Surface quality visual inspection system for cigarette packaging paper presswork

Abstract

The invention discloses a visual inspection system for the surface quality of a cigarette packaging paper printed matter. The visual inspection system comprises an image acquisition module, a color quality analysis module, an area quality analysis module, an ink pollution analysis module, a character quality analysis module and a printing quality analysis module, according to the method, the color, the ink pollution, the characters, the printing position and the area of the cigarette packaging paper presswork are analyzed to obtain a color quality index, an area quality index, an ink pollution index and a character quality index, and the presswork is correspondingly processed according to the indexes of the presswork to obtain corresponding grades; and finally, according to the four grades of the current printed matter, the printed matter is divided into a qualified product, an unqualified product and a to-be-analyzed product, four indexes of the to-be-analyzed product are analyzed, a printing quality index is obtained, and the to-be-analyzed product is correspondingly processed according to the specific numerical value of the printing index.

Description

Technical Field

[0001] The invention relates to the field of printed matter quality detection, and in particular to a surface quality visual detection system for cigarette packaging paper printed matter. Background Art

[0002] In the cigarette production industry, the printing quality of packaging paper is of vital importance. Cigarette packaging paper not only protects cigarette products, but also serves as an important medium for brand image display. With consumers' increasing requirements for product quality and intensified market competition, cigarette companies need to ensure that the quality of packaging paper printing reaches extremely high standards.

[0003] Traditional manual inspection methods have problems such as low efficiency, strong subjectivity, and easy to miss inspections due to fatigue when facing large-scale production; and some traditional mechanical inspection methods can only detect one or several specific quality problems, such as only detecting color deviation or only focusing on pattern integrity. The inspection aspect is single and cannot achieve comprehensive inspection of cigarette packaging paper printing;

[0004] With the development of computer vision technology, high-resolution imaging devices (such as industrial cameras) can obtain very fine images of the surface of cigarette packaging paper prints. These images can clearly show color details, pattern textures, and text features, etc., providing a good data basis for accurately detecting surface quality problems of cigarette packaging paper prints.

[0005] Therefore, a surface quality visual inspection system for printed cigarette packaging paper is introduced. Summary of the invention

[0006] In view of this, the present invention provides a surface quality visual inspection system for cigarette packaging paper prints to solve the problems raised by the above background technology.

[0007] The purpose of the present invention can be achieved by the following technical solution: A surface quality visual inspection system for cigarette packaging paper printed products, comprising:

[0008] Image acquisition module: Set up LED array light source according to the material, color and surrounding environment of the detected cigarette packaging paper print, build a light source environment, use industrial camera to obtain the surface image of cigarette packaging paper print, and send the surface image of cigarette packaging paper print to text quality analysis module, color quality analysis module, area quality analysis module and ink pollution analysis module;

[0009] Color quality analysis module: used to divide the cigarette packaging paper printed products into regions and analyze the color quality of each divided region to obtain the color quality index SC; and to process the current cigarette packaging paper printed products accordingly and determine the color rating according to the specific value of the color quality index SC;

[0010] Area quality analysis module: used to analyze the area and position of each area of ​​the cigarette packaging paper print, so as to obtain the area quality index MJ; and to process the current cigarette packaging paper print accordingly and determine the area rating according to the specific value of the area quality index MJ;

[0011] Ink pollution analysis module: used to analyze the ink pollution of cigarette packaging paper prints, so as to obtain the ink pollution index YM; and to process the current cigarette packaging paper prints accordingly and determine the ink rating according to the specific value of the ink pollution index YM;

[0012] Text quality analysis module: used to analyze the text quality of cigarette packaging paper prints, thereby obtaining a text quality index WZ; and to process the current cigarette packaging paper prints accordingly and determine the text rating according to the specific value of the text quality index WZ;

[0013] Printing quality analysis module: used to analyze the four indexes and ratings received and process the cigarette packaging paper prints accordingly.

[0014] Furthermore, the specific processing steps of the color quality analysis module are:

[0015] A1: Preprocess the surface image of the cigarette packaging paper print obtained, divide the surface image of the cigarette packaging paper print into various regions; establish a four-color channel histogram of the corresponding region on each divided region, where the four colors refer to cyan, magenta, yellow and black; and perform the same region division and histogram establishment on the standard style image of the cigarette packaging paper print;

[0016] A2: For the histogram of each channel in each region of the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper, only the number of pixels or the frequency corresponding to the color intensity value is retained, so as to obtain the line graph of each channel in each region of the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper, and align the line graphs corresponding to the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper in the same region and the same channel to the same coordinate system;

[0017] A3: Count the number of overlapping points of the two line graphs, subtract the number of overlapping points from 255, and get the number of heterochromaticity Q1. At the same time, connect the two starting points and the two end points of the two line graphs to obtain the area enclosed by the two line graphs, which is recorded as the heterochromaticity area Q2. After normalizing the number of heterochromaticity Q1 and the heterochromaticity area Q2, they are inserted into the formula: QY = Q1*d1+Q2*d2 to obtain the color difference index QY, where d1 and d2 are the weight influence factors corresponding to the number of heterochromaticity Q1 and the heterochromaticity area Q2 respectively.

[0018] A4: The four-color channel histograms corresponding to the surface image of the cigarette packaging paper print and the standard style image of the cigarette packaging paper print in each area are processed in step A3 above, so as to obtain the color difference index corresponding to each channel of each area, and the average value of the four-color channel color difference index QY of each area is taken to obtain the color evaluation index of each area; each weight influence factor corresponding to each area is preset, and the color evaluation index of each area is multiplied by the corresponding weight factor to obtain the color quality index SC of the surface image of the cigarette packaging paper print;

[0019] A5: Determine the color quality index threshold according to the quality requirements of the current batch of cigarette packaging paper prints. If the color quality index SC is higher than the preset color quality index threshold, the color quality of the current cigarette packaging paper prints is judged to be unqualified; otherwise, the color quality is qualified and the color rating is recorded as A;

[0020] A6: For cigarette packaging paper printed products with unqualified colors, the color quality index threshold is subtracted from the color quality index SC to obtain the color quality difference. The color quality difference threshold is preset. If the color quality difference is greater than the preset color quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the color rating is recorded as B;

[0021] A7: Send the color quality index SC and color rating to the printing analysis module.

