Automatic visual positioning printing method and system based on double-platen printer

Abstract

The invention discloses an automatic visual positioning printing method and system based on a double-platen printer, and relates to the technical field of digital textile printing, a double-platen control module is responsible for switching between two printing platens, and an image acquisition module comprises two area-array cameras used for acquiring material dynamic images; the image processing module comprises a calibration unit and a positioning unit, the positioning unit dynamically selects a rigid body or deformation positioning mode according to material deformation characteristics, the positioning mapping module carries out deformation correction on a pattern according to a positioning result and generates a TIF image, and the RIP processing module converts the TIF image into a printing instruction stream; according to the automatic vision positioning printing method and system based on the double-platen printer, the manual dependence is reduced, and the automatic vision positioning printing method and system based on the double-platen printer are suitable for modern flexible and high-throughput production requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of digital textile printing, and more specifically, to an automatic vision positioning printing method and system based on a double platen printer. Background Art

[0002] In the field of DTG printing, traditional technologies mostly adopt a single platen design in combination with a vision positioning system, which has many drawbacks. On the one hand, the single platen cannot perform material loading and unloading and printing simultaneously. When the device executes a printing task, it is necessary to wait for the printing to be completed before the material can be loaded and unloaded, resulting in a large amount of idle time during the production process of the device, low utilization rate, and difficulty in meeting the requirements of modern production for high-efficiency and continuous operation. On the other hand, existing positioning systems mostly rely on independent vision positioning software, image RIP software, and printer control software. The operation process is cumbersome and complex. From image acquisition to positioning processing and then to printing output, manual intervention is required to switch software interfaces multiple times, which not only increases the operation difficulty but also is prone to human errors, greatly limiting the improvement of production efficiency. Especially when facing a large number of orders, the problem of low production efficiency is more prominent. In view of these pain points, the present invention proposes an automatic vision positioning printing system and method based on a double platen printer. Through the alternating operation of the double platens and in combination with a highly integrated software control system, while one platen is performing a printing operation, the other platen can simultaneously perform material loading or unloading and image positioning calculation, effectively reducing the waiting time of the device and reducing the dependence on manual operation, promoting the development of DTG printing technology towards higher efficiency and more intelligent directions, and meeting the production requirements of modern flexibility and high throughput.

[0003] Existing single platen DTG printers are inefficient and cumbersome to operate, and cannot meet the needs of modern production. Summary of the Invention

[0004] In order to overcome the problems of low efficiency and cumbersome operation of existing single platen DTG printers and their inability to meet the needs of modern production, the present invention discloses an automatic vision positioning printing method and system based on a double platen printer, which can effectively solve the above technical problems.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows:

[0006] An automatic vision positioning printing system based on a double platen printer, comprising:

[0007] A double platen control module for switching between two printing platens in response to an external instruction;

[0008] An image acquisition module, including two area cameras, adjustable light sources, and trigger interfaces respectively corresponding to the two printing platens, for acquiring dynamic images of the materials on the target platen;

[0009] The image processing module further includes:

[0010] A calibration unit for mapping image pixel coordinates to the world coordinate system of the printing device;

[0011] A positioning unit, including a rigid body positioning subunit and a deformation positioning subunit, dynamically selects a positioning mode according to the material deformation characteristics;

[0012] A positioning mapping module, performs deformation correction on the target pattern according to the positioning result and generates a TIF image;

[0013] A RIP processing module for converting the TIF image into an instruction stream recognizable by the printing device;

[0014] A printer control module, sends the instruction stream to the corresponding printing device according to the platen number;

[0015] An integrated control module for triggering the entire process of image acquisition, processing, and printing.

[0016] Preferably, when the double platen control module performs a switching operation, it includes:

[0017] Closing the hardware trigger channel of the current platen camera;

[0018] Loading the calibration parameter set and template database pre-stored in the target platen;

[0019] Enabling the light source control signal and image acquisition interface of the target platen.

