CN115311277A - Pit defect identification method for stainless steel product - Google Patents

Pit defect identification method for stainless steel product Download PDF

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CN115311277A
CN115311277A CN202211242194.7A CN202211242194A CN115311277A CN 115311277 A CN115311277 A CN 115311277A CN 202211242194 A CN202211242194 A CN 202211242194A CN 115311277 A CN115311277 A CN 115311277A
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pixel
stainless steel
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CN115311277B (en
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严惠卫
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Nantong Melco Material Technology Co ltd
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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/0002Inspection of images, e.g. flaw detection
    • G06T7/0004Industrial image inspection
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/10Segmentation; Edge detection
    • G06T7/11Region-based segmentation
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/10Segmentation; Edge detection
    • G06T7/187Segmentation; Edge detection involving region growing; involving region merging; involving connected component labelling
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00Arrangements for image or video recognition or understanding
    • G06V10/20Image preprocessing
    • G06V10/26Segmentation of patterns in the image field; Cutting or merging of image elements to establish the pattern region, e.g. clustering-based techniques; Detection of occlusion
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00Arrangements for image or video recognition or understanding
    • G06V10/70Arrangements for image or video recognition or understanding using pattern recognition or machine learning
    • G06V10/762Arrangements for image or video recognition or understanding using pattern recognition or machine learning using clustering, e.g. of similar faces in social networks
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P90/00Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
    • Y02P90/30Computing systems specially adapted for manufacturing

Abstract

The invention relates to the technical field of image data identification, in particular to a pit defect identification method of a stainless steel product, which comprises the following steps: acquiring RGB images of the surface of the stainless steel metal through identification, converting the RGB images into LAB images, segmenting the images, and identifying connected domains to obtain a plurality of connected domains; calculating the density of the pixel points, and determining a clustering center according to the density; calculating the distance between the clustering centers to further obtain an optimal clustering center; and determining the optimal clustering center according to the distance from the optimal clustering center to other pixel points, and further performing superpixel segmentation to obtain a defect region image to obtain a pit defect region of the stainless steel product. The invention can obtain an accurate super-pixel segmentation result, so that an accurate pit area can be identified and obtained.