[0022] Furthermore, the specific processing steps of the area quality analysis module are:

[0023] D1: Using the surface image of the cigarette packaging paper print obtained in step A1 and each area of ​​the standard style image of the cigarette packaging paper print, number each area and use QY i The numbering of each area of ​​the surface image of the cigarette packaging paper print is used The numbering of each area of ​​the standard style image of the cigarette packaging paper print, i = 1, 2...n, n represents the total number of areas after division; the lower left corner of the cigarette packaging paper print is recorded as the marking point, a rectangular coordinate system is established, the area numbered QY1 is selected, a point on the edge of the area is randomly selected, recorded as the target point, the target point is connected with the marking point to form a line segment, the length of the line segment is obtained, recorded as the target distance, the angle between the line segment and the horizontal edge of the print is obtained, recorded as the target angle, the selected surface image area of ​​the cigarette packaging paper print is placed in the rectangular coordinate system, the target point is connected to the coordinate origin, and the selected surface image area of ​​the cigarette packaging paper print is fixed to the coordinate system according to the target distance and the target angle; at the same time, the numbered The same operation is performed on the area corresponding to QY1 and The corresponding areas correspond to the same rectangular coordinate system;

[0024] D2: Get the area and value corresponding to QY1 in the rectangular coordinate system The overlapping area of ​​the corresponding regions is recorded as the correct area, and the The area of ​​the corresponding region is Subtract the correct area from the area of ​​the corresponding region to obtain the error area, and divide the error area by The area of ​​the corresponding region is used to obtain the position error rate;

[0025] D3: Get the area of ​​the region corresponding to QY1, using the formula: Thus, the area error rate MJ is obtained, where It is the allowable area error of the area numbered QY1;

[0026] D4: preset the weighted influence factors corresponding to the position error rate and the area error rate MJ, multiply the position error rate and the area error rate MJ by the corresponding weighted influence factors and then sum them up to obtain the comprehensive area error index of the area numbered QY1;

[0027] D5: performing the above-mentioned operations D1-D4 on each area of ​​the divided surface image of the cigarette packaging paper print, thereby obtaining a comprehensive area error index of each area on the surface image of the cigarette packaging paper print, presetting a weight influence factor of each area on the surface image of the cigarette packaging paper print, and multiplying the comprehensive area error index of each area on the surface image of the cigarette packaging paper print by the corresponding weight influence factor, thereby obtaining an area quality index MJ of the surface image of the cigarette packaging paper print;

[0028] D6: Determine the area quality index threshold according to the quality requirements of the current batch of cigarette packaging paper printed products. If the area quality index MJ is higher than the preset area quality index threshold, the area quality of the current cigarette packaging paper printed products is judged to be unqualified. Otherwise, the area quality is qualified and the area rating is recorded as A.

[0029] D7: For cigarette packaging paper printed products with unqualified area quality, the area quality index MJ is subtracted from the area quality index threshold to obtain the area quality difference. The area quality difference threshold is preset. If the area quality difference is greater than the preset area quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the area rating is recorded as B;

[0030] D8: Send the area quality index and area rating to the printing analysis module.

[0031] Furthermore, the specific processing steps of the ink contamination analysis module are:

[0032] R1: Use color analysis and edge detection algorithms to mark the ink area pollution on the surface image of the cigarette packaging paper print, associate the pollution area marked by color analysis with the pollution boundary obtained by edge detection, so as to obtain the ink pollution area on the surface image of the cigarette packaging paper print, and obtain the area of ​​each ink pollution area and the surface image area of ​​the cigarette packaging paper print where it is located;

[0033] R2: If an ink contaminated area passes through multiple cigarette packaging paper printed product surface image areas, then the area of ​​the ink area on each cigarette packaging paper printed product surface image area is obtained, recorded as the zone area, and the zone area is divided by the area of ​​the ink contaminated area to obtain the contamination ratio of the ink contaminated area on each cigarette packaging paper printed product surface image area, and the contamination ratio is multiplied by the weight influence factor of the corresponding cigarette packaging paper printed product surface image area to obtain the weight influence factor of the ink area; if the ink contaminated area only passes through one cigarette packaging paper printed product surface image area, the weight influence factor of the corresponding cigarette packaging paper printed product surface image area is used as the weight influence factor of the ink area;

[0034] R3: Obtain the area of ​​each ink contaminated area and the corresponding weight influence factor, and multiply the area of ​​the ink contaminated area by the corresponding weight influence factor to obtain the ink contamination index YM;

[0035] R4: Determine the ink contamination index threshold value according to the quality requirements of the current batch of cigarette packaging paper printed products. If the ink contamination index MJ is higher than the preset ink contamination index threshold value, the ink quality of the current cigarette packaging paper printed products is judged to be unqualified. Otherwise, the ink quality is qualified and the ink rating is recorded as A.

[0036] R5: For cigarette packaging paper printed products with unqualified ink quality, the ink pollution index YM is subtracted from the ink pollution index threshold to obtain the ink quality difference. The ink quality difference threshold is preset. If the ink quality difference is greater than the preset ink quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the ink rating is recorded as B;

[0037] R6: Send the ink contamination index YM and ink rating to the printing analysis module.

[0038] Furthermore, the specific processing steps of the text quality analysis module are:

[0039] W1: Use image analysis software to locate the text part of the surface image of the cigarette packaging paper print. For each word, obtain the top and bottom parts of the image and draw two horizontal lines; obtain the left and right parts of the image and draw two vertical lines. The four lines will enclose a rectangular closed area. The area of ​​the rectangular closed area is used as the occupied area F1 of the corresponding word. Obtain the standard occupied area F2 of the corresponding word from the standard style image of the cigarette packaging paper print, using the formula: Obtain the size score WZF of the corresponding text; take the average of all the text size scores as the comprehensive score CC of the text size of the cigarette packaging paper print;

[0040] W2: Use image analysis software to generate edge strength images for text, obtain pixel values ​​of all points on the text edge as the edge strength of the corresponding points, use mean formula and standard deviation formula to calculate the strength of the edges of all points of the text, and use the obtained values ​​as the text mean and text wave value respectively. Divide the text wave value by the text mean to obtain the fuzzy index of the text; take the mean of all text fuzzy indexes as the comprehensive fuzzy index MH of the text printed on cigarette packaging paper;

[0041] W3: using image analysis software to locate each text area on the surface image of the cigarette packaging paper print, and obtain the comprehensive text spacing index JG of the cigarette packaging paper print;

[0042] W4: After normalizing the text size comprehensive score CC, text fuzzy comprehensive index MH and comprehensive text spacing index JG of the printed matter on cigarette packaging paper, they are inserted into the formula: The text quality index WZ is obtained, where v1, v2 and v3 are weighted influencing factors corresponding to the comprehensive score CC of the text size, the comprehensive text spacing index JG and the comprehensive text fuzziness index MH of the printed matter of cigarette packaging paper respectively;

[0043] W5: Determine the text quality index threshold according to the quality requirements of the current batch of cigarette packaging paper prints. If the text quality index WZ is lower than the preset text quality index threshold, the text quality of the current cigarette packaging paper prints is judged to be unqualified; otherwise, the text quality is qualified and the text rating is recorded as A;

[0044] W6: For cigarette packaging paper printed products with unqualified text quality, the text quality index WZ is subtracted from the text quality index threshold to obtain the text quality difference. The text quality difference threshold is preset. If the text quality difference is greater than the preset ink text quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the text rating is recorded as B;

[0045] W7: Send the text quality index WZ and text rating to the printing analysis module.

