DTG printing method and system for automatic visual positioning of area-array camera

Abstract

The invention discloses a DTG printing method and system for automatic visual positioning of an area-array camera, and relates to the technical field of DTG printing, the DTG printing system comprises a camera module, an image RIP module and a printing equipment connection and configuration module, the camera module is responsible for image calibration, template matching and positioning mapping, and outputs a TIF image subjected to positioning processing; the image RIP module processes the TIF image and generates a printing control instruction; the printing equipment connection and configuration module is used for hardware integration connection and printing parameter configuration, the system automatically triggers image acquisition, the processed image is directly transmitted to a printer to complete printing, and calibration parameters can be repeatedly called only after single calibration to realize automatic continuous printing. The invention further provides an area-array camera automatic vision positioning DTG printing method, electronic equipment and a computer readable storage medium, operation process simplification and software integration are achieved, and production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of DTG printing technology, and more specifically, to a DTG printing method and system with automatic visual positioning of an area array camera. Background Art

[0002] In the field of digital printing, DTG printing technology is widely used because it can realize the direct printing of personalized small-batch color patterns. The core of this technology is to accurately position flexible materials such as cloth and T-shirts through a visual positioning system to ensure the position accuracy of the printed pattern. Early DTG printing equipment mainly relied on manual alignment or simple mechanical positioning, which was difficult to adapt to the positioning needs of complex curved surfaces or deformed materials, resulting in large printing deviations. With the development of machine vision technology, camera-based visual positioning systems have gradually become popular. By capturing material images and matching them with design patterns, positioning accuracy has been improved. However, the existing visual positioning DTG printing system still faces many challenges in actual production. From a software perspective, functions such as visual positioning, image RIP and printer control are implemented by independent software modules. Data interaction between software requires manual intervention. For example, TIF images need to be manually exported and imported into RIP software for processing. The operation process is cumbersome and prone to errors. From the perspective of hardware integration, the connection between the camera and the printer is complicated. Manual confirmation of the hardware status and adjustment of parameters are required before each print. Frequent manual operations lead to low production efficiency, especially in batch production. In addition, traditional systems have high technical requirements for operators. Not only do they need to master the parameter settings of the visual positioning software, but they also need to coordinate the cooperation between multiple software, which increases the company's labor costs and training difficulty. For scenarios that require frequent changes in printing materials, traditional systems require re-calibration of the camera and re-creation of templates each time, which cannot achieve automated continuous production and cannot meet the market demand for fast fashion, customization, and other markets with high requirements for production flexibility.

[0003] Therefore, the existing technology has the problems of cumbersome multi-software collaboration, many manual operations, low production efficiency, and high requirements for workers. Summary of the Invention

[0004] In order to overcome the problems of the existing technology such as cumbersome multi-software collaboration, multiple manual operations, low production efficiency, and high requirements for workers, the present invention discloses a DTG printing method and system with automatic visual positioning of an area array camera, which can effectively solve the problems of the above-mentioned existing technology.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A DTG printing system with automatic visual positioning of an area array camera, comprising:

[0007] The camera module is used to perform image calibration, template matching and positioning mapping operations, and output a TIF image after positioning processing;

[0008] An image RIP module, configured to perform RIP processing on the TIF image and generate a print control instruction;

[0009] Printing device connection and configuration module, used to integrate the area array camera and printer hardware and configure printing parameters;

[0010] The system automatically triggers image acquisition through the camera module, and directly transmits the positioned mapped image to the printer for printing after processing by the image RIP module. It only requires single calibration and repeated calling of calibration parameters to achieve automatic continuous printing.

[0011] Preferably, the camera module includes:

[0012] A camera calibration unit generates a camera calibration matrix based on the physical parameters of the printing plate;

[0013] Template making unit, creating material positioning template based on the first collected image;

[0014] An image positioning unit, which generates image positioning coordinates through a feature matching algorithm based on the calibration matrix and the positioning template;

[0015] The TIF image output unit converts the located image into TIF format and outputs the location mapping parameters.

[0016] Preferably, the camera calibration unit performs the following operations:

[0017] Establish a three-dimensional coordinate system with the center of the printing platen as the origin;

[0018] Compensate for lens distortion through bilinear interpolation algorithm;

[0019] According to formula M calib =K[R|T] to generate the calibration matrix, where K is the camera intrinsic parameter matrix and [R|T] is the extrinsic parameter matrix.