[0020] Preferably, the positioning unit includes:

[0021] A feature analysis subunit for calculating the local gradient change rate of the material image;

[0022] A mode selector, activates the deformation positioning subunit when the gradient change rate exceeds a preset threshold, otherwise activates the rigid body positioning subunit.

[0023] Preferably, the deformation positioning subunit performs the following:

[0024] Extracting the SURF feature point set on the material surface;

[0025] Constructing a Delaunay triangular mesh model;

[0026] Calculating the vertex displacement vector through a non-rigid optimization algorithm:

[0027]

[0028] where, L is the Laplacian operator matrix, λ is the elastic coefficient, Denotes the square of the modulus after multiplying the Laplacian matrix by D. Denotes the square of the modulus of D.

[0029] Preferably, the positioning mapping module adopts the thin plate spline interpolation algorithm:

[0030] Generate the pattern pixel mapping relationship according to the displacement field:

[0031]

[0032] Where Is the feature point weight, Is the radial basis function, Denotes the pixel value of the corrected image at the coordinate (x, y), p is the position of the feature point corresponding to the current pixel position to be calculated, Is the position of the i-th feature point, Denotes the pixel value of the original image at the coordinate At, ( , ) Is the displacement vector, used to find the corresponding pixel position in the original image according to the displacement field.

[0033] Preferably, it further includes an exception handling module:

[0034] Real-time monitor the positioning confidence and image clarity indicators;

[0035] When the confidence is lower than the threshold, automatically switch the positioning mode and trigger image re-acquisition;

[0036] Generate a warning report including coordinate deviation.

[0037] Preferably, in the image acquisition module:

[0038] The area array camera is vertically installed at a preset height above the platen;

[0039] The adjustable light source is a bar light source with brightness self-adaptation, installed directly below the area array camera;

[0040] The trigger interface receives the differential signal sent by the printing device.

[0041] An automatic vision positioning printing method based on a double-platen printer includes the following steps: Activate the area array camera of the target platen through the double-platen control module, collect the dynamic image of the material and perform coordinate calibration;

[0042] Dynamically select the rigid body positioning or deformation positioning mode based on the gradient change rate. The dynamic selection of the positioning mode includes: calculating the local gradient change rate of the material image; when the gradient change rate exceeds the first threshold and the texture consistency is lower than the second threshold, activate the deformation positioning mode; otherwise, activate the rigid body positioning mode;

[0043] Perform deformation correction on the target pattern according to the positioning result, convert the corrected image into a print instruction stream through RIP processing, and trigger the printing device to execute the printing operation.

[0044] Preferably, a computer-readable storage medium stores a computer program, and when the program is executed by a processor, the above-mentioned printing method is implemented.

[0045] Compared with the prior art, the beneficial effects of the present invention are as follows: By adopting the method of alternating operation of double platens, the present invention solves the problems of low efficiency and cumbersome operation of traditional single-platen DTG printers, improves production efficiency, and meets the needs of modern production. Specifically, the double-platen control module can quickly switch between two printing platens. When one platen is performing a printing task, the other platen can synchronously perform material loading or unloading and image positioning calculation. This parallel operation significantly reduces the equipment waiting time and improves equipment utilization rate; the two area array cameras equipped in the image acquisition module can respectively perform dynamic image acquisition on the materials on the two platens. With the adjustable light source and trigger interface, it ensures that the acquired images are clear and accurate, providing a reliable data basis for positioning and correction; the calibration unit and positioning unit in the image processing module can dynamically select the positioning mode according to the material deformation characteristics. Whether it is rigid body positioning or deformation positioning, it can accurately complete the positioning task. The positioning mapping module performs deformation correction on the target pattern according to the positioning result and generates a TIF image, providing accurate pattern information for printing; the RIP processing module and the printer control module cooperate closely to convert the TIF image into an instruction stream recognizable by the printing device and send the instruction stream to the corresponding printing device according to the platen number, ensuring the efficient execution of the printing task; the integrated control module realizes the full-process automatic control from image acquisition, processing to printing output, reduces manual intervention, and reduces the dependence on skilled workers; through the collaborative work of these modules, not only the printing efficiency is improved, but also the printing quality is improved, realizing efficient and accurate DTG printing. Description of the Drawings

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained according to the provided drawings.