[0046] Furthermore, the specific steps of obtaining the comprehensive text spacing index JG of the cigarette packaging paper are as follows:

[0047] W3-1: For two adjacent characters, obtain the rightmost point of the left character and the leftmost point of the right character, calculate the horizontal distance between the two points, and use it as the distance between the two adjacent characters; obtain the distances between all adjacent characters in the area, thereby obtaining a character distance set; obtain the standard character distance of the area from the standard style image of the cigarette packaging paper print, preset an allowable error according to the quality requirements of the current batch of cigarette packaging paper prints, calculate the manufacturing interval, use the standard character distance of the area plus the allowable error as the maximum value of the manufacturing interval, and use the standard character distance of the area minus the allowable error as the minimum value of the manufacturing interval; extract the data that is not in the manufacturing interval from the character distance set, and form a new set of the obtained data as the error set;

[0048] W3-2: For data in the error set, if it is greater than the maximum value of the manufacturing interval, the maximum value of the manufacturing interval is subtracted from the data, and the result is used as the error difference of the data; if it is less than the minimum value of the manufacturing interval, the data is subtracted from the minimum value of the manufacturing interval, and the result is used as the error difference of the data; preset error difference intervals, set each error difference interval to correspond to each error score, match the error difference interval corresponding to the error difference of the data in the error set, so as to obtain the error score of each data in the error set; take the average of all error scores as the distance error score of the area;

[0049] W3-3: Perform operations from W3-1 to W3-2 on each text area to obtain the distance error score corresponding to each text area, and take the average of the distance error scores of each area as the comprehensive text spacing index JG of the cigarette packaging paper print.

[0050] Furthermore, the specific processing steps of the quality analysis module are:

[0051] Arrange the four ratings obtained in the order of color, area, ink and text to obtain a comprehensive rating. If the comprehensive rating is AAAA, the quality of the current cigarette packaging paper print is determined to be qualified; if the comprehensive rating contains two or more Bs, the quality of the current cigarette packaging paper print is determined to be unqualified, and the current cigarette packaging paper print is stored in the warehouse and waits for the next production quality requirement to be reduced before being shipped out; if the number of Bs in the comprehensive rating is less than or equal to 2, the current cigarette packaging paper print is determined to be a product to be analyzed, and the four indexes of the product to be analyzed are analyzed as follows:

[0052] The text quality index WZ, color quality index SC, area quality index MJ and ink contamination index YM of the product to be analyzed are normalized and then entered into the formula: Get the printing quality index YSZ, where λ1 、 λ2 、 λ3 and λ4 are the weighted influencing factors corresponding to the text quality index WZ, the color quality index SC, the area quality index MJ and the ink contamination index YM respectively;

[0053] A printing quality index threshold is preset according to the quality requirements of the currently produced cigarette packaging paper printed product. If the quality index YSZ of the cigarette packaging paper printed product is lower than the preset printing quality index threshold, it is determined that the quality of the current cigarette packaging paper printed product is unqualified; otherwise, the quality of the cigarette packaging paper printed product is qualified;

[0054] For unqualified cigarette packaging paper printed materials, the preset printing quality index threshold is subtracted from the printing quality index YSZ to obtain the index difference. If the index difference is less than the preset index difference threshold, the current cigarette packaging paper printed materials are stored in the warehouse and will not be shipped out until the next production quality requirement is reduced; if the index difference is greater than the preset index difference threshold, the current cigarette packaging paper printed materials are directly scrapped.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The present invention pre-processes the acquired image, uses edge detection, morphological operation, boundary tracking and other algorithms to accurately divide the image area, then establishes a four-color channel histogram based on the area, calculates the color difference index and color evaluation index through careful comparison and analysis of the difference with the standard style image, and finally obtains the color quality index. Compared with the traditional method, it can analyze the color quality more accurately and effectively detect problems such as slight color deviation;

[0057] The present invention calculates the overlap area and the error area, and then obtains the area error rate, the comprehensive area error index and the area quality index, which is more accurate in detecting quality problems in terms of area and position, and overcomes the shortcomings of the prior art that the accuracy is limited and it is difficult to accurately detect such problems.

[0058] The present invention uses color analysis and edge detection algorithm to associate marks, accurately obtains the ink contamination area, considers its situation in different image areas to determine the weight influence factor, and finally accurately obtains the ink contamination index, which makes the detection of ink contamination more detailed and reliable;

[0059] The present invention starts from multiple angles such as text size, blur degree, text spacing, etc., locates text through professional image analysis software and performs quantitative analysis, such as calculating the occupied area and edge strength of text, and finally obtains the text quality index. Compared with traditional detection methods, it can measure the text quality more comprehensively and accurately.

[0060] The present invention introduces a rating system for color, area, ink and text to obtain a comprehensive rating of cigarette packaging paper prints, analyzes the comprehensive rating to distinguish qualified products, unqualified products and products to be analyzed; comprehensively analyzes the four indexes of the products to be analyzed to obtain the printing quality index of the products to be analyzed, and according to the specific values ​​of the printing index, the products to be analyzed are divided into qualified products, scrapped products and products stored in a warehouse and released when the quality requirements are reduced next time, thereby realizing comprehensive analysis and meticulous processing of cigarette packaging paper prints. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Further details, features and advantages of the present application are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0062] Figure 1 It is a principle block diagram of the present invention. DETAILED DESCRIPTION

[0063] Several embodiments of the present application will be described in more detail below with reference to the accompanying drawings so that those skilled in the art can implement the present application. The present application can be embodied in many different forms and purposes and should not be limited to the embodiments described herein. These embodiments are provided to make the present application comprehensive and complete, and to fully convey the scope of the present application to those skilled in the art. The embodiments do not limit the present application.

