## 6 Conclusions  
This article proposes a real-time online measurement system for the size of the cross-cutting board during the transverse board straightening process, which has been successfully applied in industrial sites. The main content of this measurement system is as follows:  
1. In order to address the industrial environment, industrial cameras need to capture images of cross-cutting boards at a certain angle. A visual inspection coordinate transformation model suitable for the industrial field has been established, which can effectively reduce detection errors caused by camera tilt.
2. Aiming at the influence of environmental factors such as dust and iron scrap in the industrial site, this paper developed a series filter based on morphological processing to effectively remove the noise in the field environment by comparing the existing filtering techniques such as median filtering, mean filtering, and Gaussian filtering.
3. According to the dynamic characteristics of the production process of cross-cutting boards, this article adopts the method of deep learning to achieve the accurate extraction of the edge contour of cross-cutting boards.
4. The article proposes a novel edge intersection extraction algorithm based on the line fitting and least squares methods. It fits the extracted edge contours with straight lines, obtains the optimal \(k\) and \(b\) through the least squares method, and then calculates the edge intersections using a pairwise line intersection model.
5. The article proposes to calculate the dimensions of the cross-cutting board based on the coordinates of its four intersection points. The length detection error is \(\leq\)\(\pm\)25 mm,  
Figure 22: Quality evaluation results.  
and the width detection error is \(\leq\)\(\pm\)2 mm. The diagonal detection results are good, which meets the requirements for on-site production.
6. The measurement system also has certain limitations. It can only measure cross-cutting boards with a length of less than 10,000 mm. If the length exceeds 10,000 mm, the field of view of the measurement system will not be able to fully cover the cross-cutting boards. In the future, if this problem is to be solved, it is necessary to improve the algorithm of the measurement system and add a fast image stitching algorithm to achieve the measurement of longer cross-cutting boards.  
Conceptualization, S.G. and Y.P.; methodology, S.G. and Y.P.; software, S.G., W.Z and L.H.; validation, S.G., Y.P. and J.S.; formal analysis, Y.P. and J.S.; investigation, S.G., W.Z., L.H., Y.P. and J.S.; resources, S.G., Y.P. and J.S.; data curation, S.G., W.Z. and L.H.; writing--original draft preparation, S.G. and Y.P.; writing--review and editing, S.G., W.Z., L.H., Y.P. and J.S.; visualization, S.G., W.Z. and L.H.; supervision, Y.P. and J.S.; project administration, Y.P. and J.S.; funding acquisition, Y.P. All authors have read and agreed to the published version of the manuscript.  
This work was supported by Regional Joint Funds of the National Natural Science Foundation of China (U20A20289); Innovative Talents International Cooperative Training Project of China Scholarship Council (CXM20240010); The General Program of National Natural Science Foundation of China (52075471); Innovation Capacity Enhancement Program of Hebei Province (24461901D).  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflict of interest.