be an internal storage unit of the above-mentioned device, such as a hard disk or a memory. The computer-readable storage medium can also be an external storage device, such as a plug-in hard disk, a smart memory card, a secure digital card, a flash card, etc.

[0103] It should be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0104] It should also be understood that the term "and / or" used in the specification and the appended claims of the present application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0105] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An image processing method for surface projection 3D printing, characterized in that, the method includes: obtaining a slice image for surface projection 3D printing; adjusting the parameters of a first image region in the slice image to obtain a target image. Compared with the first image region before parameter adjustment, when projected onto the photocuring region during surface projection 3D printing, the photocuring degree of the photocuring region onto which the first image region after parameter adjustment is projected during the surface projection 3D printing is reduced.

2. The method according to claim 1, characterized in that, the adjusting the parameters of the first image region in the slice image to obtain a target image includes: adjusting the parameters of the internal sub-image regions of the first image region and keeping the parameters of the edge sub-image regions of the first image region unchanged, thereby obtaining the target image.

3. The method according to claim 2, characterized in that, the slice image is obtained according to an unshelled three-dimensional model, and the first image region includes a solid image region; the adjusting the parameters of the internal sub-image regions of the first image region and keeping the parameters of the edge sub-image regions of the first image region unchanged, thereby obtaining the target image, includes: respectively determining the edge sub-image region of the solid image region and the internal sub-image region of the solid image region according to the slice image; adjusting the parameters of the internal sub-image region of the solid image region according to preset requirements to obtain the adjusted internal sub-image region of the solid image region; adding the adjusted internal sub-image region of the solid image region and the unadjusted edge sub-image region of the solid image region to obtain the target image.

4. The method according to claim 3, characterized in that, the respectively determining the edge sub-image region of the solid image region and the internal sub-image region of the solid image region according to the slice image includes: when the slice image further includes a hole image region and the hole image region is surrounded by the solid image region, respectively determining a first edge sub-image region of the solid image region located around the hole image region, a second edge sub-image region of the solid image region other than the first edge sub-image region, and the internal sub-image region of the solid image region according to the slice image; the adding the adjusted internal sub-image region of the solid image region and the unadjusted edge sub-image region of the solid image region to obtain the target image includes: adding the unadjusted first edge sub-image region of the solid image region, the adjusted internal sub-image region of the solid image region, and the unadjusted second edge sub-image region of the solid image region to obtain the target image.

5. The method according to claim 4, characterized in that, the respectively determining a first edge sub-image region of the solid image region located around the hole image region, a second edge sub-image region of the solid image region other than the first edge sub-image region, and the internal sub-image region of the solid image region according to the slice image includes: Dilate the hole image region in the slice image, subtract the hole image region before dilation from the dilated hole image region to obtain the outer ring image region around the hole image region, and perform an AND operation on the outer ring image region and the slice image to obtain a first edge sub-image region that is consistent with the edge shape of the hole image region; Fill the hole image region in the slice image and erode the solid image region. After subtracting the eroded solid image region from the solid image region before erosion and performing an AND operation with the slice image, obtain a second edge sub-image region that is consistent with the edge shape of the solid image region; Subtract the first edge sub-image region of the solid image region and the second edge sub-image region of the solid image region from the slice image respectively to obtain the internal sub-image region of the solid image region.

6. The method according to claim 2, wherein, the slice image is obtained from a shelled three-dimensional model, the first image region includes a closed shelled image region, and the shelled image region includes an internal shelled image sub-region and a shell image sub-region with a closed edge; Adjusting the parameters of the internal sub-image region of the first image region and keeping the parameters of the edge sub-image region of the first image region unchanged, thereby obtaining the target image, includes: Adjusting the parameters of the shelled image region according to preset requirements to obtain the shelled image region after adjusting the parameters; Adding the shelled image region after adjusting the parameters and the shelled image region before adjusting the parameters to obtain the target image.

7. The method according to any one of claims 1-6, wherein, the method includes: Obtaining a first-layer printing format image for surface projection 3D printing and adjusting the parameters within the first-layer printing format image region; Compared with the first-layer printing format image region before adjusting the parameters being projected onto the photocuring region during surface projection 3D printing, the photocuring degree of the photocuring region onto which the first-layer printing format image region after adjusting the parameters is projected during the surface projection 3D printing is increased.

8. The method according to claim 7, wherein, the first-layer printing format image includes a first-layer slice image region and other image regions; Adjusting the parameters within the first-layer printing format image region includes: Adjusting the parameters of the other image regions to obtain a target image of the adjusted other image regions; Compared with the other image regions before adjusting the parameters being projected onto the photocuring region during surface projection 3D printing, the photocuring degree of the photocuring region onto which the other image regions after adjusting the parameters are projected during the surface projection 3D printing is increased.

9. The method according to claim 8, wherein, Adjusting the parameters within the first-layer printing format image region includes: Adjusting the parameters of the first-layer slice image region to obtain a target image of the adjusted first-layer slice image region. Compared with the first-layer sliced image area before adjusting the parameters being projected onto the photocuring area during surface projection 3D printing, the photocuring degree of the light-curing area onto which the first-layer sliced image area after adjusting the parameters is projected during the surface projection 3D printing is increased.

10. The method according to claim 7, wherein, the sliced image includes a binary sliced image, and the parameter includes the gray value of the pixel.

11. The method according to claim 10, wherein, the obtaining of the sliced image for surface projection 3D printing includes: performing graying processing and binarization processing on the original sliced image for surface projection 3D printing respectively to obtain the binary sliced image.

12. An image processing apparatus for surface projection 3D printing, wherein, the image processing apparatus includes a processor and a memory, the memory is further configured to store a computer program, and the processor is configured to execute the computer program and when executing the computer program, implement the image processing method for surface projection 3D printing according to any one of claims 1-11.

13. A computer-readable storage medium, wherein, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor is caused to implement the image processing method for surface projection 3D printing according to any one of claims 1-11.

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