[0064] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and / or this specification, and will not be interpreted in an idealized or overly formal sense, unless explicitly defined as such herein.

[0065] See also Figure 1 As shown, a surface quality visual inspection system for printed cigarette packaging paper includes: an image acquisition module, a color quality analysis module, an area quality analysis module, an ink contamination analysis module, a text quality analysis module and a printing quality analysis module;

[0066] Image acquisition module: Set up the LED array light source according to the material, color and surrounding environment of the detected cigarette packaging paper prints, build a light source environment, use an industrial camera to obtain the surface image of the cigarette packaging paper prints, and send the surface image of the cigarette packaging paper prints to the text quality analysis module, color quality analysis module, area quality analysis module and ink contamination analysis module.

[0067] Color quality analysis module: used to divide the cigarette packaging paper printed products into regions and analyze the color quality of each divided region to obtain the color quality index SC; and to process the current cigarette packaging paper printed products accordingly and determine the color rating according to the specific value of the color quality index SC;

[0068] A1: Preprocess the obtained surface image of cigarette packaging paper prints, including enhancement, denoising and normalization. Use edge detection algorithm to locate the boundary of each area of ​​the surface image of cigarette packaging paper prints, use morphological operations to connect broken edges or remove isolated edge points, and morphological operations include corrosion and expansion. Use boundary tracking algorithm to fill the internal area from a point on the edge, so as to divide the surface image of cigarette packaging paper prints into various areas; establish a four-color channel histogram of the corresponding area on each divided area, and the four colors refer to cyan, magenta, yellow and black; and perform the same area division and histogram establishment on the standard style image of cigarette packaging paper prints;

[0069] A2: For the histogram of each channel in each region of the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper, only the number of pixels or the frequency corresponding to the color intensity value is retained, so as to obtain the line graph of each channel in each region of the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper, and align the line graphs corresponding to the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper in the same region and the same channel to the same coordinate system;

[0070] A3: Count the number of overlapping points of the two line graphs, subtract the number of overlapping points from 255, and get the number of heterochromaticity Q1. At the same time, connect the two starting points and the two end points of the two line graphs to obtain the area enclosed by the two line graphs, which is recorded as the heterochromaticity area Q2. After normalizing the number of heterochromaticity Q1 and the heterochromaticity area Q2, they are inserted into the formula: QY = Q1*d1+Q2*d2 to obtain the color difference index QY, where d1 and d2 are the weight influence factors corresponding to the number of heterochromaticity Q1 and the heterochromaticity area Q2 respectively.

[0071] A4: The four-color channel histograms corresponding to the surface image of the cigarette packaging paper print and the standard style image of the cigarette packaging paper print in each area are processed in step A3 above, so as to obtain the color difference index corresponding to each channel of each area, and the average value of the four-color channel color difference index QY of each area is taken to obtain the color evaluation index of each area; each weight influence factor corresponding to each area is preset, and the color evaluation index of each area is multiplied by the corresponding weight factor to obtain the color quality index SC of the surface image of the cigarette packaging paper print;

[0072] The same processing is performed on each channel in each area to obtain the color difference index, and then the color evaluation index is calculated. The color quality index is obtained by combining the weight factor, which comprehensively considers the color conditions of different areas of the printed product and realizes an accurate evaluation of the overall color quality.

[0073] A5: Determine the color quality index threshold according to the quality requirements of the current batch of cigarette packaging paper prints. If the color quality index SC is higher than the preset color quality index threshold, the color quality of the current cigarette packaging paper prints is judged to be unqualified; otherwise, the color quality is qualified and the color rating is recorded as A;

[0074] A6: For cigarette packaging paper printed products with unqualified colors, the color quality index threshold is subtracted from the color quality index SC to obtain the color quality difference. The color quality difference threshold is preset. If the color quality difference is greater than the preset color quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the color rating is recorded as B;

[0075] Based on the comparison between the color quality index and the color quality index threshold, as well as the comparison between the color quality difference and the color quality difference threshold, the color quality of printed products is graded and determined, providing a clear basis for subsequent decision-making and helping to deal with products of different quality conditions in a targeted manner;

[0076] A7: Send the color quality index SC and color rating to the printing analysis module.

[0077] Area quality analysis module: used to analyze the area and position of each area of ​​the cigarette packaging paper print, so as to obtain the area quality index MJ; and to process the current cigarette packaging paper print accordingly and determine the area rating according to the specific value of the area quality index MJ;

[0078] D1: Using the surface image of the cigarette packaging paper print obtained in step A1 and each area of ​​the standard style image of the cigarette packaging paper print, number each area and use QY i The numbering of each area of ​​the surface image of the cigarette packaging paper print is done in QY i 标准The numbering of each area of ​​the standard style image of the cigarette packaging paper print, i = 1, 2...n, n represents the total number of areas after division; the lower left corner of the cigarette packaging paper print is recorded as the marking point, a rectangular coordinate system is established, the area numbered QY1 is selected, a point on the edge of the area is randomly selected, recorded as the target point, the target point is connected with the marking point to form a line segment, the length of the line segment is obtained, recorded as the target distance, the angle between the line segment and the horizontal edge of the print is obtained, recorded as the target angle, the selected surface image area of ​​the cigarette packaging paper print is placed in the rectangular coordinate system, the target point is connected to the coordinate origin, and the selected surface image area of ​​the cigarette packaging paper print is fixed to the coordinate system according to the target distance and the target angle; at the same time, the numbered The same operation is performed on the area corresponding to QY1 and The corresponding areas correspond to the same rectangular coordinate system;

[0079] By selecting target points at the edge of a specific area, measuring the target distance and target angle, and fixing the area in the coordinate system based on these parameters, the position of each area in the coordinate system can be accurately determined;

[0080] D2: Get the area and value corresponding to QY1 in the rectangular coordinate system The overlapping area of ​​the corresponding regions is recorded as the correct area, and the The area of ​​the corresponding region is Subtract the correct area from the area of ​​the corresponding region to obtain the error area, and divide the error area by The area of ​​the corresponding region is used to obtain the position error rate;

[0081] D3: Get the area of ​​the region corresponding to QY1, using the formula: Thus, the area error rate MJ is obtained, where It is the allowable area error of the area numbered QY1;

[0082] D4: preset the weighted influence factors corresponding to the position error rate and the area error rate MJ, multiply the position error rate and the area error rate MJ by the corresponding weighted influence factors and then sum them up to obtain the comprehensive area error index of the area numbered QY1;

[0083] D5: performing the above-mentioned operations D1-D4 on each area of ​​the divided surface image of the cigarette packaging paper print, thereby obtaining a comprehensive area error index of each area on the surface image of the cigarette packaging paper print, presetting a weight influence factor of each area on the surface image of the cigarette packaging paper print, and multiplying the comprehensive area error index of each area on the surface image of the cigarette packaging paper print by the corresponding weight influence factor, thereby obtaining an area quality index MJ of the surface image of the cigarette packaging paper print;

[0084] D6: Determine the area quality index threshold according to the quality requirements of the current batch of cigarette packaging paper printed products. If the area quality index MJ is higher than the preset area quality index threshold, the area quality of the current cigarette packaging paper printed products is judged to be unqualified. Otherwise, the area quality is qualified and the area rating is recorded as A.