Description

Pit defect identification method for stainless steel product
Technical Field
The invention relates to the technical field of image data identification, in particular to a pit defect identification method for a stainless steel product.
Background
In the process of warehousing and transportation of stainless steel products, the screw bolts on the transportation frame are loosened, and the screw caps are raised, so that the pits can be damaged by the cushion.
In the patent CN202111587840.9, when the surface pit defect of the product is detected, the gray level image is subjected to sliding window to obtain the gray level co-occurrence matrix of each sliding window area, and the contrast value of each sliding window area is clustered to obtain possible pit pixels; calculating the directional heart rate; acquiring coordinates of all pixel points which are greater than a first threshold value; making a circle by using the coordinate mean value of the pixel points of the same pit, and calculating the gradient coincidence rate; and changing the set radius, obtaining all the maximum gradient coincidence rates, performing Gaussian smoothing to obtain boundary circles of corresponding angles, and fitting to obtain pit boundaries. The method has the defects that the contrast value of the gray level co-occurrence matrix of the sliding window area obtained by identification is calculated, and then clustering is carried out according to the contrast to obtain possible pit pixels. Clustering is carried out according to the contrast value, and due to the fact that the metal product is greatly influenced by illumination and the like, the contrast of a sunken area and a non-sunken area is also large, and therefore the problem that partial pit pixel points cannot be accurately divided exists.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a method for identifying the pit defects of a stainless steel product, which adopts the following technical scheme:
acquiring RGB images of the surface of the stainless steel metal through identification, converting the RGB images into LAB images, segmenting the images, and identifying connected domains to obtain a plurality of connected domains;
calculating the density of the pixel points with the same pixel value according to the pixel values of the pixel points of all connected domains, and taking the pixel point with the maximum density as a clustering center; the clustering center is a 3 multiplied by 3 pixel block, and pixel values of pixel points in the pixel block are equal;
determining three clustering centers belonging to the same region according to the distances among the three clustering centers, calculating the pixel value mean values of the three clustering centers, and taking the pixel value mean value meeting a threshold value as an optimal clustering center;
and calculating the distance between other pixel points and each pixel point in the optimal clustering center according to the pixel value of each channel of the pixel point in the LAB color space, acquiring the pixel point in the optimal clustering center corresponding to the minimum value of the distance of any pixel point as the optimal clustering center of the pixel point, and further performing superpixel segmentation to obtain a defect region image and obtain a pit defect region of the stainless steel product.
Preferably, the segmenting the image is specifically: and segmenting the image by using an OTSU threshold segmentation algorithm.
Preferably, the method for obtaining the density of the pixel points of the same pixel value specifically comprises:
Figure 279841DEST_PATH_IMAGE002
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE003
indicating the density of pixel points having the same pixel value,
Figure 392285DEST_PATH_IMAGE004
representing a pixel value of
Figure DEST_PATH_IMAGE005
The number of the pixel points of (a) is,
Figure 166206DEST_PATH_IMAGE006
represents the number of levels of the pixel value,
Figure DEST_PATH_IMAGE007
representing a pixel value of
Figure 641180DEST_PATH_IMAGE005
The ratio of the pixel points in the area,
Figure 248879DEST_PATH_IMAGE008
indicating the distance between pixels having the same pixel value.
Preferably, the preferable clustering center that the pixel value mean satisfies the threshold is specifically:
the condition that the distance satisfies the threshold is:
Figure 425783DEST_PATH_IMAGE010
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE011
Figure 485618DEST_PATH_IMAGE012
Figure 939733DEST_PATH_IMAGE012
the distance between the centers of the three clusters is indicated,
Figure DEST_PATH_IMAGE013
Figure 311809DEST_PATH_IMAGE014
respectively representing the coordinates of the central pixel points of the two cluster centers.
Preferably, the calculating the distance between the other pixel points and each pixel point in the cluster center according to the pixel value of each channel of the pixel point in the LAB color space specifically includes:
Figure 726741DEST_PATH_IMAGE016
Figure 248989DEST_PATH_IMAGE018
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE019
which represents the distance of the color between the pixels,
Figure 151086DEST_PATH_IMAGE020
which represents the spatial distance between the pixels,
Figure DEST_PATH_IMAGE021
Figure 179216DEST_PATH_IMAGE022
Figure DEST_PATH_IMAGE023
Figure 533974DEST_PATH_IMAGE024
Figure DEST_PATH_IMAGE025
Figure 858DEST_PATH_IMAGE026
coordinates of pixel values of respective channels in the LAB color space are respectively expressed.
Figure DEST_PATH_IMAGE027
Figure 757462DEST_PATH_IMAGE028
Are spatial coordinates.
The embodiment of the invention at least has the following beneficial effects:
the invention selects the clustering center according to the characteristics of the image, carries out superpixel segmentation on the image, and identifies and obtains the superpixel block, thereby achieving the purpose of defect detection. And the optimal clustering center is obtained through three times of iterative identification, and can reflect the pixel relationship among the edge of the pit, the inner wall of the pit and the central bright spot, so that the accurate pit area can be identified and obtained by performing superpixel segmentation according to the optimal clustering center.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions and advantages of the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a flow chart of a method of identifying a pit defect in a stainless steel article according to the present invention.
Detailed Description
To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description will be given to a method for identifying a pit defect of a stainless steel product according to the present invention, and the detailed description, structure, features and effects thereof with reference to the accompanying drawings and preferred embodiments. In the following description, the different references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
The following describes a specific scheme of the method for identifying the pit defects of the stainless steel product provided by the invention in detail by combining with the accompanying drawings.
The embodiment is as follows:
the specific scenes aimed by the invention are as follows: when the pit defect on the surface of the stainless steel product is detected, because the metal surface can reflect light, when the pit is extracted, the edge extracted is inaccurate due to edge blurring.
