Optical Engineering最新文献

{"title":"Image capturing and stitching system based on scale-invariant feature transform features for untextured and smooth objects","authors":"Chun-Fu Lin, Chen-Wei Su, Chin-Sheng Chen","doi":"10.1117/1.OE.62.11.113103","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113103","url":null,"abstract":"Abstract. Many stitching studies employ improved scale-invariant feature transform (SIFT) or speeded up robust features (SURFs) stitching algorithms, owing to their excellent robustness against variations in scale and rotations of input images. Traditional SIFT-based stitching algorithms suffer from the limitation of having insufficient feature points that can be extracted and matched from untextured and smooth objects, resulting in stitching failure. To overcome this issue, we propose a system that uses a proposed laser pattern projection (LASPP)-pasted texture technique before feature point extraction and description. The proposed system can extract and describe feature points based on SIFT feature extraction techniques. The progressive sample consistency (PROSAC) algorithm was used to remove false matching points and enhance the accuracy in matching feature points. The experimental results clearly revealed the effect of the pattern projected using LASPP on the stitching results. Furthermore, the efficiency of the proposed system, which employed the PROSAC algorithm, in matching feature points, was compared with that of the traditional system, which used the random sample consensus algorithm. Additionally, the stitching quality of the proposed system was compared with that of other SIFT- and SURF-based stitching systems.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"19 1","pages":"113103 - 113103"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139292931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of melt pool and thermal field simulation for wide-band laser cladding","authors":"Bin Hu, Jianhai Han, Xiangpan Li, Junhua Wang","doi":"10.1117/1.OE.62.11.116103","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.116103","url":null,"abstract":"Abstract. The accuracy of thermal analysis modeling for direct energy deposition is compromised if the Marangoni effect is ignored. The anisotropic enhanced thermal conductivity approach can improve the fidelity of the transient finite element (FE) thermal model, but the determination of the enhanced factors is generally based on empirical knowledge or trial and error. In this study, single track cladding experiments were conducted at different process parameters, the cladding process was recorded by an infrared camera, and the melt pool width and length were extracted from the infrared images. The best match enhanced factors were confirmed according to the comparison between the simulated and experimental melt pool sizes. The findings suggest that the best match enhanced factors are not a constant value, but rather vary with changes of process parameters. With the enhanced factors increasing, the peak melt pool temperature drops sharply at first and then tends to be stable. The melt pool width remains almost unchanged, whereas the melt pool length exhibits a slight increase. Laser specific energy was found to be a suitable metric to characterize the convection features and intensity of the melt pool. An empirical model of laser specific energy and enhanced factors was derived through linear regression analysis, which greatly simplified the determination of the enhanced factors. The experimental results showed that the error of the FE thermal model in predicting the melt pool size was less than 6.3%.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"16 1","pages":"116103 - 116103"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139293192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of scene contrast temperature in mid-wave infrared and long-wave infrared","authors":"Shane Jordan, Ronald G. Driggers, Orges Furxhi, Patrick Leslie, Col Cavanaugh, Kyle Renshaw, Eddie L. Jacobs","doi":"10.1117/1.OE.62.11.113107","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113107","url":null,"abstract":"Abstract. One of the primary activities in emissive infrared imager design is the trade on whether to use midwave infrared (MWIR) or longwave infrared (LWIR) in the application. Applications include target acquisition (both target search and target identification), threat warning, aircraft detection, and pilotage. There has been a great deal of work in the characterization of MWIR versus LWIR target signatures. There has been much less work in the characterization of scene (sometimes called background) contrast. The scene contrast of the background can be just as important in the performance of the sensor in an application. A few examples are: (1) a high scene contrast with high clutter contrast can make target search much more difficult, (2) a high scene contrast with image-based navigation can enhance the performance of location estimation, and (3) high scene contrast with mobility sensors can enhance the flying performance of a rotorcraft pilotage system. We discuss the differences observed in scene contrast between MWIR and LWIR bands. This provides a scene contrast characterization for emissive infrared applications. Radiometrically calibrated imagery is acquired with MWIR and LWIR cameras in various environments, and the measured MWIR and LWIR scene contrast is compared. The radiometric comparison is performed in terms of the standard deviation of the scene equivalent blackbody temperature. Comparisons are provided under different conditions, such as rural versus urban and day versus night. This comparison enables the infrared system designer with the means to perform detailed engineering trades.