[0085] D7: For cigarette packaging paper printed products with unqualified area quality, the area quality index MJ is subtracted from the area quality index threshold to obtain the area quality difference. The area quality difference threshold is preset. If the area quality difference is greater than the preset area quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the area rating is recorded as B;

[0086] D8: Send the area quality index and area rating to the printing analysis module.

[0087] Ink pollution analysis module: used to analyze the ink pollution of cigarette packaging paper prints, so as to obtain the ink pollution index YM; and to process the current cigarette packaging paper prints accordingly and determine the ink rating according to the specific value of the ink pollution index YM;

[0088] R1: Use color analysis and edge detection algorithms to mark the ink area pollution on the surface image of the cigarette packaging paper print, associate the pollution area marked by color analysis with the pollution boundary obtained by edge detection, so as to obtain the ink pollution area on the surface image of the cigarette packaging paper print, and obtain the area of ​​each ink pollution area and the surface image area of ​​the cigarette packaging paper print where it is located;

[0089] By marking and associating the ink contaminated areas through color analysis and edge detection algorithms, the ink contaminated areas on the printed surface of cigarette packaging paper can be accurately identified, and their area and image region can be clearly identified, providing an accurate data basis for subsequent analysis;

[0090] R2: If an ink contaminated area passes through multiple cigarette packaging paper printed product surface image areas, then the area of ​​the ink area on each cigarette packaging paper printed product surface image area is obtained, recorded as the zone area, and the zone area is divided by the area of ​​the ink contaminated area to obtain the contamination ratio of the ink contaminated area on each cigarette packaging paper printed product surface image area, and the contamination ratio is multiplied by the weight influence factor of the corresponding cigarette packaging paper printed product surface image area to obtain the weight influence factor of the ink area; if the ink contaminated area only passes through one cigarette packaging paper printed product surface image area, the weight influence factor of the corresponding cigarette packaging paper printed product surface image area is used as the weight influence factor of the ink area;

[0091] In view of the complex situation that the ink contaminated area spans across different image areas, the weight influence factor of the ink area is determined by calculating the contamination ratio and combining it with the corresponding area weight factor; for the case where it only passes through one area, the corresponding area weight factor is directly used; this method fully considers the importance differences of different areas, making the evaluation results more reasonable and scientific;

[0092] R3: Obtain the area of ​​each ink contaminated area and the corresponding weight influence factor, and multiply the area of ​​the ink contaminated area by the corresponding weight influence factor to obtain the ink contamination index YM;

[0093] R4: Determine the ink contamination index threshold value according to the quality requirements of the current batch of cigarette packaging paper printed products. If the ink contamination index MJ is higher than the preset ink contamination index threshold value, the ink quality of the current cigarette packaging paper printed products is judged to be unqualified. Otherwise, the ink quality is qualified and the ink rating is recorded as A.

[0094] R5: For cigarette packaging paper printed products with unqualified ink quality, the ink pollution index YM is subtracted from the ink pollution index threshold to obtain the ink quality difference. The ink quality difference threshold is preset. If the ink quality difference is greater than the preset ink quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the ink rating is recorded as B;

[0095] R6: Send the ink contamination index YM and ink rating to the printing analysis module.

[0096] Text quality analysis module: used to analyze the text quality of cigarette packaging paper prints, thereby obtaining a text quality index WZ; and to process the current cigarette packaging paper prints accordingly and determine the text rating according to the specific value of the text quality index WZ;

[0097] W1: Use image analysis software to locate the text part of the surface image of the cigarette packaging paper print. For each word, obtain the top and bottom parts of the image and draw two horizontal lines; obtain the left and right parts of the image and draw two vertical lines. The four lines will enclose a rectangular closed area. The area of ​​the rectangular closed area is used as the occupied area F1 of the corresponding word. Obtain the standard occupied area F2 of the corresponding word from the standard style image of the cigarette packaging paper print, using the formula: Obtain the size score WZF of the corresponding text; take the average of all the text size scores as the comprehensive score CC of the text size of the cigarette packaging paper print;

[0098] W2: Use image analysis software to generate edge strength images for text, obtain pixel values ​​of all points on the text edge as the edge strength of the corresponding points, use mean formula and standard deviation formula to calculate the strength of the edges of all points of the text, and use the obtained values ​​as the text mean and text wave value respectively. Divide the text wave value by the text mean to obtain the fuzzy index of the text; take the mean of all text fuzzy indexes as the comprehensive fuzzy index MH of the text printed on cigarette packaging paper;

[0099] W3: Use image analysis software to locate each text area on the surface image of the cigarette packaging paper print product, and obtain the comprehensive text spacing index JG of the cigarette packaging paper print product;

[0100] W3-1: For two adjacent characters, obtain the rightmost point of the left character and the leftmost point of the right character, calculate the horizontal distance between the two points, and use it as the distance between the two adjacent characters; obtain the distances between all adjacent characters in the area, thereby obtaining a character distance set; obtain the standard character distance of the area from the standard style image of the cigarette packaging paper print, preset an allowable error according to the quality requirements of the current batch of cigarette packaging paper prints, calculate the manufacturing interval, use the standard character distance of the area plus the allowable error as the maximum value of the manufacturing interval, and use the standard character distance of the area minus the allowable error as the minimum value of the manufacturing interval; extract the data that is not in the manufacturing interval from the character distance set, and form a new set of the obtained data as the error set;

[0101] W3-2: For data in the error set, if it is greater than the maximum value of the manufacturing interval, the maximum value of the manufacturing interval is subtracted from the data, and the result is used as the error difference of the data; if it is less than the minimum value of the manufacturing interval, the data is subtracted from the minimum value of the manufacturing interval, and the result is used as the error difference of the data; preset error difference intervals, set each error difference interval to correspond to each error score, the larger the error difference, the lower the error score, match the error difference interval corresponding to the error difference of the data in the error set, so as to obtain the error score of each data in the error set; take the average of all error scores as the distance error score of the area;

[0102] W3-3: Perform operations from W3-1 to W3-2 on each text area to obtain the distance error score corresponding to each text area, and take the average of the distance error scores of each area as the comprehensive text spacing index JG of the cigarette packaging paper print.