Referring to fig. 1, a flowchart of a method for identifying a pit defect of a stainless steel product according to an embodiment of the present invention is shown, where the method includes the following steps:
the method comprises the steps of firstly, acquiring RGB images of the surface of the stainless steel metal through recognition, converting the RGB images into LAB images, segmenting the images, and recognizing connected domains to obtain a plurality of connected domains.
Specifically, the pit defect on the surface of the stainless steel product needs to be detected, so that a surface image of the stainless steel metal needs to be acquired. Because the color characteristics of the LAB color space are more obvious, the LAB color space is more suitable for the application scene of the invention. Converting the RGB image to the LAB color space is a well known technique and will not be described in detail here.
Because the edge of the pit can form a bright edge line, the protruding degree of the edge is higher than that of the flat area, the central position of the pit can also form a bright area, and the pixel value of the bright area is larger than that of the inner wall of the pit, when the initial edge pixel point of the image is obtained through identification, the initial edge pixel point of the image needs to be segmented according to the change of the pixel value of the image edge pixel point, and the edge pixel point of the suspected pit area is searched.
Since the edge of the pit forms a certain protrusion, a shadow-like region is formed on the inner side or the outer side of the edge, but the edge is blurred due to reflection, and the blurred region and the normal edge region cannot be accurately connected together, in this embodiment, the image is firstly segmented by an OTSU threshold segmentation algorithm, and the segmented image is identified to obtain an initial connected domain. However, a plurality of connected domains can be formed by a pit defect, the bright edge of the outermost circle, the inner wall of the pit with a smaller pixel value and the center position of the pit need to select the optimal clustering center during clustering, and then the image is subjected to superpixel segmentation.
The selection of the clustering center of the invention relates to the accuracy of superpixel segmentation, so that the clustering center is determined according to the pixel densities of different connected domains when the clustering center is searched. Because the pixel value change of each connected domain is different in the three connected domains of a pit area, the pixel value of the pixel point in the central area of the pit is larger and is densely distributed, and a bright circular spot is formed; the inner wall pixel value of the pit is smaller and is positioned in a transition area of two areas, namely the edge of the pit and the center of the pit; while the peripheral edge region forms a larger area with the flat region due to the reflection.
It should be noted that, the present invention needs to detect the surface pit defect of the stainless steel product, because the surface of the stainless steel product reflects light, when the surface of the stainless steel product is subjected to threshold segmentation, the segmented pit edge is inaccurate due to unclear boundary. Therefore, in order to obtain an accurate pit edge, the embodiment first identifies an edge initial pixel point of a suspected pit defect in an obtained image as a clustering center, then performs superpixel segmentation on the image, and identifies a superpixel block of the obtained image.
Calculating the density of pixel points with the same pixel value according to the pixel values of the pixel points in each region, and taking the pixel point with the maximum density as a clustering center; the clustering center is a 3 x 3 pixel block, and the pixel values of the pixel points in the pixel block are equal.
Specifically, the density of the pixels with the same pixel value in each region is calculated, and the most clustered center pixel of the pixel with the highest density is calculated, and the pixels with the same pixel value must be continuous pixels.
Assume that the pixel value of a pixel point of a certain connection domain is
Figure DEST_PATH_IMAGE029
And calculating the density of the pixel points with the same pixel value by the following calculation formula:
Figure 230861DEST_PATH_IMAGE030
in the formula (I), the compound is shown in the specification,
Figure 745019DEST_PATH_IMAGE003
indicating the density of pixel points having the same pixel value,
Figure 733704DEST_PATH_IMAGE004
representing a pixel value of
Figure 751338DEST_PATH_IMAGE005
The number of the pixel points of (a),
Figure 183588DEST_PATH_IMAGE006
represents the number of levels of the pixel value,
Figure 919463DEST_PATH_IMAGE007
representing a pixel value of
Figure 711838DEST_PATH_IMAGE005
The number of the pixel points in the area is proportional,
Figure 583979DEST_PATH_IMAGE008
representing the distance between pixels having the same pixel value, wherein
Figure DEST_PATH_IMAGE031
Representing a pixel value of
Figure 655972DEST_PATH_IMAGE005
The distance between the pixels of (a) and (b),
Figure 3776DEST_PATH_IMAGE032
representing pixels
Figure 209630DEST_PATH_IMAGE029
The horizontal and vertical coordinates of (a) and (b),
Figure DEST_PATH_IMAGE033
representing all possibilities for combination between two regions, 2 represents the repeated calculation between two regions, so a division by 2 is required. Through calculating the distance between two liang of pixel points, then ask the mean value to all distances, express regional density, the quantity that has the pixel of the same pixel value in same connected domain is more, and the density of the more close pixel of distance between the pixel is big more. Namely that
Figure 546064DEST_PATH_IMAGE003
Is a pixel value of
Figure 303805DEST_PATH_IMAGE005
The density of the pixel points.
The density of the pixel points with the same pixel value in the same connected domain is calculated, and the pixel point with the maximum density is used as a clustering center, but the pixel point of the clustering center is required to be a continuous pixel point, so that a 3 x 3 template is required to be screened and selected. Namely, the pixel point with the maximum density is obtained as the central pixel point of the pixel block of 3 × 3, the pixel values of the surrounding neighborhood pixel points of the pixel point are the same as the pixel value of the central pixel point, then the pixel block is used as the clustering center, and the mathematical expression is as follows:
Figure 748693DEST_PATH_IMAGE034
. The clustering centers of different areas are identified and obtained by the same method, and the clustering centers are not single pixel points but one
Figure DEST_PATH_IMAGE035
The advantage of selecting the cluster center is as follows: one point is not randomly selected, but a point with the maximum density is selected from all data points to serve as a first initial clustering center point, the possibility of selecting outliers is avoided to a certain extent, and meanwhile, the value of a proper radius needs to be adjusted.
And step three, determining three clustering centers belonging to the same region according to the distances among the three clustering centers, calculating the pixel value mean values of the three clustering centers, and taking the pixel value mean values meeting a threshold value as an optimal clustering center.