[0020] Preferably, the image RIP module includes:

[0021] Image enhancement submodule, which uses CLAHE algorithm to optimize the contrast of TIF images;

[0022] Color management submodule, which applies ICC color profiles for color space conversion;

[0023] The resolution conversion submodule resamples the image according to the printer DPI parameters.

[0024] Preferably, the printing device connection and configuration module includes:

[0025] Status monitoring unit, real-time acquisition of printer nozzle temperature and ink pressure parameters;

[0026] A dynamic compensation unit, adjusting the printing speed and ink output according to the state parameters;

[0027] The exception handling unit triggers the automatic cleaning procedure when it detects that the printing deviation exceeds the preset value.

[0028] Preferably, a method for automatically visually positioning DTG printing using an area array camera comprises the following steps:

[0029] In response to a single operation instruction from the user, the system is triggered to start acquiring a real-time image of the printing area through the area array camera;

[0030] Perform feature matching on the real-time image and the pre-stored template to generate positioning mapping data;

[0031] Performing deformation compensation on the original design image based on the mapping data, and performing RIP processing on the compensated image to generate a printing control instruction;

[0032] Send the print control instruction to the DTG printer and monitor the execution status.

[0033] Preferably, generating positioning mapping data includes:

[0034] Use SIFT algorithm to extract image feature points;

[0035] Eliminate mismatched point pairs using the RANSAC algorithm;

[0036] Calculate the affine transformation matrix to achieve image registration.

[0037] Preferably, the deformation compensation includes:

[0038] Generate a deformable mesh based on the mapping data;

[0039] Apply thin plate spline interpolation algorithm to perform nonlinear deformation on the image;

[0040] Bicubic convolution interpolation is used for pixel relocalization.

[0041] An electronic device includes a memory, a processor, and a computer program stored in the memory, wherein the processor implements the steps of the printing method described above when executing the program.

[0042] A computer-readable storage medium stores a computer program, which implements the steps of the printing method described above when executed by a processor.

[0043] Compared with the existing technology, the beneficial effects of the present invention are: traditional DTG printing requires the collaboration of multiple software and a large amount of manual operation, including manual control of camera image acquisition, positioning image output, etc. The camera module of this system automatically completes image calibration, template matching and positioning mapping, the image RIP module automatically processes the image and generates printing control instructions, the printing device connection and configuration module realizes hardware integrated connection and parameter configuration, and after the system responds to a single user instruction, it automatically triggers the camera to acquire images, image processing and printing to execute the entire process, simplifying the operation process, reducing worker operation requirements, reducing human errors, and improving production efficiency; integrating visual positioning, image RIP processing and printer control into one, changing the past mode of independent operation of each software, realizing functional collaboration, improving the integrity and smoothness of the system, facilitating operation management, and further improving production efficiency; only a single calibration is required, and the system repeatedly calls the calibration parameters to realize automatic continuous printing, avoiding repeated calibration steps, saving time and energy, improving printing efficiency, and stabilizing printing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the implementation methods or the description of the prior art. Obviously, the drawings described below are merely exemplary. For ordinary technicians in this field, other implementation drawings can be derived based on the provided drawings without any creative work.

[0045] Figure 1 It is a structural diagram of the system of the present invention;

[0046] Figure 2 It is an automatic printing flow chart of the system of the present invention;

[0047] Figure 3 It is a step diagram of the method of the present invention. DETAILED DESCRIPTION

[0048] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent;

[0049] In order to better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size;

[0050] It is understandable to those skilled in the art that some well-known structures and descriptions thereof may be omitted in the drawings.

[0051] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0052] Example 1

[0053] A DTG printing system with automatic visual positioning of an area array camera, comprising:

[0054] The camera module is used to perform image calibration, template matching and positioning mapping operations, and output a TIF image after positioning processing;

[0055] An image RIP module, configured to perform RIP processing on the TIF image and generate a print control instruction;

[0056] Printing device connection and configuration module, used to integrate the area array camera and printer hardware and configure printing parameters;

[0057] The system automatically triggers image acquisition through the camera module, and directly transmits the positioned mapped image to the printer for printing after processing by the image RIP module. It only requires single calibration and repeated calling of calibration parameters to achieve automatic continuous printing.

[0058] The camera module includes:

[0059] A camera calibration unit generates a camera calibration matrix based on the physical parameters of the printing plate;

[0060] Template making unit, creating material positioning template based on the first collected image;

[0061] An image positioning unit, which generates image positioning coordinates through a feature matching algorithm based on the calibration matrix and the positioning template;

[0062] The TIF image output unit converts the located image into TIF format and outputs the location mapping parameters.