[0103] W4: After normalizing the text size comprehensive score CC, text fuzzy comprehensive index MH and comprehensive text spacing index JG of the printed matter on cigarette packaging paper, they are inserted into the formula: The text quality index WZ is obtained, where v1, v2 and v3 are weighted influencing factors corresponding to the comprehensive score CC of the text size, the comprehensive text spacing index JG and the comprehensive text fuzziness index MH of the printed matter of cigarette packaging paper respectively;

[0104] After normalizing the comprehensive score of text size, comprehensive index of text fuzziness and comprehensive text spacing index, the text quality index was calculated by combining their respective weighted influencing factors. Taking multiple dimensions into consideration, the text quality of printed materials on cigarette packaging was comprehensively and systematically evaluated.

[0105] W5: Determine the text quality index threshold according to the quality requirements of the current batch of cigarette packaging paper prints. If the text quality index WZ is lower than the preset text quality index threshold, the text quality of the current cigarette packaging paper prints is judged to be unqualified; otherwise, the text quality is qualified and the text rating is recorded as A;

[0106] W6: For cigarette packaging paper printed products with unqualified text quality, the text quality index WZ is subtracted from the text quality index threshold to obtain the text quality difference. The text quality difference threshold is preset. If the text quality difference is greater than the preset ink text quality difference threshold, the current cigarette packaging paper printed product is scrapped; otherwise, the text rating is recorded as B;

[0107] W7: Send the text quality index WZ and text rating to the printing analysis module.

[0108] Printing quality analysis module: used to analyze the four indexes and ratings received and process the cigarette packaging paper prints accordingly;

[0109] Arrange the four ratings obtained in the order of color, area, ink and text to obtain a comprehensive rating. If the comprehensive rating is AAAA, the quality of the current cigarette packaging paper print is determined to be qualified; if the comprehensive rating contains two or more Bs, the quality of the current cigarette packaging paper print is determined to be unqualified, and the current cigarette packaging paper print is stored in the warehouse and waits for the next production quality requirement to be reduced before being shipped out; if the number of Bs in the comprehensive rating is less than or equal to 2, the current cigarette packaging paper print is determined to be a product to be analyzed, and the four indexes of the product to be analyzed are analyzed as follows:

[0110] Different judgments and treatments are made according to the comprehensive ratings. Qualified products with an AAAA rating are released directly, and unqualified products with two or more B ratings are stored uniformly and processed at the right time. This classification method improves the efficiency of production management and rationally plans the flow of products of different quality.

[0111] The text quality index WZ, color quality index SC, area quality index MJ and ink contamination index YM of the product to be analyzed are normalized and then entered into the formula: Get the printing quality index YSZ, where λ1 、 λ2 、 λ3 and λ4 are the weighted influencing factors corresponding to the text quality index WZ, the color quality index SC, the area quality index MJ and the ink contamination index YM respectively;

[0112] A printing quality index threshold is preset according to the quality requirements of the currently produced cigarette packaging paper printed product. If the quality index YSZ of the cigarette packaging paper printed product is lower than the preset printing quality index threshold, it is determined that the quality of the current cigarette packaging paper printed product is unqualified; otherwise, the quality of the cigarette packaging paper printed product is qualified;

[0113] For unqualified cigarette packaging paper printed products, the preset printing quality index threshold is used to subtract the printing quality index YSZ to obtain the index difference, and the preset index difference threshold is set. If the index difference is less than the preset index difference threshold, the current cigarette packaging paper printed products are stored in the warehouse and will be shipped out when the next production quality requirement decreases; if the index difference is greater than the preset index difference threshold, the current cigarette packaging paper printed products are directly scrapped;

[0114] For products that do not meet the quality standards, the products are either stored in a warehouse for waiting or directly scrapped, depending on the comparison between the index difference and the preset index difference threshold. This refined processing method helps reduce production costs, avoid unnecessary waste of resources, and ensure that product quality meets production requirements.

[0115] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A visual inspection system for the surface quality of printed cigarette packaging paper, characterized in that: include: Image acquisition module: Set up LED array light source according to the material, color and surrounding environment of the detected cigarette packaging paper print, build a light source environment, use industrial camera to obtain the surface image of cigarette packaging paper print, and send the surface image of cigarette packaging paper print to text quality analysis module, color quality analysis module, area quality analysis module and ink pollution analysis module; Color quality analysis module: used to divide the cigarette packaging paper printed products into regions and analyze the color quality of each divided region to obtain the color quality index SC; and to process the current cigarette packaging paper printed products accordingly and determine the color rating according to the specific value of the color quality index SC; Area quality analysis module: used to analyze the area and position of each area of ​​the cigarette packaging paper print, so as to obtain the area quality index MJ; and to process the current cigarette packaging paper print accordingly and determine the area rating according to the specific value of the area quality index MJ; Ink pollution analysis module: used to analyze the ink pollution of cigarette packaging paper printing products, so as to obtain the ink pollution index YM; And according to the specific value of the ink pollution index YM, the current cigarette packaging paper printing products are processed accordingly and the ink rating is determined; Text quality analysis module: used to analyze the text quality of cigarette packaging paper prints, thereby obtaining a text quality index WZ; and to process the current cigarette packaging paper prints accordingly and determine the text rating according to the specific value of the text quality index WZ; Printing quality analysis module: used to analyze the four indexes and ratings received and process the cigarette packaging paper prints accordingly.

