CN119459126B

CN119459126B - Printing deviation correction method for roller printing machine and roller printing machine

Info

Publication number: CN119459126B
Application number: CN202510073711.XA
Authority: CN
Inventors: 王霞; 吕志威; 刘鸿磊
Original assignee: Shenzhen Gimech Technology Corp
Current assignee: Shenzhen Gimech Technology Corp
Priority date: 2025-01-17
Filing date: 2025-01-17
Publication date: 2025-03-21
Anticipated expiration: 2045-01-17
Also published as: CN119459126A

Abstract

The invention is suitable for the technical field of image data processing, and provides a printing deviation correcting method of a roller printer and the roller printer. The printed object surface image is then acquired in real time, the surface area is extracted, and compared to a standard printed image. And calculating pixel difference values among the image areas, counting the pixel number of which the difference value exceeds a threshold value, and judging whether the set pixel number threshold value is exceeded or not. If the distance between the feature points and the object contour exceeds the preset distance, the feature points of the first image area and the second image area are extracted, and displacement and scaling correction parameters are calculated according to the distance between the feature points and the object contour. Finally, the printing parameters of the roll printer are adjusted to correct the deviation. The method improves the real-time performance and the deviation correction precision of deviation monitoring through intelligent and automatic means, and overcomes the defects in the traditional method.

Description

Printing deviation correcting method of roll printing machine and roll printing machine

Technical Field

The invention belongs to the technical field of image data processing, and particularly relates to a printing deviation correcting method of a roll printing machine and the roll printing machine.

Background

With the increasing demand of modern electronic products for high performance and miniaturization, the design and manufacturing process of electronic components is also continuously developing. Multilayer chip ceramic capacitors (MLCCs) are a common electronic component that plays an important role in modern electronic devices, particularly in smart phones, computers and other high precision circuits. In the production of MLCCs, an accurate surface printing process is required to ensure connection and functional implementation between different electrodes on a multilayer ceramic substrate.

In the manufacture of multilayer ceramic capacitors, conventional roll printers are widely used to print multicolor patterns, particularly for precise pattern lamination on the surface of ceramic substrates. With the wide application of electronic components such as Multi-LAYER CERAMIC Capacitor (MLCC), printing technology is facing higher demands. The manufacture of MLCCs generally requires precise multi-layer printing, with the alignment, size and location of each layer of printed pattern having to be tightly controlled. Therefore, how to accurately control the printing process of the roll printer, and avoid quality problems caused by position deviation or dimensional errors, becomes one of key technologies for improving production efficiency and product quality.

However, conventional printing deviation correcting methods often rely on manual inspection or simple mechanical adjustment, and cannot accurately monitor and correct deviations occurring in the printing process in real time.

Disclosure of Invention

In view of the above, the embodiment of the invention provides a printing deviation rectifying method of a roll printing machine and the roll printing machine, so as to solve the technical problem that the traditional printing deviation rectifying method often depends on manual inspection or simple mechanical adjustment and cannot accurately monitor and rectify deviation in the printing process in real time.

A first aspect of an embodiment of the present invention provides a printing deviation rectifying method for a roll printing machine, including:

The method comprises the steps of obtaining a plurality of color layers of a printing pattern and standard printing object surface images corresponding to the color layers, wherein the color layers are used for multicolor overprinting to form the printing pattern, and the standard printing object surface images are standard printing images obtained by sequentially superposing the color layers on preset positions of the object images, wherein different color layers have different printing sequences;

Collecting an object surface image of a printed color image layer in real time, and extracting an object surface area in the object surface image;

Extracting a first image area of an object surface area and a second image area of a current standard printed object surface image, wherein the current standard printed object surface image refers to a standard printed object surface image corresponding to a printed color image layer;

calculating pixel difference values of the same pixel positions between the first image area and the second image area, and counting the number of pixel positions of which the pixel difference values are larger than a first threshold value;

Acquiring a plurality of first characteristic points of the first image area and a plurality of second characteristic points of the second image area when the number of pixel positions is larger than a second threshold value;

matching displacement correction parameters according to first distances between a plurality of first characteristic points and the outline of the object, wherein the displacement correction parameters are used for correcting the position deviation of the conveying direction;

calculating a scaling correction parameter according to the distance difference between the first feature points and the second feature points, wherein the scaling correction parameter is used for correcting overlong or overlong longitudinal dimension of the printed color layer;

and adjusting the printing parameters of the roll printer according to the displacement deviation correcting parameters and/or the scaling deviation correcting parameters.

Further, the step of acquiring the object surface image of the printed color image layer in real time and extracting the object surface area in the object surface image includes:

Acquiring surface color information of a transmission structure;

removing an image area corresponding to the surface color information in the object surface image to obtain an object image;

identifying a plurality of first feature points in the object image;

calculating a current direction vector formed by two target first feature points, and acquiring a standard direction vector of the target first feature points, wherein the standard direction vector refers to a direction vector formed by the two target first feature points when the surface of an object is in a correct direction;

calculating an included angle between the current direction vector and the standard direction vector;

And rotating the object image to the direction corresponding to the standard direction vector based on the included angle to obtain the object surface area.

Further, the step of extracting the first image area of the object surface area and the second image area of the current standard print object surface image includes:

Extracting a first current object surface area corresponding to a first preset area position from the object surface area, wherein the first preset area position is a preset image area and is used for extracting a key area of the object surface, and the key area is an object surface area used for bearing a printing pattern;

Adjusting the image size of the current standard printing object surface image to a target size according to the alignment parameter corresponding to the shooting distance to obtain an adjusted current standard printing object surface image, wherein the target size is consistent with the image size of the object surface image;

extracting a second current object surface area corresponding to the first preset area position from the adjusted current standard printed object surface image;

acquiring original pixel value information of the key area of the object surface;

Removing the original pixel value information in the first current object surface area to obtain the first image area;

and eliminating the original pixel value information in the second current object surface area to obtain the second image area.

Further, the step of identifying a plurality of first feature points in the object image includes:

The method comprises the steps of obtaining a second preset area of a first characteristic point and a standard reference image of the first characteristic point, wherein the second preset area is a preset image area and is used for reducing a retrieval area of the first characteristic point;

traversing each current pixel point in the second preset area, and extracting a rectangular pixel area based on each current pixel point, wherein the rectangular pixel area is a fixed-size area and takes the current pixel point as a center;

calculating the similarity between the rectangular pixel area and the standard reference picture;

taking a rectangular pixel area corresponding to the maximum similarity as a first characteristic area;

and taking the center of the first characteristic area as the first characteristic point.