[0063] The camera calibration unit performs the following operations:

[0064] Establish a three-dimensional coordinate system with the center of the printing platen as the origin;

[0065] Compensate for lens distortion through bilinear interpolation algorithm;

[0066] According to formula M calib =K[R|T] to generate the calibration matrix, where K is the camera intrinsic parameter matrix and [R|T] is the extrinsic parameter matrix.

[0067] The image RIP module includes:

[0068] Image enhancement submodule, which uses CLAHE algorithm to optimize the contrast of TIF images;

[0069] Color management submodule, which applies ICC color profiles for color space conversion;

[0070] The resolution conversion submodule resamples the image according to the printer DPI parameters.

[0071] The printing device connection and configuration module includes:

[0072] Status monitoring unit, real-time acquisition of printer nozzle temperature and ink pressure parameters;

[0073] A dynamic compensation unit, adjusting the printing speed and ink output according to the state parameters;

[0074] The exception handling unit triggers the automatic cleaning procedure when it detects that the printing deviation exceeds the preset value.

[0075] See also Figure 1-2 ,This embodiment proposes a DTG printing system with automatic visual positioning of an area array camera, ,which can realize fast and accurate printing of T-shirt patterns.

[0076] The camera module is responsible for performing image calibration, template matching, and positioning mapping operations, and ultimately outputs a TIF image after positioning processing. Specifically, the camera module includes the following key units:

[0077] When the camera calibration unit is used for the first time, it generates a camera calibration matrix based on the physical parameters of the printing platen. First, a three-dimensional coordinate system with the center of the printing platen as the origin is established. Then, the lens distortion is compensated by the bilinear interpolation algorithm. Finally, according to the calibration formula M calib =K[R|T] to generate the calibration matrix, where K is the camera intrinsic parameter matrix and [R|T] is the extrinsic parameter matrix.

[0078] The template production unit creates a material positioning template based on the T-shirt image collected for the first time. The staff manually outlines the outline of the designated printing area on the chest of the T-shirt in the system and marks key feature points, such as the lower edge of the neckline, the intersection of the left bust line, etc., to form a template.

[0079] During the printing task, the image positioning unit generates image positioning coordinates through a feature matching algorithm based on the calibration matrix and positioning template, uses the SIFT algorithm to extract image feature points, and then uses the RANSAC algorithm (the RANSAC (Random Sample Consensus) algorithm is an iterative estimation method used to estimate the parameters of a mathematical model from a data set containing outliers. It has a wide range of applications in computer vision, image processing, and robotics, especially in model fitting, feature matching, and image registration) to eliminate mismatched point pairs. Finally, the affine transformation matrix is calculated to achieve image registration and determine the relationship between the actual position of the T-shirt chest and the template position.

[0080] The TIF image output unit converts the located image into TIF format and outputs the positioning mapping parameters, including image translation, rotation angle, scaling ratio, etc., to ensure that the image corresponds to the actual position of the T-shirt.

[0081] The image RIP module is used to perform RIP processing on TIF images and generate print control instructions. This module contains the following submodules:

[0082] The image enhancement submodule uses the CLAHE algorithm (adaptive histogram equalization algorithm) to optimize the contrast of TIF images, divides the image into small blocks, and performs histogram equalization on each block to limit the contrast to avoid excessive amplification of noise, thereby improving the clarity of pattern contours and the vividness of colors.

[0083] The color management submodule applies the ICC color profile to perform color space conversion, converting the image from the RGB color space to the printer's CMYK color space, ensuring that the printed color can accurately restore the color of the design draft.

[0084] The resolution conversion submodule resamples the image according to the printer's DPI parameters, calculates the grayscale value or color value of the newly added pixels through an interpolation algorithm, and increases the image resolution to match the printer's requirements, avoiding image blurring, jagged edges, and other problems during printing.

[0085] The printing device connection and configuration module is used to integrate the area array camera and printer hardware and configure printing parameters. This module includes the following units:

[0086] The status monitoring unit obtains parameters such as the printer nozzle temperature and ink pressure in real time to ensure that the nozzle temperature is stable at 35-40°C and the ink pressure is within the range of 0.8-1.2bar.

[0087] The dynamic compensation unit adjusts the printing speed and ink output according to the state parameters. If the nozzle temperature is too high, the printing speed is reduced by 10-20%; if the ink pressure is insufficient, the ink output is appropriately increased to ensure printing quality.