2. A surface quality visual inspection system for cigarette packaging paper printed products according to claim 1, characterized in that: The specific processing steps of the color quality analysis module are: A1: Preprocess the surface image of the cigarette packaging paper print obtained, divide the surface image of the cigarette packaging paper print into various regions; establish a four-color channel histogram of the corresponding region on each divided region, where the four colors refer to cyan, magenta, yellow and black; and perform the same region division and histogram establishment on the standard style image of the cigarette packaging paper print; A2: For the histogram of each channel in each region of the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper, only the number of pixels or the frequency corresponding to the color intensity value is retained, so as to obtain the line graph of each channel in each region of the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper, and align the line graphs corresponding to the surface image of the printed cigarette wrapper and the standard style image of the printed cigarette wrapper in the same region and the same channel to the same coordinate system; A3: Count the number of overlapping points of the two line graphs, subtract the number of overlapping points from 255, and get the number of heterochromaticity Q1. At the same time, connect the two starting points and the two end points of the two line graphs to obtain the area enclosed by the two line graphs, which is recorded as the heterochromaticity area Q2. After normalizing the number of heterochromaticity Q1 and the heterochromaticity area Q2, they are inserted into the formula: QY = Q1*d1+Q2*d2 to obtain the color difference index QY, where d1 and d2 are the weight influence factors corresponding to the number of heterochromaticity Q1 and the heterochromaticity area Q2 respectively. A4: The four-color channel histograms corresponding to the surface image of the cigarette packaging paper print and the standard style image of the cigarette packaging paper print in each area are processed in step A3 above, so as to obtain the color difference index corresponding to each channel of each area, and the average value of the four-color channel color difference index QY of each area is taken to obtain the color evaluation index of each area; each weight influence factor corresponding to each area is preset, and the color evaluation index of each area is multiplied by the corresponding weight factor to obtain the color quality index SC of the surface image of the cigarette packaging paper print; A5: Determine the color quality index threshold according to the quality requirements of the current batch of cigarette packaging paper prints. If the color quality index SC is higher than the preset color quality index threshold, the color quality of the current cigarette packaging paper prints is judged to be unqualified; otherwise, the color quality is qualified and the color rating is recorded as A; A6: For cigarette packaging paper printed products with unqualified colors, the color quality index threshold is subtracted from the color quality index SC to obtain a color quality difference. The color quality difference threshold is preset. If the color quality difference is greater than the preset color quality difference threshold, the current cigarette packaging paper printed products are scrapped. Otherwise, the color rating is recorded as B; A7: Send the color quality index SC and color rating to the printing analysis module.

3. The surface quality visual inspection system for cigarette packaging paper printed products according to claim 1, characterized in that: The specific processing steps of the area quality analysis module are: D1: Using the surface image of the cigarette packaging paper print obtained in step A1 and each area of ​​the standard style image of the cigarette packaging paper print, number each area and use QY i The numbering of each area of ​​the surface image of the cigarette packaging paper print is used The numbering of each area of ​​the standard style image of the cigarette packaging paper print, i = 1, 2...n, n represents the total number of areas after division; the lower left corner of the cigarette packaging paper print is recorded as the marking point, a rectangular coordinate system is established, the area numbered QY1 is selected, a point on the edge of the area is randomly selected, recorded as the target point, the target point is connected with the marking point to form a line segment, the length of the line segment is obtained, recorded as the target distance, the angle between the line segment and the horizontal edge of the print is obtained, recorded as the target angle, the selected surface image area of ​​the cigarette packaging paper print is placed in the rectangular coordinate system, the target point is connected to the coordinate origin, and the selected surface image area of ​​the cigarette packaging paper print is fixed to the coordinate system according to the target distance and the target angle; at the same time, the numbered The same operation is performed on the area corresponding to QY1 and The corresponding areas correspond to the same rectangular coordinate system; D2: Get the area and value corresponding to QY1 in the rectangular coordinate system The overlapping area of ​​the corresponding regions is recorded as the correct area, and the The area of ​​the corresponding region is Subtract the correct area from the area of ​​the corresponding region to obtain the error area, and divide the error area by The area of ​​the corresponding region is used to obtain the position error rate; D3: Get the area of ​​the region corresponding to QY1, using the formula: Thus, the area error rate MJ is obtained, where It is the allowable area error of the area numbered QY1; D4: preset the weighted influence factors corresponding to the position error rate and the area error rate MJ, multiply the position error rate and the area error rate MJ by the corresponding weighted influence factors and then sum them up to obtain the comprehensive area error index of the area numbered QY1; D5: performing the above-mentioned operations D1-D4 on each area of ​​the divided surface image of the cigarette packaging paper print, thereby obtaining a comprehensive area error index of each area on the surface image of the cigarette packaging paper print, presetting a weight influence factor of each area on the surface image of the cigarette packaging paper print, and multiplying the comprehensive area error index of each area on the surface image of the cigarette packaging paper print by the corresponding weight influence factor, thereby obtaining an area quality index MJ of the surface image of the cigarette packaging paper print; D6: Determine the area quality index threshold according to the quality requirements of the current batch of cigarette packaging paper printed products. If the area quality index MJ is higher than the preset area quality index threshold, the area quality of the current cigarette packaging paper printed products is judged to be unqualified. Otherwise, the area quality is qualified and the area rating is recorded as A. D7: For cigarette packaging paper printed products with unqualified area quality, the area quality index MJ is subtracted from the area quality index threshold to obtain the area quality difference. The area quality difference threshold is preset. If the area quality difference is greater than the preset area quality difference threshold, the current cigarette packaging paper printed product is scrapped; Otherwise, the area rating is recorded as B; D8: Send the area quality index and area rating to the printing analysis module.

4. The surface quality visual inspection system for cigarette packaging paper printed products according to claim 1, characterized in that: The specific processing steps of the ink contamination analysis module are: R1: Use color analysis and edge detection algorithms to mark the ink area pollution on the surface image of the cigarette packaging paper print, associate the pollution area marked by color analysis with the pollution boundary obtained by edge detection, so as to obtain the ink pollution area on the surface image of the cigarette packaging paper print, and obtain the area of ​​each ink pollution area and the surface image area of ​​the cigarette packaging paper print where it is located; R2: If an ink contaminated area passes through multiple cigarette packaging paper printed product surface image areas, then the area of ​​the ink area on each cigarette packaging paper printed product surface image area is obtained, recorded as the zone area, and the zone area is divided by the area of ​​the ink contaminated area to obtain the contamination ratio of the ink contaminated area on each cigarette packaging paper printed product surface image area, and the contamination ratio is multiplied by the weight influence factor of the corresponding cigarette packaging paper printed product surface image area to obtain the weight influence factor of the ink area; if the ink contaminated area only passes through one cigarette packaging paper printed product surface image area, the weight influence factor of the corresponding cigarette packaging paper printed product surface image area is used as the weight influence factor of the ink area; R3: Obtain the area of ​​each ink contaminated area and the corresponding weight influence factor, and multiply the area of ​​the ink contaminated area by the corresponding weight influence factor to obtain the ink contamination index YM; R4: Determine the ink contamination index threshold value according to the quality requirements of the current batch of cigarette packaging paper printed products. If the ink contamination index MJ is higher than the preset ink contamination index threshold value, the ink quality of the current cigarette packaging paper printed products is judged to be unqualified. Otherwise, the ink quality is qualified and the ink rating is recorded as A. R5: For cigarette packaging paper printed products with unqualified ink quality, the ink pollution index YM is subtracted from the ink pollution index threshold to obtain the ink quality difference, and the ink quality difference threshold is preset. If the ink quality difference is greater than the preset ink quality difference threshold, the current cigarette packaging paper printed product is scrapped; Otherwise, the ink rating is recorded as B; R6: Send the ink contamination index YM and ink rating to the printing analysis module.