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"40 1","pages":"113107 - 113107"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139294165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive received signal strength-based localization and channel state information estimation model for indoor multiple-input multiple-output visible light communication using the distance vector","authors":"Tran The Son, Vuong Cong Dat, H. Le‐Minh, Zabih Ghassemlooy, Duong Huu Ai, Huynh Cong Phap","doi":"10.1117/1.OE.62.11.118104","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.118104","url":null,"abstract":"Abstract. We propose an adaptive localization and channel state information (CSI) estimation model using the distance vector for indoor multiple-input multiple-output (MIMO) visible light communication (VLC). Under normal conditions, receivers (Rxs) require the CSI of all channels [formed by multiple transmitters (Txs) and multiple Rxs] to recover the original data, and the received signal strength (RSS) obtained from Txs, i.e., light-emitting diodes (LEDs) to predict the Rx’s location. A beacon [or pilot signal (PS)] with CSI is periodically broadcasted from each LED to MIMO Rxs for constructing the CSI matrix and measuring the RSS. However, in an abnormal condition, PSs from one or multiple Txs might not reach Rxs due to shadowing, thus resulting in a failure in positioning and data recovery. To combat this, the proposed model enables the Rx to predict its location without the need for all PSs based on the construction of the distance vectors at Rx. Simulations conducted for two scenarios of user’s mobility, i.e., lattice and random direction mobility, show a low positioning error of ∼0.1 and 0.2 m, respectively. Based on predicted positions, MIMO VLC is capable of fulfilling the CSI matrix and assists the Rx in recovering transmitted data with a very low bit error rate.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"50 1","pages":"118104 - 118104"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139291215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable optical buffer based on VO2/Si hybrid waveguide by optically induced phase transition","authors":"Zhen Yuan, Yi Li, Wenyan Dai, Ke Lin, Weiye He, Haoting Zhang, Chang Xue, Junyi Yan, Jincheng Mei, Jiaqing Zhuang, Xingping Wang","doi":"10.1117/1.OE.62.11.117102","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.117102","url":null,"abstract":"Abstract. A tunable optical buffer composed of a side-coupled racetrack microring resonator (RMRR) sequence and phase change material vanadium dioxide (VO2) films has been designed and simulated with pass-through and drop functions. By optically induced phase transition of VO2, the number of coupled RMRRs is dynamically controlled to realize the required delay time and the ultra-fast response. Simulation results show that the buffer with 12 RMRRs achieves a tunable delay of up to 309.6 ps, a working bandwidth of 306 GHz, and a super-fast response of 0.62 ps. The delay loss and power consumption are 0.012  dB  /  ps and 0.194  mW  /  ps, respectively. These findings suggest a new approach to realizing tunable delay in all-optical networks.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"66 1","pages":"117102 - 117102"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139302547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of high-Q photonic crystal ring resonator incorporating Gaussian distributed inner rods for refractive index sensor","authors":"Uttara Biswas, Jayanta Kumar Rakshit, Chittaranjan Nayak","doi":"10.1117/1.oe.62.11.116101","DOIUrl":"https://doi.org/10.1117/1.oe.62.11.116101","url":null,"abstract":"","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"2 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135162006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constructing high-dynamic-range spectral images for natural scenes","authors":"Z. Ye, Haisong Xu, Yiming Huang, Yuemin Li, Minhang Yang","doi":"10.1117/1.OE.62.11.113105","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113105","url":null,"abstract":"Abstract. The cutting-edge research in high-dynamic-range (HDR) display, such as inverse tone-mapping operators for HDR TV, HDR image quality (IQ) evaluation, and HDR image enhancement, suffer from a lack of reliable training and testing images. To address this problem, we combined the HDR imaging technique with high-accuracy spectral images to construct a first-of-its-kind HDR spectral radiance image. A framework was presented to capture multi-exposure hyperspectral images of HDR outdoor scenes and establish the HDR spectral image. By employing spectrophotometric calibration, the spectral radiance-based HDR images were created. The metadata of the spectral images provide crucial colorimetry information that was absent in the existing datasets. To validate the superiority of the proposed HDR spectral images in typical applications, the spectral sensitivity functions of a camera equipped with a multispectral-filter-array sensor was optimized, and the IQ evaluation results indicate a better adaptability over existing ones. Furthermore, the HDR image augmentation suggests that it is possible to provide a large number of RGB training images for various research objectives based on the proposed images.