In particular, according to the cluster center obtained by the above identification, since the final purpose is to divide the same pit defect rather than different connected domains when performing superpixel division, the pixel relationship between the stainless steel metal pit connected domains needs to be considered. And then performing super-pixel segmentation according to edge variation between different connected domains.
In the threshold segmentation process, three connected domains of the same pit, namely the bright edge at the outermost circle, the pit inner wall with a smaller pixel value and the pit center position are identified and obtained, and the final clustering center is determined according to the clustering centers of the three connected domains obtained by identification. The change of the edge pixel values of the three connected domains is severe, so that the pixel points at the edge cannot be selected when the clustering center is selected, and excessive segmentation is prevented when segmentation is performed.
Because the cluster center selected for the first time is one
Figure 365094DEST_PATH_IMAGE035
Selecting three proper pixel blocks, and calculating the pixel mean value of the pixel blocks to be used as the clustering center of the same area. Is provided withOne is
Figure 602040DEST_PATH_IMAGE036
The sliding window is formed by sliding the pixel block with the maximum pixel value in four directions of up, down, left and right to calculate the pixel average value in the sliding window
Figure DEST_PATH_IMAGE037
Because the biggest pixel of pixel value is marginal pixel or central pixel, so in the in-process that slides to four directions, the sliding window that has at least one direction can pass through three connected domain, and the average pixel value of sliding window can big to the size grow again, consequently calculates the distance D of three clustering piece according to the change of sliding window pixel value, if the distance satisfies:
Figure 750256DEST_PATH_IMAGE010
in the formula (I), the compound is shown in the specification,
Figure 948019DEST_PATH_IMAGE011
Figure 354730DEST_PATH_IMAGE012
Figure 321549DEST_PATH_IMAGE012
and representing the distance between the three clustering centers, wherein the distance can be obtained by calculating the pixel distance between the center pixel points of the clustering centers or the Euclidean distance between the center pixel points.
Figure 171824DEST_PATH_IMAGE038
Representing the distance between two sliding windows in different connected domains where the pixel value is largest.
Figure 856884DEST_PATH_IMAGE013
Figure 332864DEST_PATH_IMAGE014
Respectively representing the coordinates of the central pixel points of the two clustering centers.And determining three clustering pixel blocks belonging to the same region in the three connected domains obtained by segmentation according to the change of the pixel values of the pixel points.
Then, calculating the pixel mean value of the three cluster pixel blocks according to the obtained three cluster pixel blocks
Figure DEST_PATH_IMAGE039
Then the pixel block that satisfies the pixel value is taken as the new cluster center. Because there are a plurality of pixel points satisfying the threshold, but the selected clustering center only needs one pixel block, the calculation is satisfied at
Figure 498398DEST_PATH_IMAGE035
And taking the pixel blocks with the same pixel value in the template as a new cluster center, and marking as a preferred cluster center.
And step four, calculating the distance between other pixel points and each pixel point in the clustering center according to the pixel value of each channel of the pixel point in the LAB color space, obtaining the pixel point in the clustering center corresponding to the minimum value of the distance of any pixel point as the optimal clustering center of the pixel point, and further carrying out superpixel segmentation to obtain a defect region image and obtain a pit defect region of the stainless steel product.
Specifically, a new cluster center of the pit region is identified and obtained by the above method, and superpixel segmentation is performed according to the identified and obtained optimal cluster center. Firstly, the distance between pixels is calculated, wherein the distance between each pixel point in the area and the clustering center is calculated by using a mode of combining the color distance and the space distance, and the calculation formula is as follows:
Figure 909787DEST_PATH_IMAGE016
Figure 941197DEST_PATH_IMAGE018
in the formula (I), the compound is shown in the specification,
Figure 830656DEST_PATH_IMAGE019
which represents the distance of the color between the pixels,
Figure 568805DEST_PATH_IMAGE020
representing the spatial distance between the pixels,
Figure 757953DEST_PATH_IMAGE021
Figure 152025DEST_PATH_IMAGE022
Figure 969809DEST_PATH_IMAGE023
Figure 765726DEST_PATH_IMAGE024
Figure 128706DEST_PATH_IMAGE025
Figure 10074DEST_PATH_IMAGE026
coordinates of pixel values of respective channels in the LAB color space are respectively expressed.
Figure 365969DEST_PATH_IMAGE027
Figure 16393DEST_PATH_IMAGE028
Are spatial coordinates. The formula is the existing formula and is not logically explained. The final metric distance is then calculated
Figure 815853DEST_PATH_IMAGE040
Because each pixel point can be searched by a plurality of seed points, each pixel point has a distance with the surrounding seed points, and the seed point corresponding to the minimum value is taken as the optimal clustering center of the pixel point. I.e. due to the cluster center being one
Figure 184517DEST_PATH_IMAGE035
The pixel blocks of (1) so that other pixel points are all in the cluster centerThe distance of each pixel point is needed to obtain the pixel point in the clustering center corresponding to the minimum distance value as the optimal clustering center of other pixel points.
Further, superpixel segmentation is carried out according to the obtained optimal clustering center, because threshold segmentation processing is carried out on the image in the steps, a defect area is obtained through identification, only part of the edge of the defect area is not clear, a clear and accurate edge is obtained after superpixel segmentation identification, the image obtained after the original image is subjected to threshold segmentation is superposed with the image obtained after the superpixel segmentation, a defect area image is obtained, further, a pit defect area of a stainless steel product can be identified and obtained, and the defect area is marked, so that manual check is facilitated.
Finally, it is to be noted that connected domains are obtained through threshold segmentation and identification, then density clustering is carried out on the connected domains according to the characteristics of the images, and an initial clustering center is obtained through identification, wherein the clustering center is the clustering center of a certain connected domain; and identifying and obtaining iterative clustering centers according to the change of the edge pixels, identifying and obtaining the clustering centers of the iterative clustering centers which represent the defect areas of the whole pit, finally identifying and obtaining the optimal clustering centers according to the distance between the pixels, carrying out super-pixel segmentation on the image, and identifying and obtaining accurate defect areas.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; the modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application, and are included in the protection scope of the present application.