Further, the step of calculating the similarity between the rectangular pixel region and the standard reference map includes:

Respectively taking the same diagonal points of the rectangular pixel area and the standard reference picture as origin points of a coordinate system;

Calculating pixel difference values between two pixel points of the rectangular pixel area and the same coordinate position in the standard reference image, wherein the image sizes of the rectangular pixel area and the standard reference image are consistent;

Counting pixel point values of which the pixel difference value is smaller than a third threshold value in the rectangular pixel area;

and dividing the pixel point value by the number of all the pixel points in the rectangular pixel area to obtain the similarity.

Further, the step of matching the displacement correction parameter according to the first distances between the plurality of first feature points and the object contour includes:

calculating a first center position of the surface profile of the object;

Calculating second center positions of the plurality of first feature points;

Acquiring the center position of the object surface profile and the center position of the second characteristic point in the adjusted current standard printing object surface image;

calculating a second distance between the first center position and the second center position;

calculating a third distance between the center position of the object surface profile and the center position of the second feature point;

Calculating a first difference between the second distance and the third distance;

if the first difference value is larger than a fourth threshold value, determining a deviation rectifying direction according to the positive and negative values of the first difference value;

and multiplying the first difference value by a mapping coefficient to obtain the displacement deviation correcting parameter.

Further, the step of calculating the scaling correction parameter according to the distance differences between the plurality of first feature points and the plurality of second feature points includes:

establishing a first coordinate system by taking a preselected first characteristic point as an origin;

calculating a fourth distance between a preselected first feature point and other first feature points, wherein the other first feature points refer to feature points except the preselected first feature point in a plurality of first feature points;

Establishing a second coordinate system by taking the corresponding point of the preselected second characteristic point as an origin, wherein the preselected first characteristic point and the preselected second characteristic point are the same characteristic point on the surface of the object;

calculating a fifth distance between a preselected second feature point and other second feature points, wherein the other second feature points refer to feature points except the preselected second feature point in a plurality of second feature points;

Calculating a second difference value between a fourth distance and a fifth distance corresponding to the same feature point on the surface of the object;

If the average value of the second difference values is larger than a fifth threshold value, calculating a scaling deviation correcting parameter by adopting a feedback control algorithm based on the second difference values.

A second aspect of an embodiment of the present invention provides a printing deviation correcting device of a roll printing machine, including:

the device comprises a first acquisition unit, a first printing unit and a second acquisition unit, wherein the first acquisition unit is used for acquiring a plurality of color layers of a printing pattern and standard printing object surface images corresponding to the color layers, the color layers are used for multicolor overprinting to form the printing pattern, and the standard printing object surface images are standard printing images obtained by sequentially superposing the color layers on preset positions of the object images, wherein different color layers have different printing sequences;

The acquisition unit is used for acquiring the object surface image of the printed color image layer in real time and extracting an object surface area in the object surface image;

The device comprises an extraction unit, a display unit and a display unit, wherein the extraction unit is used for extracting a first image area of an object surface area and a second image area of a current standard printed object surface image, and the current standard printed object surface image refers to a standard printed object surface image corresponding to a printed color image layer;

A first calculating unit, configured to calculate a pixel difference value of the same pixel position between the first image area and the second image area, and count the number of pixel positions where the pixel difference value is greater than a first threshold;

A second obtaining unit configured to obtain, when the number of pixel positions is greater than a second threshold, a plurality of first feature points of the first image area and a plurality of second feature points of the second image area;

the matching unit is used for matching displacement correction parameters according to first distances between a plurality of first characteristic points and the outline of the object, wherein the displacement correction parameters are used for correcting the position deviation of the conveying direction;

The second calculation unit is used for calculating a scaling deviation correction parameter according to the distance difference between the first characteristic points and the second characteristic points, wherein the scaling deviation correction parameter is used for correcting overlong or overlong longitudinal dimension of the printed color layer;

and the adjusting unit is used for adjusting the printing parameters of the roll printing machine according to the displacement deviation correcting parameters and/or the scaling deviation correcting parameters.

A third aspect of an embodiment of the present invention provides a roll printing machine, including a roller system, a camera, a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor executes the computer program to implement the steps of the printing deviation correcting method of the roll printing machine according to the first aspect.

A fourth aspect of the embodiments of the present invention provides a computer readable storage medium storing a computer program which, when executed by a processor, implements the steps of the printing deviation rectifying method of the roll printing machine according to the first aspect.

Compared with the prior art, the embodiment of the invention has the beneficial effects that the pattern deviation can be accurately identified by collecting the object surface image of the printed color layer in real time and comparing the object surface image with the standard printed object surface image, the delay of manual intervention is avoided, and the accuracy of pattern alignment in the printing process is ensured. According to the invention, manual participation is not needed, the image processing technology is utilized to automatically extract the object surface area and calculate the image difference, so that the manual inspection error is effectively avoided, the production efficiency and the precision are improved, and the manual error rate is reduced. And (3) calculating the distance between the pixel difference value of the image area and the object contour by analyzing the matching of the pixel difference value and the characteristic point, so that the deviation correction parameter is accurately matched. The process can be adjusted in real time in the printing process, ensures that each layer of color of the pattern is accurately aligned, and improves the quality and consistency of multicolor overprinting. The method is suitable for overprinting of different color layers, wherein the printing sequence of each color layer is possibly different, can flexibly adapt to various printing scenes, and ensures that the high-level printing precision can be maintained even in the multicolor printing process. Through timely adjustment printing deviation, the rejection rate caused by overlarge deviation is avoided, and meanwhile, the time cost of manual inspection and adjustment is reduced, so that the overall production efficiency is improved. Because the deviation can be corrected in real time in the printing process, the invention can effectively avoid printing defects such as pattern overlapping, color deviation and the like, ensure high-quality output of each printing period and improve the overall quality and the aesthetic degree of printed articles. In a word, the printing deviation correcting method of the roll printer solves the problems of untimely deviation monitoring, low deviation correcting precision and the like which are common in the traditional method through an intelligent and automatic technical means, and can greatly improve the printing quality and the production efficiency.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments or the related technical descriptions will be briefly described, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 shows a schematic flow chart of a printing deviation correcting method of a roll printer provided by the invention;

FIG. 2 is a schematic diagram of a printing deviation correcting device of a roll printing machine according to an embodiment of the present invention;

fig. 3 shows a schematic view of a roll printing machine according to an embodiment of the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

The embodiment of the invention provides a printing deviation correcting method of a roller printing machine and the roller printing machine, which are used for solving the technical problems that the traditional printing deviation correcting method often depends on manual inspection or simple mechanical adjustment and cannot accurately monitor and correct deviation in the printing process in real time.