[0047] Figure 1 It is a block diagram of the module composition of the system of the present invention;

[0048] Figure 2 It is an automatic printing flow chart of the system of the present invention. Detailed implementation mode

[0049] The attached drawings are only for illustrative purposes and should not be construed as a limitation of this patent;

[0050] To better illustrate this embodiment, some components in the attached drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product;

[0051] For those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted.

[0052] The technical solution of the present invention will be further described below in conjunction with the attached drawings and embodiments.

[0053] Embodiment 1

[0054] An automatic vision positioning printing system based on a double platen printer, comprising:

[0055] A double platen control module for switching between two printing platens in response to an external instruction;

[0056] An image acquisition module, including two area array cameras, adjustable light sources and trigger interfaces respectively corresponding to two printing platens, for acquiring dynamic images of materials on the target platen;

[0057] The image processing module further includes:

[0058] A calibration unit for mapping image pixel coordinates to the world coordinate system of the printing device;

[0059] A positioning unit, including a rigid body positioning sub-unit and a deformation positioning sub-unit, dynamically selecting a positioning mode according to the material deformation characteristics;

[0060] A positioning mapping module for correcting the deformation of the target pattern according to the positioning result and generating a TIF image;

[0061] A RIP processing module for converting the TIF image into an instruction stream recognizable by the printing device;

[0062] A printer control module for sending the instruction stream to the corresponding printing device according to the platen serial number;

[0063] An integrated control module for triggering the entire process of image acquisition, processing and printing.

[0064] When the double platen control module performs the switching operation, it includes:

[0065] Closing the hardware trigger channel of the current platen camera;

[0066] Loading the calibration parameter set and template database pre-stored on the target platen;

[0067] Enable the light source control signal and image acquisition interface of the target platform.

[0068] The positioning unit comprises:

[0069] The feature analysis subunit is used to calculate the local gradient change rate of the material image;

[0070] Mode selector, activates the deformation positioning subunit when the gradient change rate exceeds a preset threshold, otherwise activates the rigid body positioning subunit.

[0071] The deformation positioning subunit performs the following steps:

[0072] Extract SURF feature point set of material surface;

[0073] Construct a Delaunay triangulated mesh model;

[0074] Compute the vertex displacement vectors using a non-rigid optimization algorithm:

[0075]

[0076] Where L is the Laplace operator matrix, λ is the elastic coefficient, represents the square of the modulus length after the Laplace operator matrix is multiplied by D, Denotes the square of the modulus of D.

[0077] The positioning mapping module adopts the thin plate spline interpolation algorithm:

[0078] Generate pattern pixel mapping relationship based on displacement field:

[0079]

[0080] in, is the feature point weight, is the radial basis function, represents the pixel value of the corrected image at the coordinate (x, y), p is the position of the feature point corresponding to the current pixel position to be calculated, is the position of the i-th feature point, Represents the original image at coordinates The pixel value at ( , ) is the displacement vector, which is used to find the corresponding pixel position in the original image based on the displacement field.

[0081] Also includes exception handling module:

[0082] Real-time monitoring of positioning reliability and image clarity indicators;

[0083] When the confidence level is lower than the threshold, the positioning mode is automatically switched and image re-acquisition is triggered;

[0084] Generate a warning report containing coordinate deviations.

[0085] In the image acquisition module:

[0086] The area array camera is vertically installed at a preset height above the platen;

[0087] The adjustable light source is a bar-shaped light source with brightness self-adaptation, installed directly below the area array camera;

[0088] The trigger interface receives the differential signal sent by the printing device.