Claims (5)

1. A method for identifying a pit defect in a stainless steel product, the method comprising:
acquiring RGB images of the surface of the stainless steel metal through identification, converting the RGB images into LAB images, segmenting the images, and identifying connected domains to obtain a plurality of connected domains;
calculating the density of the pixel points with the same pixel value according to the pixel values of the pixel points of each connected domain, and taking the pixel point with the highest density as a clustering center; the clustering center is a 3 multiplied by 3 pixel block, and pixel values of pixel points in the pixel block are equal;
determining three clustering centers belonging to the same region according to the distances among the three clustering centers, calculating the pixel value mean values of the three clustering centers, and taking the pixel value mean value meeting a threshold value as an optimal clustering center;
and calculating the distance between other pixel points and each pixel point in the optimal clustering center according to the pixel value of each channel of the pixel point in the LAB color space, acquiring the pixel point in the optimal clustering center corresponding to the minimum value of the distance of any pixel point as the optimal clustering center of the pixel point, and further performing superpixel segmentation to obtain a defect region image and obtain a pit defect region of the stainless steel product.
2. The method for identifying the pit defect of the stainless steel product according to claim 1, wherein the segmenting the image is specifically as follows: and segmenting the image by using an OTSU threshold segmentation algorithm.
3. The method for identifying the pit defect of the stainless steel product according to claim 1, wherein the method for obtaining the density of the pixel points with the same pixel value specifically comprises the following steps:
Figure DEST_PATH_IMAGE001
in the formula (I), the compound is shown in the specification,
Figure 523058DEST_PATH_IMAGE002
indicating the density of pixel points having the same pixel value,
Figure 27989DEST_PATH_IMAGE003
representing a pixel value of
Figure 263929DEST_PATH_IMAGE004
The number of the pixel points of (a),
Figure 119890DEST_PATH_IMAGE005
represents the number of levels of the pixel value,
Figure 817588DEST_PATH_IMAGE006
representing a pixel value of
Figure 442604DEST_PATH_IMAGE004
The percentage of the pixel points in the area,
Figure 583866DEST_PATH_IMAGE007
the distance between the pixels with the same pixel value is represented.
4. A method for identifying a pit defect in a stainless steel product according to claim 1, wherein the preferred clustering center that is the pixel value mean satisfying the threshold is specifically:
the condition that the distance satisfies the threshold is:
Figure 661544DEST_PATH_IMAGE008
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE009
Figure 975982DEST_PATH_IMAGE010
Figure 455505DEST_PATH_IMAGE010
the distance between the centers of the three clusters is indicated,
Figure 16936DEST_PATH_IMAGE011
Figure 581909DEST_PATH_IMAGE012
respectively representing the coordinates of the central pixel points of the two cluster centers.
5. The method for identifying the pit defect of the stainless steel product according to claim 1, wherein the step of calculating the distance between other pixel points and each pixel point in the cluster center according to the pixel value of each channel of the pixel point in the LAB color space specifically comprises the following steps:
Figure 369212DEST_PATH_IMAGE013
Figure 968821DEST_PATH_IMAGE014
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE015
which represents the distance in color between the pixels,
Figure 169995DEST_PATH_IMAGE016
representing the spatial distance between the pixels,
Figure DEST_PATH_IMAGE017
Figure 566473DEST_PATH_IMAGE018
Figure 409664DEST_PATH_IMAGE019
Figure 863779DEST_PATH_IMAGE020
Figure 783324DEST_PATH_IMAGE021
Figure 57311DEST_PATH_IMAGE022
coordinates representing pixel values of respective channels in the LAB color space,
Figure 969772DEST_PATH_IMAGE023
Figure 278394DEST_PATH_IMAGE024
are spatial coordinates.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112489025A (en) * 2020-12-07 2021-03-12 南京钢铁股份有限公司 Method for identifying pit defects on surface of continuous casting billet
CN114998198A (en) * 2022-04-24 2022-09-02 南通夏克塑料包装有限公司 Injection molding surface defect identification method
CN115018838A (en) * 2022-08-08 2022-09-06 和诚精密管业(南通)有限公司 Method for identifying pitting defects on surface of oxidized steel pipe material
CN115082683A (en) * 2022-08-22 2022-09-20 南通三信塑胶装备科技股份有限公司 Injection molding defect detection method based on image processing