First, the invention provides a printing deviation rectifying method of a roll printer. The printing deviation correcting method of the roller printer is applied to the roller printer, and the roller printer comprises, but is not limited to, a roller system, a camera, a memory, a processor and a printing deviation correcting program of the roller printer, wherein the printing deviation correcting program is stored on the memory and can run on the processor. Referring to fig. 1, fig. 1 is a schematic flow chart of a printing deviation rectifying method of a roll printing machine according to the present invention. As shown in fig. 1, the printing deviation rectifying method of the roll printer may include the following steps:

Step 101, acquiring a plurality of color layers of a printing pattern and standard printing object surface images corresponding to the color layers, wherein the color layers are used for multicolor overprinting to form the printing pattern, and the standard printing object surface images are standard printing images obtained by sequentially superposing the color layers on preset positions of the object images, wherein different color layers have different printing sequences;

in multicolor printing, the printed pattern is formed by the superposition of different color layers. Each color layer represents a portion of the printing, the layers being superimposed in a particular order.

For each combination of color layers, a "standard" image is generated, which refers to the resulting printed image on the object surface in a predetermined color overlay sequence. This is an ideal image and should in theory be highly consistent with the actual printed image.

102, Acquiring an object surface image of a printed color image layer in real time, and extracting an object surface area in the object surface image;

During the printing process, the object surface image of the finished color image layer is acquired in real time. These images are used to compare with standard images to detect deviations between actual printing and standard printing.

The surface area of the object is extracted from the acquired image. The surface area, i.e. the actual area of the print, does not include background or extraneous parts, facilitating subsequent image analysis and comparison. The specific logic for extracting the object surface area in the object surface image is as follows:

specifically, step 102 specifically includes steps 1021 through 1026:

step 1021, obtaining surface color information of the conveying structure;

First, it is necessary to acquire color data on the surface of a conveying structure (such as a conveyor belt) during printing. These color information are the colors of the conveyor belt itself. By eliminating the image area corresponding to the surface color information, only the effective area related to the surface of the object is ensured to be extracted, redundant background or interference information is effectively removed, and the extraction precision of the surface area of the object is improved.

Step 1022, eliminating the image area corresponding to the surface color information in the object surface image to obtain an object image;

In order to accurately extract the printed area of the object, it is necessary to reject this part of the color area, ensuring that the subsequent image processing is focused only on the actual printed pattern on the object surface. After being removed, the object image is obtained, namely the image with the background interference removed.

Step 1023, identifying a plurality of first feature points in the object image;

specifically, step 1023 specifically includes steps A1 to A5:

A1, acquiring a second preset area of a first characteristic point and a standard reference image of the first characteristic point, wherein the second preset area is a preset image area and is used for reducing a retrieval area of the first characteristic point;

The second preset area is a predefined image area for limiting the retrieval range of the feature points. By limiting the search area, full graph traversal is avoided, and algorithm efficiency is improved. This area is to narrow the search range so as to concentrate on the area possibly containing the first feature point, reducing unnecessary computation.

The standard reference image is a standard image corresponding to the "first feature area". The standard reference map is an ideal image representing the "first feature region". And comparing the feature points with each candidate region in the current image to judge whether the feature points meet the standard of the feature points.

A2, traversing each current pixel point in the second preset area, and extracting a rectangular pixel area based on each current pixel point, wherein the rectangular pixel area is a fixed-size area and takes the current pixel point as a center;

this step examines whether each pixel point of the second preset area is the center of the potential first feature point one by traversing the pixel points. The traversal process ensures that all possible areas in the image are considered, avoiding missing key feature points.

And for each traversed current pixel point, taking the pixel point as a center, and extracting a rectangular pixel area with a fixed size. The size of this rectangular area is preset and the position is determined based on the center of the current pixel point.

A3, calculating the similarity between the rectangular pixel area and the standard reference graph;

For each extracted rectangular pixel area, the similarity with the standard reference image is calculated. The goal is to find out the area most conforming to the standard diagram, i.e. "most similar area", by calculating the matching degree of each rectangular area with the standard reference diagram.

Specifically, step A3 specifically includes steps a31 to a34:

A31, respectively taking the same diagonal points of the rectangular pixel area and the standard reference picture as origin points of a coordinate system;

to ensure accuracy of contrast, the corresponding diagonal points of the rectangular pixel region and the standard reference map are taken as the origin of the coordinate system. The two diagonal points of the rectangular area and the reference map will be aligned in the coordinate system, ensuring that the same-position pixels can be directly compared.

A32, calculating pixel difference values between two pixel points of the rectangular pixel area and the same coordinate position in the standard reference image, wherein the image sizes of the rectangular pixel area and the standard reference image are consistent;

for pixels at each corresponding position of the rectangular pixel region and the standard reference map, differences thereof are calculated. The purpose of this step is to quantify the difference in color or brightness for each pair of pixels as the basis for subsequent similarity calculations.

A33, counting pixel point values of which the pixel difference value is smaller than a third threshold value in the rectangular pixel area;

A third threshold is set, and if the pixel difference value of each pair of pixel points in the rectangular pixel area and the standard reference diagram is smaller than the threshold, the difference between the two pixel points is considered to be negligible, which means that the two pixel points are similar. And counting the number of pixel points with pixel difference values smaller than a third threshold value by traversing all pixels of the rectangular region. These pixel points will be considered similar to the corresponding pixel points in the standard reference map.

And step A34, dividing the pixel point value by the number of all the pixel points in the rectangular pixel area to obtain the similarity.

The similarity is calculated based on the ratio of the "number of similar pixels" to the "total number of pixels in the rectangular region". This step represents the similarity of the rectangular area and the standard reference graph by the ratio, and the closer the value is to 1, the more similar the two are, and the closer the value is to 0, the larger the difference is. The similarity value can be used to determine whether the rectangular region is a valid matching region of the standard reference map.

In this embodiment, by taking the same diagonal point of the rectangular pixel area and the standard reference image as the origin of the coordinate system and performing difference calculation on the pixel points at the same coordinate position, the difference between the two pixels can be accurately measured. The method ensures that the difference of all pixel positions can be accurately captured in the comparison process, thereby improving the accuracy of similarity calculation. And dividing the pixel point number with the statistical pixel difference value smaller than a preset threshold value by the total pixel point number of the rectangular pixel area, thereby obtaining the similarity. By the method, the similarity degree between the rectangular area and the reference graph can be rapidly evaluated, the complexity of global comparison is avoided, and the calculation efficiency is improved. A third threshold is set to determine whether the pixel difference is within an acceptable range, so that the technical scheme can adapt to different image characteristics and noise influences. The setting of the third threshold can be adjusted according to the requirements of specific application scenes, so that the method is flexibly suitable for various image quality and detail requirements, and the robustness of the method is enhanced. By counting pixels whose pixel difference is smaller than the third threshold, those differences caused by noise or slight distortion can be effectively ignored. Such processing helps ensure that the final similarity value reflects true image similarity, reducing the likelihood of false positives. The calculation of the similarity only depends on simple comparison and statistics of pixel differences, and the operation is simple and efficient, and can be completed rapidly in real-time application. The scheme does not need complex mathematical models or algorithms, and reduces the calculation cost. The calculated similarity is more accurate through the fine comparison of each pixel point, and the subsequent image processing and feature point extraction are facilitated.