[0089] Please refer to Figure 1 , the dual-platen control module is used to respond to external instructions and switch between two printing platens. When a platen needs to be switched, it will first close the hardware trigger channel of the current platen camera, then load the pre-stored calibration parameter set and template database of the target platen, and finally enable the light source control signal and image acquisition interface of the target platen to ensure that image acquisition and processing can be smoothly carried out on the new platen.

[0090] The image acquisition module is equipped with two area array cameras, corresponding to two printing platens respectively, as well as an adjustable light source and a trigger interface, installed at a preset height above the platen. The adjustable light source is a bar-shaped light source with brightness self-adaptation, located directly below the area array camera. The trigger interface receives the differential signal sent by the printing device, thereby acquiring the dynamic image of the material on the target platen and providing the original data for subsequent image processing.

[0091] The image processing module is divided into a calibration unit and a positioning unit. The calibration unit maps the image pixel coordinates to the world coordinate system of the printing device through a specific calibration method to ensure that the coordinate information in the image can accurately correspond to the actual printing position. The positioning unit includes a rigid body positioning sub-unit and a deformation positioning sub-unit, as well as a feature analysis sub-unit and a mode selector. The feature analysis sub-unit calculates the local gradient change rate of the material image. The mode selector activates the corresponding positioning sub-unit according to whether the gradient change rate exceeds a preset threshold. If it exceeds the threshold, the deformation positioning sub-unit is activated, otherwise the rigid body positioning sub-unit is activated to dynamically select the positioning mode according to the material deformation characteristics and improve the positioning accuracy.

[0092] After the positioning unit completes the positioning, the positioning mapping module performs deformation correction on the target pattern according to the positioning result and generates a TIF image. The thin plate spline interpolation algorithm is used to generate the pattern pixel mapping relationship based on the displacement field, so as to ensure that the generated TIF image can accurately reflect the actual shape and position of the material and provide accurate image information for subsequent printing.

[0093] The RIP processing module receives the TIF images generated by the positioning and mapping module, converts them into an instruction stream recognizable by the printing device, and transforms the image data into commands that the printer can execute, such as the actions of the print heads and the ink ejection volume, etc., to achieve precise control of the printing process.

[0094] The printer control module sends the instruction stream processed by RIP to the corresponding printing device according to the platen number, ensuring that the instructions can be accurately transmitted to the corresponding printer. At the same time, it manages the print job queue, avoids print job conflicts, and ensures the orderly progress of the printing process.

[0095] The integrated control module is used to trigger the entire process of image acquisition, processing, and printing, realizing seamless connection of each link and improving the overall operation efficiency of the system.

[0096] The exception handling module monitors the positioning confidence and image clarity indicators in real time. When the confidence is lower than the threshold, it automatically switches the positioning mode and triggers re-acquisition of the image. At the same time, it generates a warning report containing coordinate deviations, discovers and processes possible problems in a timely manner, and ensures the stability and reliability of the system.

[0097] Embodiment 2

[0098] An automatic vision positioning printing method based on a dual-platen printer includes the following steps: activating the area array camera of the target platen through the dual-platen control module, collecting the dynamic image of the material and performing coordinate calibration;

[0099] Dynamically select the rigid body positioning or deformation positioning mode based on the gradient change rate. The dynamic selection of the positioning mode includes: calculating the local gradient change rate of the material image; when the gradient change rate exceeds the first threshold and the texture consistency is lower than the second threshold, activate the deformation positioning mode; otherwise, activate the rigid body positioning mode;

[0100] Perform deformation correction on the target pattern according to the positioning result, convert the corrected image into a print instruction stream through RIP processing, and trigger the printing device to execute the printing operation.

[0101] A computer-readable storage medium stores a computer program, and when the program is executed by a processor, it implements the above-mentioned printing method.

