{"title":"多视场光场相机在LPBF制造过程中的高动态范围成像","authors":"Xiuhua Li , Hui Li , Shengnan Shen , Wei Xiong","doi":"10.1016/j.optlastec.2025.113469","DOIUrl":null,"url":null,"abstract":"<div><div>The laser powder bed fusion (LPBF) additive manufacturing (AM) process, subjected to extreme temperature variations from the high-power laser, exhibits significant brightness differences that traditional imaging methods struggle to capture details of LPBF manufacturing process, leading to challenges in monitoring and optimizing the AM process. This paper develops a novel method of light-field-based high dynamic range imaging (LFHDRI) for LPBF manufacturing process. A light field (LF) Bayer model is applied to extract images from the red (R), green (G), and blue (B) channels. The R channel image during LPBF process is processed using k-means clustering to segment low-light and high-light regions, which are then fused with the B and G channels to reconstruct the high dynamic range (HDR) image. The effectiveness of the LFHDRI method is validated using a steel ruler, with results showing a reduction of the spatial-spectral entropy-based quality (SSEQ) by approximately 50 %, while feature pixel points increase by more than twofold. Comparative experiment on LPBF manufacturing processes, including parts, powder layers, sputter, and melt pools indicates that both the metrics of the SSEQ and the natural image quality evaluator (NIQE) applied to the HDR images obtained by LFHDRI confirm its effectiveness. More features are effectively extracted on the HDR images during LPBF manufacturing process, indicating that image details are effectively enhanced by the LFHDRI. The proposed LFHDRI method addresses the issue of image quality degradation caused by the extreme brightness fluctuations in the LPBF manufacturing process, thereby improving the accuracy of surface defect monitoring.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113469"},"PeriodicalIF":5.0000,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"High dynamic range imaging of LPBF manufacturing process by multi-view light field camera\",\"authors\":\"Xiuhua Li , Hui Li , Shengnan Shen , Wei Xiong\",\"doi\":\"10.1016/j.optlastec.2025.113469\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The laser powder bed fusion (LPBF) additive manufacturing (AM) process, subjected to extreme temperature variations from the high-power laser, exhibits significant brightness differences that traditional imaging methods struggle to capture details of LPBF manufacturing process, leading to challenges in monitoring and optimizing the AM process. This paper develops a novel method of light-field-based high dynamic range imaging (LFHDRI) for LPBF manufacturing process. A light field (LF) Bayer model is applied to extract images from the red (R), green (G), and blue (B) channels. The R channel image during LPBF process is processed using k-means clustering to segment low-light and high-light regions, which are then fused with the B and G channels to reconstruct the high dynamic range (HDR) image. The effectiveness of the LFHDRI method is validated using a steel ruler, with results showing a reduction of the spatial-spectral entropy-based quality (SSEQ) by approximately 50 %, while feature pixel points increase by more than twofold. Comparative experiment on LPBF manufacturing processes, including parts, powder layers, sputter, and melt pools indicates that both the metrics of the SSEQ and the natural image quality evaluator (NIQE) applied to the HDR images obtained by LFHDRI confirm its effectiveness. More features are effectively extracted on the HDR images during LPBF manufacturing process, indicating that image details are effectively enhanced by the LFHDRI. The proposed LFHDRI method addresses the issue of image quality degradation caused by the extreme brightness fluctuations in the LPBF manufacturing process, thereby improving the accuracy of surface defect monitoring.</div></div>\",\"PeriodicalId\":19511,\"journal\":{\"name\":\"Optics and Laser Technology\",\"volume\":\"192 \",\"pages\":\"Article 113469\"},\"PeriodicalIF\":5.0000,\"publicationDate\":\"2025-07-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Optics and Laser Technology\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0030399225010606\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"OPTICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Optics and Laser Technology","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0030399225010606","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"OPTICS","Score":null,"Total":0}
High dynamic range imaging of LPBF manufacturing process by multi-view light field camera
The laser powder bed fusion (LPBF) additive manufacturing (AM) process, subjected to extreme temperature variations from the high-power laser, exhibits significant brightness differences that traditional imaging methods struggle to capture details of LPBF manufacturing process, leading to challenges in monitoring and optimizing the AM process. This paper develops a novel method of light-field-based high dynamic range imaging (LFHDRI) for LPBF manufacturing process. A light field (LF) Bayer model is applied to extract images from the red (R), green (G), and blue (B) channels. The R channel image during LPBF process is processed using k-means clustering to segment low-light and high-light regions, which are then fused with the B and G channels to reconstruct the high dynamic range (HDR) image. The effectiveness of the LFHDRI method is validated using a steel ruler, with results showing a reduction of the spatial-spectral entropy-based quality (SSEQ) by approximately 50 %, while feature pixel points increase by more than twofold. Comparative experiment on LPBF manufacturing processes, including parts, powder layers, sputter, and melt pools indicates that both the metrics of the SSEQ and the natural image quality evaluator (NIQE) applied to the HDR images obtained by LFHDRI confirm its effectiveness. More features are effectively extracted on the HDR images during LPBF manufacturing process, indicating that image details are effectively enhanced by the LFHDRI. The proposed LFHDRI method addresses the issue of image quality degradation caused by the extreme brightness fluctuations in the LPBF manufacturing process, thereby improving the accuracy of surface defect monitoring.
期刊介绍:
Optics & Laser Technology aims to provide a vehicle for the publication of a broad range of high quality research and review papers in those fields of scientific and engineering research appertaining to the development and application of the technology of optics and lasers. Papers describing original work in these areas are submitted to rigorous refereeing prior to acceptance for publication.
The scope of Optics & Laser Technology encompasses, but is not restricted to, the following areas:
•development in all types of lasers
•developments in optoelectronic devices and photonics
•developments in new photonics and optical concepts
•developments in conventional optics, optical instruments and components
•techniques of optical metrology, including interferometry and optical fibre sensors
•LIDAR and other non-contact optical measurement techniques, including optical methods in heat and fluid flow
•applications of lasers to materials processing, optical NDT display (including holography) and optical communication
•research and development in the field of laser safety including studies of hazards resulting from the applications of lasers (laser safety, hazards of laser fume)
•developments in optical computing and optical information processing
•developments in new optical materials
•developments in new optical characterization methods and techniques
•developments in quantum optics
•developments in light assisted micro and nanofabrication methods and techniques
•developments in nanophotonics and biophotonics
•developments in imaging processing and systems