A4, taking a rectangular pixel area corresponding to the maximum similarity as a first characteristic area;

after traversing all rectangular pixel regions, the region most similar to the standard reference map is selected. This region is considered as the region most conforming to the first feature point criterion, i.e., the first feature region.

The region corresponding to the maximum similarity should have the strongest degree of matching with the standard reference map visually, so this step ensures accurate positioning of the feature points.

And A5, taking the center of the first characteristic area as the first characteristic point.

In this embodiment, by limiting the feature point identification to the second preset area, the search range is reduced, and the efficiency and accuracy of feature point search are greatly improved. The method can effectively avoid blind searching in the whole graph range, so that each first characteristic point is accurately positioned, and the identification accuracy is ensured. And carrying out matching calculation on each rectangular pixel area by using a standard reference graph, wherein the position with the maximum similarity is the area where the first feature point is located. By the method, the region most matched with the standard reference diagram can be automatically identified, so that accurate positioning of the feature points is ensured, and misidentification caused by image deformation or noise interference is reduced. By limiting the second preset area to the preset image area and extracting a rectangular pixel area with a fixed size from each pixel point, the system can avoid processing too large or irrelevant areas in calculation, and the calculation efficiency of the characteristic point identification process is improved. Compared with the traditional feature point extraction method which simply relies on edge detection or color features, the method has the advantage that the extracted first feature point is more accurate and reliable by carrying out similarity calculation on the standard reference graph. Through maximum similarity matching, false recognition caused by image noise, blurring or surface deformation can be effectively reduced, and accuracy and reliability of feature points are ensured. The automatic feature point extraction process of the technical scheme does not depend on manual intervention. By accurately identifying a plurality of feature points in the object image, base data may be provided for subsequent calculations.

Step 1024, calculating a current direction vector formed by two target first feature points and obtaining a standard direction vector of the target first feature points, wherein the standard direction vector refers to a direction vector formed by the two target first feature points when the surface of the object is in the correct direction, and the target first feature points refer to first feature points which are preselected for direction correction;

Two target feature points are selected, and a vector between the two target feature points is calculated and is called a current direction vector. This vector describes the directional relation in the object image, i.e. the direction in which the two feature points are formed during the actual printing process.

Standard direction vector-a standard direction is preset, and this direction represents the ideal vector between two characteristic points of the object surface in the correct direction. The normal direction vector is the theoretically correct direction, is usually well defined at design time and ensures the correct alignment of the printed pattern.

Step 1025, calculating an included angle between the current direction vector and the standard direction vector;

And comparing the included angle between the current direction vector and the standard direction vector, and calculating the deviation degree between the current direction vector and the standard direction vector. This angle value reflects the difference between the actual printing direction of the object surface and the intended correct direction.

And 1026, rotating the object image to the direction corresponding to the standard direction vector based on the included angle to obtain the object surface area.

And rotating the object image according to the calculated included angle so that the current direction vector is aligned with the standard direction vector. By the rotation operation, the deviation of the direction in the image can be corrected, and the print pattern of the object image can be adjusted to the correct direction. As a result of this step, the surface area of the object is properly directionally corrected for subsequent analysis or print calibration. After the direction correction is completed, the actual printed area (corrected aligned area) of the object surface is obtained. This is the area that is ultimately used for further print correction or image analysis.

In this embodiment, only the effective area related to the object surface is ensured to be extracted by removing the image area corresponding to the surface color information, so that redundant background or interference information is effectively removed, and the extraction accuracy of the object surface area is improved. By identifying a plurality of first feature points in the object image and calculating the included angle between the current direction vector and the standard direction vector, the direction deviation of the object can be accurately obtained. The process can effectively correct the direction error caused by equipment deviation or inaccurate object positioning in the printing process, and ensure the accuracy of the image direction. By pre-selecting the first characteristic points of the target for direction correction, characteristic point matching can be intelligently performed, and the correct direction of the object surface can be accurately identified. The calculated included angle enables the object image to accurately rotate to the standard direction, and automation and accuracy of image processing are greatly improved. Compared with the traditional manual inspection and adjustment method, the invention adopts an automatic image processing technology, can collect and correct the object surface direction in real time in the actual production process, avoids the time delay and error of manual intervention, and improves the production efficiency and the automation degree of the production line. Through accurate direction correction, the accurate alignment of the printed patterns on the surface of the object can be ensured, and the printing defects of pattern distortion, overlapping or dislocation caused by the direction error of the object are reduced, so that the overall printing quality is improved, and the accurate alignment of the pattern layers of various colors is ensured especially in the multicolor printing process. The technical scheme of the invention realizes rapid and accurate object surface area extraction and direction correction.

Step 103, extracting a first image area of an object surface area and a second image area of a current standard printed object surface image, wherein the current standard printed object surface image refers to a standard printed object surface image corresponding to a printed color image layer;

the first image area is a portion extracted from the acquired actual printed image and represents the printed area of the object.

The second image area is a corresponding area extracted from the "standard print object surface image" for comparison with the actual print image.

Since different color layers correspond to different standard printed object surface images, it is necessary to match the current standard printed object surface image to which the printed color layers correspond.

Specifically, step 103 specifically includes steps 1031 to 1036:

step 1031, extracting a first current object surface area corresponding to a first preset area position from the object surface area, wherein the first preset area position is a preset image area and is used for extracting a key area of the object surface, and the key area is an object surface area used for bearing a printing pattern;

The first predetermined area location is a predetermined area in the object surface area indicating a critical area on the object surface. This critical area is the portion carrying the printed pattern. Based on this first preset region position, a corresponding region is extracted from the object surface image. The purpose of the extraction is for subsequent analysis and comparison, in particular for identifying the printed pattern areas of the object surface.

Step 1032, adjusting the image size of the current standard printing object surface image to a target size according to the alignment parameter corresponding to the shooting distance to obtain an adjusted current standard printing object surface image, wherein the target size is consistent with the image size of the object surface image;

The variation in the imaging distance may cause the captured images to vary in size. By acquiring an alignment parameter related to the imaging distance, the size of the image can be adjusted to match the target size. The size of the current standard print object surface image is adjusted to be consistent with the target size using the alignment parameters. The target size is typically the size of the image that matches the actual size of the object surface to ensure that the elements in the image match the ratio of the actual object surface area.

Step 1033, extracting a second current object surface area corresponding to the first preset area position from the adjusted current standard printing object surface image;

After the image size is adjusted, the corresponding region is extracted from the adjusted standard printed object surface image based on the preset region position again. At this time, since the image size has been adjusted, the extracted area should be matched with the actual area in the object surface area. This ensures that the extracted areas have dimensions and positions that are consistent with the actual object surface.