[0088] When the exception handling unit detects that the printing deviation exceeds a preset value (such as 0.5mm), it triggers the automatic cleaning program to clean the print head and then recalibrate.

[0089] The workflow of the system is as follows: When used for the first time, the area array camera is installed 60 cm above the printing platen of the DTG printer. The lens passes through the surface light source with the central opening and is installed coaxially. It is fixed with sheet metal to ensure that the camera is perpendicular to the printing platen. The camera is connected to the printing device and configuration module via the USB3.0 interface, and the printer is connected to the module via the LAN interface.

[0090] Perform camera calibration to establish a three-dimensional coordinate system with the center of the printing platen as the origin. Use a bilinear interpolation algorithm to compensate for lens distortion. Generate a calibration matrix based on the calibration formula. Then, create a material positioning template based on the first captured T-shirt image and mark key feature points.

[0091] In subsequent printing tasks, the system is triggered to start by responding to a single user operation instruction. The area array camera obtains a real-time image of the T-shirt printing area, performs feature matching on the real-time image with the pre-stored template, generates positioning mapping data, uses the SIFT algorithm to extract image feature points, uses the RANSAC algorithm to eliminate mismatched point pairs, and calculates the affine transformation matrix to achieve image registration.

[0092] The original design image is deformed and compensated based on the positioning mapping data. A deformed mesh is generated according to the mapping data. The image is nonlinearly deformed using the thin plate spline interpolation algorithm. Pixels are relocated using bicubic convolution interpolation to make the pattern adapt to the actual posture of the T-shirt.

[0093] The compensated image is RIP processed to generate printing control instructions. The image enhancement submodule improves the image contrast. The color management submodule converts the color space. The resolution conversion submodule adjusts the image resolution. Then, the printing control instructions are sent to the DTG printer and the execution status is monitored. The printing device connection and configuration module monitors the printer status parameters in real time. The dynamic compensation unit adjusts the printing speed and ink output according to the parameters. The exception handling unit triggers the automatic cleaning program when it detects that the offset exceeds the standard.

[0094] The system automatically triggers image acquisition through the camera module, and the positioned mapped image is processed by the image RIP module and then directly transmitted to the printer for printing. It only requires a single calibration and repeated calling of the calibration parameters to achieve automatic continuous printing, which improves the efficiency and accuracy of T-shirt printing and meets the demand for efficient and precise production in the field of personalized customization of textiles.

[0095] Example 2

[0096] A DTG printing method using an area array camera for automatic visual positioning includes the following steps:

[0097] In response to a single operation instruction from the user, the system is triggered to start acquiring a real-time image of the printing area through the area array camera;

[0098] Perform feature matching on the real-time image and the pre-stored template to generate positioning mapping data;

[0099] Performing deformation compensation on the original design image based on the mapping data, and performing RIP processing on the compensated image to generate a printing control instruction;

[0100] Send the print control instruction to the DTG printer and monitor the execution status.

[0101] Generating positioning mapping data includes:

[0102] Use SIFT algorithm to extract image feature points;

[0103] Eliminate mismatched point pairs using the RANSAC algorithm;

[0104] Calculate the affine transformation matrix to achieve image registration.

[0105] The deformation compensation comprises:

[0106] Generate a deformable mesh based on the mapping data;

[0107] Apply thin plate spline interpolation algorithm to perform nonlinear deformation on the image;

[0108] Bicubic convolution interpolation is used for pixel relocalization.

[0109] An electronic device includes a memory, a processor, and a computer program stored in the memory, wherein the processor implements the steps of the printing method described above when executing the program.

[0110] A computer-readable storage medium stores a computer program, which implements the steps of the printing method described above when executed by a processor.

[0111] In the specific implementation, please refer to Figure 2-3 When used for the first time, a camera calibration matrix is generated according to the physical parameters of the printing platen, a three-dimensional coordinate system with the center of the printing platen as the origin is established, the lens distortion is compensated by the bilinear interpolation algorithm, and a calibration matrix is generated according to the calibration formula. Then, a material positioning template is created based on the first collected T-shirt image, and key feature points are marked.

[0112] In response to a single user operation command, the system is triggered to start. The area array camera obtains a real-time image of the T-shirt printing area, performs feature matching on the real-time image with the pre-stored template, generates positioning mapping data, uses the SIFT algorithm to extract image feature points, uses the RANSAC algorithm to eliminate mismatched point pairs, and calculates the affine transformation matrix to achieve image registration.