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"11 1","pages":"113105 - 113105"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139292862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Texture classification of complex vector vortex beams","authors":"Jaiver Chicangana-Cifuentes, V. Rodríguez-Fajardo, C. Rosales‐Guzmán, G. Martínez-Ponce","doi":"10.1117/1.OE.62.11.113109","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113109","url":null,"abstract":"Abstract. Transverse spatial structure associated to complex vector vortex beams (VVBs) is classified through an image texture approach, which is based on Haralick features derived from an azimuthally sensitive gray-level co-occurrence matrix (a-GLCM). Previously, the proposed texture identifier has been tested on azimuthally symmetric digital images presenting an improvement in comparison with conventionally constructed GLCM. Then, considering their suitable spatial symmetry, Laguerre–Gauss mode vector beams were numerically generated to characterize its transverse section. Nonetheless, because of the complex structural information, VVBs are decoupled in three 8-bit grayscale images (channels) corresponding to intensity, orientation, and ellipticity parameters. a-GLCMs and Haralick features for each channel are computed with the aim of quantifying transverse structure evolution as a function of topological charge. Also, image scaling effects are studied to test the approach robustness. Even though it has simplicity, texture analysis based on a-GLCM provides an insight to classify VVB structure.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"189 1","pages":"113109 - 113109"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139295473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial aliasing quantification and analysis of existing imaging sensors: NASA’s Hubble Space Telescope, OrbView-3 OHRIS, and commercial-off-the-shelf camera for autonomous robots","authors":"Jason Mudge, Richard L. Kendrick","doi":"10.1117/1.OE.62.11.113104","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113104","url":null,"abstract":"Abstract. Spatial aliasing in its most pronounced form is seen as a Moiré pattern in (sampled) images. Less dramatically, aliasing is a form of image quality (IQ) degradation and exists at some level within any (sampled) image. More sampling tends to improve IQ due to less aliasing; however, there are drawbacks. Spatial aliasing has been recently quantified by Mudge [Appl. Opt.62(13), 3260–3264 (2023)] for imaging sensors (optics plus detector). This quantification allows a trade to be made between the acceptable aliasing errors imbedded within the (sampled) image and the penalty, or cost, associated with additional sampling, e.g., increased complexity, data throughput and storage, and reduced signal-to-noise ratio for fixed arrays or increased scan time. In this work, we examine several existing and useful imaging sensors along with their imagery and aliasing errors to appreciate how well these existing systems are designed with respect to sampling to better inform how future systems could potentially be improved. Finally, from these analyses, a 2% aliasing error rule is extracted initiating a universal aliasing boundary.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"210 1","pages":"113104 - 113104"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139305682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hold surrounding’s key-you only look once version 7: a real-time pedestrian and vehicle detection algorithm in the low-signal-to-noise ratio infrared image","authors":"Yang Liu, Fulong Yi, Yuhua Ma, Yongfu Wang, Dianhui Wang","doi":"10.1117/1.OE.62.11.118105","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.118105","url":null,"abstract":"Abstract. Compared with visible light imaging technology, infrared optical imaging technology (see Fig. 1) is less affected by weather and illumination and is a potential auxiliary solution method for the future of the autonomous driving system. Based on the above characteristics, this study proposes the hold surrounding’s key (HSK)-you only look once (YOLOv7) algorithm. First, based on the characteristics of the infrared image, this study optimizes the network structure of YOLOv7 and proposes a vehicle and pedestrian detection algorithm based on the improved YOLOv7. Aiming at the problem that the reasoning speed and detection accuracy of pedestrian and vehicle detection algorithms based on infrared images are challenging to balance, occupy large storage space, and are difficult to deploy and run in real-time in low and medium-performance devices, the MPConv is added to replace the Conv structure in YOLOv7. In view of the false detection, missed detection, mutual occlusion and overlap of detected objects, and other situations that the YOLOv7 algorithm is prone to cause in the actual deployment environment easily, a tiny object detection layer is added. At the same time, to solve the problem that infrared optical imaging systems are prone to noise caused by external factors, this study introduces the TRPCA method for image denoising in the preprocessing process of the YOLOv7 algorithm. In the end, the HSK-YOLOv7 algorithm is verified using the self-made infrared traffic object detection dataset and the publicly available FLIR dataset to verify the detection effect of the HSK-YOLOv7 algorithm on near-infrared images and thermal infrared images. The parameter quantity of our algorithm is 37.3M, and the computing throughput is 107.5 GFLOPs. The detection speed on the self-made dataset and FLIR dataset reaches 163 frames per second (FPS) and 71.8 FPS, respectively, and the mAP@0.5 indicator reaches 94.08% and 61.3%, respectively. In general, HSK-YOLOv7 can meet the real-time requirements of the autonomous driving system while ensuring detection accuracy.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"34 1","pages":"118105 - 118105"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139298168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}