Step 1034, obtaining original pixel value information of the key area of the object surface;

the original pixel value information refers to original pixel value information of the key region when not printed.

Step 1035, eliminating the original pixel value information in the first current object surface area to obtain the first image area;

a first image area is obtained by removing specific pixel information from the first current object surface area. Such culling may be for the deletion of background, noise or unwanted image portions in order to highlight critical areas or to remove irrelevant information, thereby improving the effectiveness of the image processing.

And 1036, eliminating the original pixel value information in the second current object surface area to obtain the second image area.

Similarly, the original pixel value information is removed from the second current object surface area, resulting in a second image area. Similar to the rejection process of the first image region, the rejection operation ensures that the region actually required to be analyzed can be focused on in subsequent processes and comparisons.

In this embodiment, by setting the first preset area position, the key area carrying the printed pattern in the surface of the object is accurately extracted. The method ensures that the extracted image area contains the most critical part related to the printed pattern, avoids the interference of irrelevant areas, and improves the accuracy and the effectiveness of image processing. According to the invention, the size of the current standard printing object surface image is adjusted according to the alignment parameters corresponding to the shooting distance, so that the adjusted standard image size is consistent with the image size of the object surface area. Through the adjustment, the problem of unmatched image sizes is solved, uniform dimensions among different images are ensured in the image comparison and region extraction processes, and the alignment accuracy of the images is effectively improved. By extracting the corresponding first current object surface area and second current object surface area from the object surface area and standard printed image area, respectively, and removing the original pixel value information, clean first image area and second image area can be obtained efficiently. This operation ensures that unnecessary background information is removed, thereby improving the accuracy of image processing and the effectiveness of subsequent analysis.

104, Calculating pixel difference values of the same pixel positions between the first image area and the second image area, and counting the number of pixel positions of which the pixel difference values are larger than a first threshold value;

and respectively establishing a coordinate system at the same diagonal points of the first image area and the second image area. Pixel points at which the same pixel positions are acquired in the first image region and the second image region are acquired, and pixel difference values are calculated. The pixel difference value being greater than the first threshold value indicates a greater pixel value difference between the two.

Step 105, when the number of pixel positions is larger than a second threshold value, acquiring a plurality of first characteristic points of the first image area and a plurality of second characteristic points of the second image area;

The number of pixel positions with larger differences is counted. If the number is larger than the second threshold value, the whole printing process is proved to have larger deviation, and correction processing is needed.

A plurality of feature points are extracted from the first image region and the second image region, the feature points typically being portions of the image having significant variations, capable of representing the structure of the image. By calculating the distances between the feature points and the object contour, the deviation of the image position can be obtained, and the nature and the size of the deviation can be further determined.

Step 106, matching displacement correction parameters according to first distances between a plurality of first characteristic points and the object contour, wherein the displacement correction parameters are used for correcting the position deviation of the conveying direction;

specifically, step 106 specifically includes steps 1061 to 1068:

Step 1061, calculating a first center position of the surface profile of the object;

First, the geometric center (i.e., centroid) of the contour is calculated from the contour lines or boundaries of the object surface. This center position represents the geometric center of the object contour and is the reference point for subsequent correction and comparison.

Step 1062, calculating a second center position of the plurality of first feature points;

the first feature points are points (e.g., corner points, key mark points, etc.) of the object surface or in the printed pattern that have distinct features. By calculating the geometric centers of these feature points, their second center positions are obtained. This is the average position of the plurality of feature points and is typically used to describe the overall position of the feature point population.

Step 1063, obtaining the adjusted center position of the object surface contour and the second feature point center position in the current standard printing object surface image;

It is understood that the object surface contour center position and the second feature point center position are correct center positions as standard reference positions, and whether the second center position is displaced is determined based on the distance between the object surface contour center position and the second feature point center position being correct center positions.

Step 1064, calculating a second distance between said first center position and said second center position;

the difference in Euclidean distance or other metric between a first center location of the object surface profile and a second center location of the plurality of first feature points is calculated. By calculating the distance between these two center positions, the relative displacement between the object profile and the feature point population can be estimated.

Step 1065, calculating a third distance between the center position of the object surface contour and the center position of the second feature point;

It will be appreciated that the third distance is the correct standard distance and the second distance is the distance that occurs during actual printing.

Step 1066, calculating a first difference between said second distance and said third distance;

And calculating the difference between the second distance and the third distance to obtain a first difference. This difference reflects the relative displacement change between the object profile and the feature point center position. The larger the difference value is, the more obvious the position shift of the contour and the feature point is.

Step 1067, if the first difference value is greater than the fourth threshold value, determining a deviation rectifying direction according to the positive and negative values of the first difference value;

And setting a fourth threshold value for judging whether displacement correction is needed. If the first difference exceeds the threshold, a larger displacement deviation exists, and correction processing is needed. And judging the deviation rectifying direction according to the positive and negative values of the first difference value. For example, if the first difference is positive, indicating that the actual position of the object deviates from a certain direction (e.g., the conveying direction), a correction is required in the opposite direction.

Step 1068, multiplying the first difference value by a mapping coefficient to obtain the displacement correction parameter.

In order to convert the displacement difference into the actual offset correction, a mapping coefficient is used. This coefficient converts the difference into an actual displacement correction for adjusting the positioning of the image or object. And obtaining a final displacement deviation correcting parameter by multiplying the first difference value with the mapping coefficient.

In this embodiment, by calculating the first center position of the object surface profile and the second center positions of the plurality of first feature points, accurate positioning of the object surface and the feature points is achieved. The accurate calculation of the two center positions provides a basis for the subsequent error correction and displacement correction, and ensures the accuracy of the correction process. By calculating the second distance between the first center position and the second center position and the third distance between the center position of the object surface profile and the center position of the second feature point, the displacement error between the object profile and the feature point can be accurately measured. By comparing the two distances, the deviation between the object position and the image coordinates can be effectively identified. The method and the device judge the deviation rectifying direction according to the positive and negative values of the difference value by calculating the first difference value between the second distance and the third distance. When the first difference value is larger than the fourth threshold value, whether deviation correction is needed or not can be intelligently judged, and the deviation correcting direction is determined. The mechanism can dynamically adjust deviation correcting parameters, flexibly respond under different conditions and ensure accurate positioning of images or objects. The displacement correction parameter is obtained by multiplying the first difference value and the mapping coefficient, and the technology realizes automatic correction parameter adjustment. Through the algorithm, the system can automatically adjust the deviation rectifying force according to the actual error, and manual intervention is not needed, so that the processing efficiency and accuracy are improved. According to the technical scheme, the deviation between the object and the standard image can be accurately detected, and the image position is dynamically adjusted, so that the alignment accuracy of the surface of the object and the printed pattern is improved. During long-term or high-speed production, small deviations between the object and the image may gradually accumulate, thereby affecting the product quality. By means of the technology, displacement is corrected in real time, error accumulation can be effectively avoided, consistent precision of production of each batch can be ensured, and quality fluctuation and unqualified products are reduced. The technology can accurately calculate the relative position difference between the object surface and the image characteristic points, and can effectively improve the precision of an automatic detection and calibration system. In summary, the invention can efficiently and accurately correct the displacement of the image or the object by calculating the first distance, the second distance and the third distance, intelligently judging the correction direction and adjusting the displacement correction parameter.