[0102] Please refer to Figure 2 , turn on the automatic vision positioning printing system based on the dual-platen printer. The staff inputs instructions on the operation interface, and activates the area array camera of one of the printing platens through the dual-platen control module. At this time, the adjustable light source of this platen is lit, and the camera is ready to start collecting the dynamic image of the material.

[0103] The activated area array camera, assisted by the adjustable light source, vertically captures the image of the material above the platen. The trigger interface in the image acquisition module receives the differential signal sent by the printing device to ensure the synchronization and accuracy of image acquisition. The captured image is transmitted to the calibration unit of the image processing module. The calibration unit uses the pre-stored calibration parameters to map the pixel coordinates of the image to the world coordinate system of the printing device, completing the coordinate calibration and making the coordinate information in the image correspond to the actual printing position.

[0104] The feature analysis sub-unit of the image processing module analyzes the captured material image, calculates the local gradient change rate of the image, and the mode selector compares the calculated gradient change rate with a preset first threshold. At the same time, it evaluates whether the texture consistency of the image is lower than the second threshold. If the gradient change rate exceeds the first threshold and the texture consistency is lower than the second threshold, it is determined that the material has deformed and the deformation positioning mode is activated; otherwise, if the gradient change rate does not exceed the first threshold or the texture consistency is not lower than the second threshold, the rigid body positioning mode is activated to select a suitable positioning method for the positioning operation.

[0105] In the rigid body positioning mode, according to the rigid body transformation model, traditional object detection and matching algorithms are used to quickly determine the position and orientation of the material on the platen; in the deformation positioning mode, first, the SURF feature point set on the surface of the material is extracted to construct a Delaunay triangular mesh model, and then the vertex displacement vector is calculated through a non-rigid optimization algorithm

[0106]

[0107] where L is the Laplacian operator matrix and λ is the elastic coefficient, represents the square of the modulus of the product of the Laplacian operator matrix and D, represents the square of the modulus of D, thus realizing the precise positioning of the material and obtaining the accurate position information and deformation conditions of the material.

[0108] The positioning result is transmitted to the positioning mapping module, which corrects the deformation of the target pattern according to the positioning result, adopts the thin plate spline interpolation algorithm, and generates the pattern pixel mapping relationship based on the displacement field

[0109]

[0110] where, is the feature point weight, is the radial basis function, represents the pixel value of the corrected image at the coordinate (x, y), p is the position of the feature point corresponding to the current pixel position to be calculated, is the position of the i-th feature point, represents the original image at the coordinate The pixel value at ( , ) is the displacement vector, which is used to find the corresponding pixel position in the original image according to the displacement field. The corrected image pixel value is obtained through interpolation calculation, and the corrected TIF image is generated to make the pattern match the actual shape and position of the material, thereby improving the printing accuracy.

[0111] The RIP processing module receives the corrected TIF image and converts the TIF image into an instruction stream recognizable by the printing device according to the requirements and settings of the printing device, converting the image data into commands that the printer can execute, such as the movement trajectory of the print head, the ink ejection volume, etc., to generate detailed printing instructions and provide an operation guide that can be directly executed by the printing device.

[0112] The printer control module sends the generated printing instruction stream to the corresponding printing device according to the platen serial number. After receiving the instruction, the printing device executes the printing task and precisely prints the pattern on the material. During the printing process, the printer control module manages the printing task queue to avoid task conflicts, ensures the smooth progress of the printing process, and simultaneously monitors the printing status in real time and promptly handles possible abnormal situations.

[0113] The exception handling module monitors the positioning confidence and image clarity indicators in real time. If, during the positioning or image processing process, it is found that the positioning confidence is lower than the set threshold, indicating possible inaccurate positioning or poor image quality, it will automatically switch the positioning mode and trigger image re-acquisition, re-perform positioning and processing, and simultaneously generate a warning report containing coordinate deviations to remind the staff to pay attention and handle it in a timely manner to ensure that the printing quality meets the requirements.