[0113] Based on the positioning mapping data, the original design image is deformed and compensated. A deformation mesh is generated according to the mapping data. The thin plate spline interpolation algorithm is applied to perform nonlinear deformation on the image. Bicubic convolution interpolation is used for pixel repositioning. The compensated image is then RIP processed to generate printing control instructions. The image enhancement submodule improves the image contrast, the color management submodule converts the color space, and the resolution conversion submodule adjusts the image resolution.

[0114] Send printing control instructions to the DTG printer and monitor the execution status. The printing device connection and configuration module monitors the printer status parameters in real time. The dynamic compensation unit adjusts the printing speed and ink output according to the parameters. The exception handling unit triggers the automatic cleaning program when the deviation exceeds the standard. This method realizes the precise positioning and efficient printing of T-shirt patterns through automated image acquisition, feature matching, deformation compensation and RIP processing. Only a single calibration and repeated call of the calibration parameters are required to realize automatic continuous printing, which improves the efficiency and accuracy of T-shirt printing and meets the demand for efficient and precise production in the field of personalized customization of textiles.

[0115] The same or similar reference numerals correspond to the same or similar components;

[0116] The terms used in the drawings to describe positional relationships are for illustrative purposes only and should not be construed as limiting this patent;

[0117] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the field, 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 methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A DTG printing system with automatic visual positioning of an area array camera, characterized in that: include: The camera module is used to perform image calibration, template matching and positioning mapping operations, and output a TIF image after positioning processing; An image RIP module, configured to perform RIP processing on the TIF image and generate a print control instruction; Printing device connection and configuration module, used to integrate the area array camera and printer hardware and configure printing parameters; The system automatically triggers image acquisition through the camera module, and directly transmits the positioned mapped image to the printer for printing after processing by the image RIP module. It only requires single calibration and repeated calling of calibration parameters to achieve automatic continuous printing.

2. The printing system according to claim 1, wherein: The camera module includes: A camera calibration unit generates a camera calibration matrix based on the physical parameters of the printing plate; Template making unit, creating material positioning template based on the first collected image; An image positioning unit, which generates image positioning coordinates through a feature matching algorithm based on the calibration matrix and the positioning template; The TIF image output unit converts the located image into TIF format and outputs the location mapping parameters.

3. The printing system according to claim 2, wherein: The camera calibration unit performs the following operations: Establish a three-dimensional coordinate system with the center of the printing platen as the origin; Compensate for lens distortion through bilinear interpolation algorithm; According to formula M calib =K[R|T] to generate the calibration matrix, where K is the camera intrinsic parameter matrix and [R|T] is the extrinsic parameter matrix.

4. The printing system according to claim 1, wherein: The image RIP module includes: Image enhancement submodule, which uses CLAHE algorithm to optimize the contrast of TIF images; Color management submodule, which applies ICC color profiles for color space conversion; The resolution conversion submodule resamples the image according to the printer DPI parameters.

5. The printing system according to claim 1, wherein: The printing device connection and configuration module includes: Status monitoring unit, real-time acquisition of printer nozzle temperature and ink pressure parameters; A dynamic compensation unit, adjusting the printing speed and ink output according to the state parameters; The exception handling unit triggers the automatic cleaning procedure when it detects that the printing deviation exceeds the preset value.

6. A DTG printing method using automatic visual positioning of an area array camera, used to implement the printing system according to any one of claims 1 to 5, characterized in that: The following steps are involved: In response to a single operation instruction from the user, the system is triggered to start acquiring a real-time image of the printing area through the area array camera; Perform feature matching on the real-time image and the pre-stored template to generate positioning mapping data; Performing deformation compensation on the original design image based on the mapping data, and performing RIP processing on the compensated image to generate a printing control instruction; Send the print control instruction to the DTG printer and monitor the execution status.

7. The printing method according to claim 6, characterized in that: Generating positioning mapping data includes: Use SIFT algorithm to extract image feature points; Eliminate mismatched point pairs using the RANSAC algorithm; Calculate the affine transformation matrix to achieve image registration.

8. The printing method according to claim 7, wherein: The deformation compensation comprises: Generate a deformable mesh based on the mapping data; Apply thin plate spline interpolation algorithm to perform nonlinear deformation on the image; Bicubic convolution interpolation is used for pixel relocalization.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory, wherein: When the processor executes the program, the steps of the printing method according to any one of claims 6 to 8 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the printing method according to any one of claims 6 to 8 are implemented.

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