Step 107, calculating a scaling deviation correcting parameter according to the distance difference between the first feature points and the second feature points, wherein the scaling deviation correcting parameter is used for correcting overlong or overlong longitudinal dimension of the printed color layer;

Specifically, step 107 specifically includes steps 1071 to 1076:

step 1071, a first coordinate system is established by taking a preselected first characteristic point as an origin;

among the plurality of first feature points, one feature point is selected as a reference point, that is, an "origin". A new coordinate system is created with the preselected first feature point as the origin. The positions of all other first feature points will be expressed with respect to the origin, so that the positions thereof can be standardized for the convenience of subsequent calculation.

Step 1072, calculating a fourth distance between the preselected first feature point and other first feature points, wherein the other first feature points are feature points except the preselected first feature point in the plurality of first feature points;

The difference in Euclidean distance or other metric between the preselected first feature point and all other first feature points is calculated. Since the points are in the same coordinate system, the distances can measure the relative positions of the feature points with respect to the preselected first feature point.

Step 1073, a second coordinate system is established by taking the corresponding point of the preselected second characteristic point as an origin, wherein the preselected first characteristic point and the preselected second characteristic point are the same characteristic point on the surface of the object;

One of the plurality of second feature points is selected as a reference point, i.e., an "origin". A new coordinate system is created with the preselected second feature point as the origin. The positions of all other second feature points will be represented with respect to the origin for subsequent calculation and comparison.

Step 1074, calculating a fifth distance between a preselected second feature point and other second feature points, wherein the other second feature points are feature points except the preselected second feature point in the plurality of second feature points;

The distance differences between the preselected second feature point and all other second feature points are calculated. These distances reflect the change in position of the other feature points relative to the preselected second feature point.

Step 1075, calculating a second difference value between a fourth distance and a fifth distance corresponding to the same feature point on the surface of the object;

the preselected first feature point and the preselected second feature point are corresponding points on the same object on the object surface. By calculating the difference between the fourth distance (distance in the first coordinate system) and the fifth distance (distance in the second coordinate system) corresponding to the two feature points, the relative scaling difference of the object surface between the two sets of feature points can be reflected.

Step 1076, if the average value of the plurality of second difference values is greater than the fifth threshold value, calculating the scaling deviation correcting parameter by adopting a feedback control algorithm based on the second difference values.

And averaging the second differences corresponding to all the same characteristic points to obtain an integral scaling difference value. And setting a threshold value, and if the average value of the second difference value is larger than the threshold value, indicating that obvious scaling errors exist between the characteristic points on the surface of the object, so that the degree of correction is required. And calculating by using a feedback control algorithm to obtain the final scaling deviation correction parameter. The feedback control algorithm is used to dynamically adjust the parameters. It is achieved by detecting the error (i.e. the second difference) and adjusting the roller speed according to the magnitude of the error until the error is reduced to an acceptable range. The feedback control algorithm is used to calculate the roller speed (i.e., scale the correction parameters).

Alternatively, the feedback control algorithm may be a conventional feedback control algorithm, and this embodiment provides a new feedback control algorithm, as shown in the following mathematical model:

Wherein, Indicating the adjusted drum speed (i.e. scaling deviation correcting parameters),Indicating the current roller speed of the roller,The ratio of the speed adjustment is indicated,The integral of the speed adjustment is represented,A second difference value is indicated and is used to indicate,The duration of the deviation rectifying period is indicated,A differential coefficient representing the speed adjustment is provided,AndRepresenting the dynamic adjustment coefficient associated with the abnormal quantity.Representing the damping coefficient of the system for ensuring stability.A time constant is represented for smoothing the response of the adjustment speed.

By directly correlating the current error (second difference) with a proportionality constantMultiplying to determine the magnitude of the adjustment. Here, theRepresenting if the current abnormal quantityLarger roller speeds require greater adjustment to reduce print pattern errors.

Is to compensate for the historical accumulation of errors by weighting the historical integral terms of the outliers (by coefficientsTo adjust the speed. The function of the integral term is to eliminate errors that exist for a long time. For example, if the printed pattern is always large, the proportional control can only be corrected on the fly, but the integral control can slowly adjust the speed by continuously accumulating the deviations, eventually eliminating these long-term errors. It can help eliminate persistent small errors or systematic offsets.

Based on the rate of change of the error (i.e) To predict future trends in the anomaly and to react in advance when the anomaly changes rapidly. For example, if the rate of change of the abnormal amount is fast, the differential control may appropriately increase the speed adjustment, preventing accumulation of excessive deviation. The differential control can reduce overshoot and oscillation of the system and improve response speed and stability.

This term incorporates an anomalyAnd a factor that decays with timeThe method has the effect of dynamically correcting short-term abnormal quantity, and gradually reducing the adjustment force along with the time. Typically, abnormal amounts may need to respond quickly when they occur, but their effect gradually diminishes over time. Therefore, the damping factor can ensure that the adjustment of the roller speed does not last too long, avoiding overcorrection.The intensity of the dynamic response is controlled.

This term is used for stability adjustment of the system. It suppresses excessive speed fluctuations and abrupt changes by integrating the square of the abnormal-amount change rate (speed change). Specifically, if the abnormal quantity is changed drastically, the damping term increases the speed adjustment force, slows down the system response, and prevents excessive response or oscillation.The intensity of the damping effect is controlled, and the stable response of the system is ensured. The integral form is weighted by the rate of change of the square error, which gives a stronger suppression of drastic changes.

The control strategy targets of the feedback control algorithm are:

Immediate correction-coping with current and future abnormal quantities by proportional and differential control.

Long term adjustment-continuous deviation is eliminated by integral control.

And (3) dynamically responding to the abnormal quantity in time by dynamically adjusting the item, so as to avoid excessive correction.

And the stability of the system is that excessive fluctuation of abnormal quantity change is restrained through a damping item, so that stable adjustment of the system is ensured.

The core principle of the feedback control algorithm is the integrated response and stability. When the system detects anomalies in the transport direction of the printed pattern, the mathematical model adjusts the speed of the roller according to the current anomaly, its history and rate of change. By adjusting the proportion, the integral and the derivative, and combining a dynamic adjustment mechanism and a damping mechanism, the system can quickly and accurately respond to the abnormality, and the phenomenon of over-adjustment or oscillation is avoided.