[0114] Like or similar reference numerals correspond to like or similar components;

[0115] The terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation of this patent;

[0116] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. An automatic vision positioning printing system based on a double platen printer, characterized in that, It includes: A dual platen control module for switching between two printing platens in response to an external instruction; An image acquisition module, including two area cameras, an adjustable light source and a trigger interface respectively corresponding to the two printing platens, for acquiring the dynamic image of the material on the target platen; The image processing module further includes: A calibration unit for mapping the image pixel coordinates to the world coordinate system of the printing device; A positioning unit, including a rigid body positioning sub-unit and a deformation positioning sub-unit, dynamically selecting a positioning mode according to the material deformation characteristics; A positioning mapping module for performing deformation correction on the target pattern according to the positioning result and generating a TIF image; A RIP processing module for converting the TIF image into an instruction stream recognizable by the printing device; A printer control module for sending the instruction stream to the corresponding printing device according to the platen serial number; An integrated control module for triggering the entire process of image acquisition, processing and printing.

2. The printing system according to claim 1, characterized in that, When the dual platen control module performs the switching operation, it includes: Closing the hardware trigger channel of the current platen camera; Loading the calibration parameter set and template database pre-stored on the target platen; Enabling the light source control signal and image acquisition interface of the target platen.

3. The printing system according to claim 1, wherein The positioning unit includes: A feature analysis sub-unit for calculating the local gradient change rate of the material image; A mode selector for activating the deformation positioning sub-unit when the gradient change rate exceeds a preset threshold, otherwise activating the rigid body positioning sub-unit.

4. The printing system according to claim 3, wherein When the deformation positioning sub-unit executes, it includes: Extracting the SURF feature point set on the material surface; Constructing a Delaunay triangular mesh model; Calculating the vertex displacement vector through a non-rigid optimization algorithm: where L is the Laplacian matrix and λ is the elastic coefficient, represents the square of the norm of the product of the Laplacian matrix and D, represents the square of the norm of D.

5. The printing system according to claim 1, wherein The positioning mapping module adopts a thin plate spline interpolation algorithm: Generating a pattern pixel mapping relationship according to the displacement field: ; among them, is the feature point weight, is the radial basis function, represents the pixel value of the corrected image at the coordinate (x, y), p is the position of the feature point corresponding to the pixel position to be calculated currently, is the position of the i-th feature point, represents the pixel value of the original image at the coordinate , ([[]] , ) is the displacement vector, which is used to find the corresponding pixel position in the original image according to the displacement field.

6. The printing system according to claim 1, wherein It also includes an exception handling module: Real-time monitoring of the positioning confidence and image clarity indicators; When the confidence is lower than the threshold, automatically switching the positioning mode and triggering image re-acquisition; Generating a warning report including coordinate deviation.

7. The printing system according to claim 1, characterized in that, In the image acquisition module: The area camera is vertically installed at a preset height above the platen; The adjustable light source is a bar-shaped light source with adaptive brightness, installed directly below the area camera; The trigger interface receives the differential signal sent by the printing device.

8. A printing method based on the system according to any one of claims 1-7, characterized in that It includes the following steps: Activating the area camera of the target platen through the dual platen control module, acquiring the dynamic image of the material and performing coordinate calibration; Dynamically selecting the rigid body positioning or deformation positioning mode based on the gradient change rate. The dynamic selection of the positioning mode includes: calculating the local gradient change rate of the material image; when the gradient change rate exceeds the first threshold and the texture consistency is lower than the second threshold, activating the deformation positioning mode; otherwise activating the rigid body positioning mode; Performing deformation correction on the target pattern according to the positioning result, converting the corrected image through RIP processing into a printing instruction stream, and triggering the printing device to execute the printing operation.

9. A computer-readable storage medium storing a computer program, characterized in that, When the program is executed by the processor, it implements the printing method described in claim 8.

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