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112489025A (en) * 2020-12-07 2021-03-12 南京钢铁股份有限公司 Method for identifying pit defects on surface of continuous casting billet
CN114998198A (en) * 2022-04-24 2022-09-02 南通夏克塑料包装有限公司 Injection molding surface defect identification method
CN115018838A (en) * 2022-08-08 2022-09-06 和诚精密管业(南通)有限公司 Method for identifying pitting defects on surface of oxidized steel pipe material
CN115082683A (en) * 2022-08-22 2022-09-20 南通三信塑胶装备科技股份有限公司 Injection molding defect detection method based on image processing

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115511889A (en) * 2022-11-23 2022-12-23 江苏惠汕新能源集团有限公司 Method for detecting welding defects on surface of solar cell panel bracket
CN115661667A (en) * 2022-12-13 2023-01-31 济宁市土哥农业服务有限公司 Method for identifying impurities of descurainia sophia seeds based on computer vision
CN115661667B (en) * 2022-12-13 2023-04-07 济宁市土哥农业服务有限公司 Method for identifying impurities in descurainia sophia seeds based on computer vision
CN116091499A (en) * 2023-04-07 2023-05-09 山东中胜涂料有限公司 Abnormal paint production identification system
CN116597188A (en) * 2023-07-17 2023-08-15 山东北国发展集团有限公司 Vision-based solid waste resource utilization method and system
CN116597188B (en) * 2023-07-17 2023-09-05 山东北国发展集团有限公司 Vision-based solid waste resource utilization method and system
CN116645374A (en) * 2023-07-27 2023-08-25 深圳思谋信息科技有限公司 Point defect detection method, point defect detection device, computer equipment and storage medium
CN116645367A (en) * 2023-07-27 2023-08-25 山东昌啸商贸有限公司 Steel plate cutting quality detection method for high-end manufacturing
CN116645367B (en) * 2023-07-27 2023-12-01 山东昌啸商贸有限公司 Steel plate cutting quality detection method for high-end manufacturing
CN116645374B (en) * 2023-07-27 2024-03-22 深圳思谋信息科技有限公司 Point defect detection method, point defect detection device, computer equipment and storage medium

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