In this embodiment, accurate positioning and coordinate conversion of the object surface feature points are ensured by establishing the first coordinate system and the second coordinate system with the preselected first feature points and second feature points as origins, respectively. This approach provides a stable reference frame that facilitates further distance calculation and correction of scaling errors. By calculating a fourth distance between the preselected first feature point and the other first feature points and a fifth distance between the preselected second feature point and the other second feature points, the present technique is able to accurately measure the relative positions between the feature points on the surface of the object. The calculation of these distances provides core data for subsequent scaling error analysis. According to the method and the device, the scaling error between the object surface images or objects can be effectively identified by calculating the second difference value between the fourth distance and the fifth distance corresponding to the same feature point on the object surface. The difference analysis method can accurately reflect the size and distribution of the scaling errors according to the relative change among different characteristic points, thereby providing a reliable basis for the subsequent correction calculation. And calculating a scaling deviation correcting parameter through a feedback control algorithm based on the second difference value when the average value of the plurality of second difference values is larger than a fifth threshold value. The feedback mechanism can dynamically adjust the deviation rectifying force, and ensures the automation and the accuracy of the deviation rectifying process. With the change of errors, the feedback algorithm can adjust the deviation rectifying strategy in real time, so that manual intervention is avoided, and the automation and intelligent level of the production process is improved. In the long-time or high-frequency production process, scaling errors of the object surface image may gradually accumulate, and product quality and production stability are affected. According to the technical scheme, through real-time scaling correction, error accumulation can be effectively eliminated, and consistent precision of production of each batch can be ensured, so that the overall production quality is improved.

And step 108, adjusting printing parameters of the roll printer according to the displacement deviation correcting parameters and/or the scaling deviation correcting parameters.

In the embodiment, the image of the object surface of the printed color image layer is acquired in real time and compared with the image of the surface of a standard printed object, so that the pattern deviation can be accurately identified, the delay of manual intervention is avoided, and the accuracy of pattern alignment in the printing process is ensured. According to the invention, manual participation is not needed, the image processing technology is utilized to automatically extract the object surface area and calculate the image difference, so that the manual inspection error is effectively avoided, the production efficiency and the precision are improved, and the manual error rate is reduced. And (3) calculating the distance between the pixel difference value of the image area and the object contour by analyzing the matching of the pixel difference value and the characteristic point, so that the deviation correction parameter is accurately matched. The process can be adjusted in real time in the printing process, ensures that each layer of color of the pattern is accurately aligned, and improves the quality and consistency of multicolor overprinting. The method is suitable for overprinting of different color layers, wherein the printing sequence of each color layer is possibly different, can flexibly adapt to various printing scenes, and ensures that the high-level printing precision can be maintained even in the multicolor printing process. Through timely adjustment printing deviation, the rejection rate caused by overlarge deviation is avoided, and meanwhile, the time cost of manual inspection and adjustment is reduced, so that the overall production efficiency is improved. Because the deviation can be corrected in real time in the printing process, the invention can effectively avoid printing defects such as pattern overlapping, color deviation and the like, ensure high-quality output of each printing period and improve the overall quality and the aesthetic degree of printed articles. In a word, the printing deviation correcting method of the roll printer solves the problems of untimely deviation monitoring, low deviation correcting precision and the like which are common in the traditional method through an intelligent and automatic technical means, and can greatly improve the printing quality and the production efficiency.

Referring to fig. 2, fig. 2 shows a schematic diagram of a printing deviation correcting device of a roll printing machine according to the present invention, and the printing deviation correcting device of the roll printing machine shown in fig. 2 includes:

A first obtaining unit 21, configured to obtain a plurality of color layers of a print pattern and standard print object surface images corresponding to the plurality of color layers, where the plurality of color layers are used for multicolor overprinting to form the print pattern, and the standard print object surface images are standard print images obtained by sequentially overlapping the color layers on a preset position of an object image, where different color layers have different printing orders;

An acquisition unit 22, configured to acquire an object surface image of the printed color layer in real time, and extract an object surface area in the object surface image;

An extracting unit 23 for extracting a first image area of the object surface area and a second image area of a current standard print object surface image, the current standard print object surface image being a standard print object surface image corresponding to the printed color layer;

a first calculating unit 24, configured to calculate a pixel difference value of the same pixel position between the first image area and the second image area, and count the number of pixel positions where the pixel difference value is greater than a first threshold;

A second obtaining unit 25 configured to obtain a plurality of first feature points of the first image area and a plurality of second feature points of the second image area when the number of pixel positions is greater than a second threshold;

A matching unit 26, configured to match a displacement correction parameter according to a first distance between the plurality of first feature points and the object contour, where the displacement correction parameter is used to correct a position deviation in the conveying direction;

A second calculation unit 27, configured to calculate a scaling correction parameter according to the distance differences between the plurality of first feature points and the plurality of second feature points, where the scaling correction parameter is used to correct the overlength or overlength of the longitudinal dimension of the printed color layer;

And the adjusting unit 28 is used for adjusting the printing parameters of the roll printer according to the displacement deviation correcting parameters and/or the scaling deviation correcting parameters.

According to the printing deviation correcting device of the roller printer, provided by the invention, the pattern deviation can be accurately identified by collecting the object surface image of the printed color layer in real time and comparing the object surface image with the standard printed object surface image, so that the delay of manual intervention is avoided, and the accuracy of pattern alignment in the printing process is ensured. According to the invention, manual participation is not needed, the image processing technology is utilized to automatically extract the object surface area and calculate the image difference, so that the manual inspection error is effectively avoided, the production efficiency and the precision are improved, and the manual error rate is reduced. And (3) calculating the distance between the pixel difference value of the image area and the object contour by analyzing the matching of the pixel difference value and the characteristic point, so that the deviation correction parameter is accurately matched. The process can be adjusted in real time in the printing process, ensures that each layer of color of the pattern is accurately aligned, and improves the quality and consistency of multicolor overprinting. The method is suitable for overprinting of different color layers, wherein the printing sequence of each color layer is possibly different, can flexibly adapt to various printing scenes, and ensures that the high-level printing precision can be maintained even in the multicolor printing process. Through timely adjustment printing deviation, the rejection rate caused by overlarge deviation is avoided, and meanwhile, the time cost of manual inspection and adjustment is reduced, so that the overall production efficiency is improved. Because the deviation can be corrected in real time in the printing process, the invention can effectively avoid printing defects such as pattern overlapping, color deviation and the like, ensure high-quality output of each printing period and improve the overall quality and the aesthetic degree of printed articles. In a word, the printing deviation correcting method of the roll printer solves the problems of untimely deviation monitoring, low deviation correcting precision and the like which are common in the traditional method through an intelligent and automatic technical means, and can greatly improve the printing quality and the production efficiency.