5. The surface quality visual inspection system for cigarette packaging paper printed products according to claim 1, characterized in that: The specific processing steps of the text quality analysis module are: W1: Use image analysis software to locate the text part of the surface image of the cigarette packaging paper print. For each word, obtain the top and bottom parts of the image and draw two horizontal lines; obtain the left and right parts of the image and draw two vertical lines. The four lines will enclose a rectangular closed area. The area of ​​the rectangular closed area is used as the occupied area F1 of the corresponding word. Obtain the standard occupied area F2 of the corresponding word from the standard style image of the cigarette packaging paper print, using the formula: Obtain the size score WZF of the corresponding text; take the average of all the text size scores as the comprehensive score CC of the text size of the cigarette packaging paper print; W2: Use image analysis software to generate edge strength images for text, obtain pixel values ​​of all points on the text edge, as the edge strength of the corresponding points, use mean formula and standard deviation formula to calculate the edge strength of all points of the text, and use the obtained values ​​as the text mean and text wave value respectively. Divide the text wave value by the text mean to obtain the fuzzy index of the text; take the mean of all text fuzzy indexes as the comprehensive fuzzy index MH of the text printed on cigarette packaging paper; W3: Use image analysis software to locate each text area on the surface image of the cigarette packaging paper print product, and obtain the comprehensive text spacing index JG of the cigarette packaging paper print product; W4: After normalizing the text size comprehensive score CC, text fuzzy comprehensive index MH and comprehensive text spacing index JG of the printed matter on cigarette packaging paper, they are inserted into the formula: The text quality index WZ is obtained, where v1, v2 and v3 are weighted influencing factors corresponding to the comprehensive score CC of the text size, the comprehensive text spacing index JG and the comprehensive text fuzziness index MH of the printed matter of cigarette packaging paper respectively; W5: Determine the text quality index threshold according to the quality requirements of the current batch of cigarette packaging paper prints. If the text quality index WZ is lower than the preset text quality index threshold, the text quality of the current cigarette packaging paper prints is judged to be unqualified; otherwise, the text quality is qualified and the text rating is recorded as A; W6: For cigarette packaging paper printed products with unqualified text quality, the text quality index WZ is subtracted from the text quality index threshold to obtain the text quality difference. The text quality difference threshold is preset. If the text quality difference is greater than the preset ink text quality difference threshold, the current cigarette packaging paper printed product is scrapped; Otherwise, the text rating is B; W7: Send the text quality index WZ and text rating to the printing analysis module.

6. A surface quality visual inspection system for cigarette packaging paper printed products according to claim 5, characterized in that: The specific steps of obtaining the comprehensive character spacing index JG of cigarette packaging paper are as follows: W3-1: For two adjacent characters, obtain the rightmost point of the left character and the leftmost point of the right character, calculate the horizontal distance between the two points, and use it as the distance between the two adjacent characters; Get the distances between all adjacent characters in the area, thereby obtaining a character distance set; The standard text distance of the area is obtained from the standard style image of the cigarette packaging paper print, and an allowable error is preset according to the quality requirements of the current batch of cigarette packaging paper prints, and the manufacturing interval is calculated. The standard text distance of the area plus the allowable error is used as the maximum value of the manufacturing interval, and the standard text distance of the area minus the allowable error is used as the minimum value of the manufacturing interval; Extract the data that are not in the manufacturing interval from the text distance set, and form a new set of the obtained data as the error set; W3-2: For data in the error set, if it is greater than the maximum value of the manufacturing interval, the maximum value of the manufacturing interval is subtracted from the data, and the result is taken as the error difference of the data; If it is less than the minimum value of the manufacturing interval, subtract the data from the minimum value of the manufacturing interval, and the result is taken as the error difference of the data; Preset the error difference interval, set each error difference interval to correspond to each error score, match the error difference interval corresponding to the error difference of the data in the error set, so as to obtain the error score of each data in the error set; take the average of all error scores as the distance error score of the area; W3-3: Perform operations from W3-1 to W3-2 on each text area to obtain the distance error score corresponding to each text area, and take the average of the distance error scores of each area as the comprehensive text spacing index JG of the cigarette packaging paper print.

7. The surface quality visual inspection system for cigarette packaging paper printed products according to claim 1, characterized in that: The specific processing steps of the quality analysis module are: The four ratings are arranged in the order of color, area, ink and text to obtain a comprehensive rating. If the comprehensive rating is AAAA, the quality of the current cigarette packaging paper printing product is considered qualified; If there are two or more Bs in the comprehensive rating, the quality of the current cigarette packaging paper print is judged to be unqualified, and the current cigarette packaging paper print is stored in the warehouse and waits for the next production quality requirement to be reduced before being released from the warehouse; if the number of Bs in the comprehensive rating is less than or equal to 2, the current cigarette packaging paper print is judged to be a product to be analyzed, and the four indexes of the product to be analyzed are analyzed as follows: The text quality index WZ, color quality index SC, area quality index MJ and ink contamination index YM of the product to be analyzed are normalized and then entered into the formula: Get the printing quality index YSZ, where λ1 、 λ2 、 λ3 and λ4 are the weighted influencing factors corresponding to the text quality index WZ, the color quality index SC, the area quality index MJ and the ink contamination index YM respectively; A printing quality index threshold is preset according to the quality requirements of the currently produced cigarette packaging paper printed product. If the quality index YSZ of the cigarette packaging paper printed product is lower than the preset printing quality index threshold, it is determined that the quality of the current cigarette packaging paper printed product is unqualified; otherwise, the quality of the cigarette packaging paper printed product is qualified; For unqualified cigarette packaging paper printed materials, the preset printing quality index threshold is subtracted from the printing quality index YSZ to obtain the index difference. If the index difference is less than the preset index difference threshold, the current cigarette packaging paper printed materials are stored in the warehouse and will not be shipped out until the next production quality requirement is reduced; if the index difference is greater than the preset index difference threshold, the current cigarette packaging paper printed materials are directly scrapped.

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