Fig. 3 is a schematic view of a roll printing machine according to an embodiment of the present invention. As shown in fig. 3, a roll printer 3 of this embodiment includes a processor 30, a memory 31, a roller system 33, a camera 34, and a computer program 32 stored in the memory 31 and executable on the processor 30, such as a printing correction program for a roll printer. The processor 30, when executing the computer program 32, implements the steps of each of the printing deviation correcting method embodiments of a roll printer described above, such as steps 101 through 108 shown in fig. 1. Or the processor 30, when executing the computer program 32, performs the functions of the units in the above-described device embodiments, for example the functions of the units shown in fig. 2.

By way of example, the computer program 32 may be divided into one or more units, which are stored in the memory 31 and executed by the processor 30 to complete the present invention. The one or more units may be a series of computer program instruction segments capable of performing a specific function for describing the execution of the computer program 32 in the one roll printer 3. For example, the computer program 32 may be partitioned into units having the following specific functions:

Including but not limited to a processor 30 and a memory 31. It will be appreciated by those skilled in the art that fig. 3 is merely an example of one type of roll printer 3 and is not intended to be limiting of one type of roll printer 3, and may include more or fewer components than shown, or may combine certain components, or different components, e.g., the one type of roll printer may also include input and output devices, network access devices, buses, etc.

The Processor 30 may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (DIGITAL SIGNAL Processor, DSP), application SPECIFIC INTEGRATED Circuit (ASIC), off-the-shelf Programmable gate array (Field-Programmable GATE ARRAY, FPGA) or other Programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 31 may be an internal storage unit of the roll squeezer 3, for example, a hard disk or a memory of the roll squeezer 3. The memory 31 may also be an external storage device of the roll printer 3, such as a plug-in hard disk, a smart memory card (SMART MEDIA CARD, SMC), a Secure Digital (SD) card, a flash memory card (FLASH CARD) or the like, which are provided on the roll printer 3. Further, the memory 31 may also include both an internal memory unit and an external memory device of the one roll printer 3. The memory 31 is used for storing the computer program as well as other programs and data as required. The memory 31 may also be used for temporarily storing data that has been output or is to be output.

It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present invention.

It should be noted that, because the content of information interaction and execution process between the above devices/units is based on the same concept as the method embodiment of the present invention, specific functions and technical effects thereof may be referred to in the method embodiment section, and will not be described herein.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules, so as to perform all or part of the functions described above. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, the specific names of the functional units and modules are only for distinguishing from each other, and are not used for limiting the protection scope of the present invention. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.

Embodiments of the present invention also provide a computer readable storage medium storing a computer program which, when executed by a processor, implements steps for implementing the various method embodiments described above.

Embodiments of the present invention provide a computer program product which, when run on a mobile terminal, causes the mobile terminal to perform steps that enable the implementation of the method embodiments described above.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the present invention may implement all or part of the flow of the method of the above embodiments, and may be implemented by a computer program to instruct related hardware, where the computer program may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the computer program may implement the steps of each of the method embodiments described above. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include at least a recording medium, a computer Memory, a Read-Only Memory (ROM), a random-Access Memory (RAM), an electrical carrier signal, a telecommunications signal, and a software distribution medium. Such as a U-disk, removable hard disk, magnetic or optical disk, etc.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/network device and method may be implemented in other manners. For example, the apparatus/network device embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical functional division, and there may be additional divisions in actual implementation, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units.

It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

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

As used in the present description and the appended claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to a detection" depending on the context. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is monitored" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon monitoring a [ described condition or event ]" or "in response to monitoring a [ described condition or event ]".

Furthermore, the terms "first," "second," "third," and the like in the description of the present specification and in the appended claims, are used for distinguishing between descriptions and not necessarily for indicating or implying a relative importance.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the invention. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

The foregoing embodiments are merely illustrative of the technical solutions of the present invention, and not restrictive, and although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that modifications may still be made to the technical solutions described in the foregoing embodiments or equivalent substitutions of some technical features thereof, and that such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The printing deviation rectifying method of the roller printer is characterized by comprising the following steps of:

collecting an object surface image of the printed color image layer in real time;

Acquiring surface color information of a transmission structure;

identifying a plurality of first feature points in the object image;

Rotating the object image to the direction corresponding to the standard direction vector based on the included angle to obtain an object surface area;

2. The method of printing offset correction for a roll printer of claim 1, wherein the step of extracting a first image area of the object surface area and a second image area of the current standard printed object surface image comprises:

3. The method of printing offset correction for a roll printer of claim 1, wherein said step of identifying a plurality of first feature points in said image of said object comprises:

4. The printing deviation correcting method of a roll printer according to claim 3, wherein the step of calculating a similarity between the rectangular pixel area and the standard reference map comprises:

5. The method of printing offset correction for a roll printer of claim 1, wherein the step of matching the displacement correction parameters based on a first distance between the plurality of first feature points and the contour of the object comprises:

calculating a first center position of the surface profile of the object;

Calculating second center positions of the plurality of first feature points;

6. The printing deviation rectifying method of roll printer of claim 1, wherein said step of calculating a scaling deviation rectifying parameter based on the distance differences between the plurality of first feature points and the plurality of second feature points comprises:

7. The utility model provides a printing deviation correcting device of roll mark machine which characterized in that, printing deviation correcting device of roll mark machine includes:

The device comprises an acquisition unit, an object image acquisition unit, a calculation unit and an object surface area acquisition unit, wherein the acquisition unit is used for acquiring an object surface image of a printed color image layer in real time, acquiring surface color information of a transmission structure, removing an image area corresponding to the surface color information in the object surface image to obtain an object image, identifying a plurality of first feature points in the object image, calculating a current direction vector formed by two target first feature points, and acquiring a standard direction vector of the target first feature points, wherein the standard direction vector refers to a direction vector formed by two target first feature points when the object surface is in a correct direction, the target first feature points refer to first feature points which are preselected for direction correction, calculating an included angle between the current direction vector and the standard direction vector, and rotating the object image to a direction corresponding to the standard direction vector based on the included angle to obtain the object surface area;

The device comprises an extraction unit, a display unit and a display unit, wherein the extraction unit is used for extracting a first image area of an object surface area and a second image area of a current standard printed object surface image, the current standard printed object surface image is a standard printed object surface image corresponding to a printed color image layer, the first image area is a part extracted from an acquired actual printed image and represents a printed area of an object;

8. A roll printer comprising a roller system, a camera, a memory, a processor, and a printing correction program of the roll printer stored on the memory and operable on the processor, the printing correction program of the roll printer being configured to implement the steps of the printing correction method of the roll printer according to any one of claims 1 to 6.

9. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps in the printing offset method of a roll printer according to any one of claims 1 to 6.