搜索到9935篇“ MULTISPECTRAL“的相关文章
基于无人机多光谱数据和氮素空间分异的玉米冠层氮浓度估算
2025年
作物冠层氮素营养的遥感诊断对指导作物精准施氮,提高作物氮效率和产量具有重要意义。本研究针对玉米冠层纵深大影响无人机估算氮浓度精度的问题,基于2022年和2023年不同氮肥运筹处理下田间无人机多光谱数据和氮浓度实测数据,分析玉米冠层氮浓度空间分布特征,并利用随机森林算法确定估算冠层氮浓度的有效叶层。进一步结合随机森林算法和多光谱植被指数构建有效叶层氮浓度估算模型,最终将有效叶层氮浓度转换到冠层尺度实现冠层氮浓度的估算。结果表明:(1)九叶展期和大喇叭口期玉米冠层氮浓度表现为上层叶片>中层叶片>下层叶片,吐丝期和乳熟期表现为中层叶片>上层叶片>下层叶片。(2)各时期估算冠层氮浓度的有效叶层分别为下层、中层、中层和中层。与支持向量回归模型相比,随机森林回归估算冠层氮浓度的精度较高。(3)结合随机森林算法,基于有效叶层氮浓度估算冠层氮浓度的平均RMSE、NRMSE和MAE分别为0.10%、4.41%和0.07%,而直接基于植被指数估算冠层氮浓度的平均RMSE、NRMSE和MAE分别为0.19%、9.00%和0.15%。综上,玉米冠层氮浓度存在空间分异特征,估算冠层氮浓度时考虑基于随机森林和植被指数估算的有效叶层氮浓度能明显提高冠层氮浓度的估算精度。本研究确定的考虑空间分异的冠层氮浓度估算框架可为玉米氮素营养实时诊断提供理论支撑。
郝琪陈天陆王富贵王振白岚方王永强王志刚
关键词:玉米多光谱数据
基于多光谱和高光谱的茶树越冬期REC、SPAD和MDA预测模型
2025年
抗寒生理指标的测定是评价茶树抗寒性的重要途径。传统上,茶树抗寒性的评价方法主要是通过测定茶树在低温胁迫下的理化参数。然而,这些方法不仅费时费力,而且具有破坏性。该研究建立了一种基于多光谱和高光谱成像技术的茶树抗寒性REC、SPAD、MDA预测模型。首先,采集了低温胁迫下32份育种材料的多光谱与高光谱图像,并测定相应茶树叶片的REC、SPAD、MDA、SP和SS含量。其次,对其中的高光谱图像数据采用MSC、SNV、S-G、1-D和2-D五种方法进行光谱预处理,采用UVE和SPA两种方法筛选特征波段。最后,分别对多光谱和高光谱数据采用SVM、RF和PLS算法建立茶树抗寒性REC、SPAD、MDA预测模型。结果表明,(1)MSC、SNV、S-G、1-D和2-D联合预处理后的光谱更加稳定,峰谷更加突出,模型的准确性和可靠性更高;(2)UVE算法筛选的特征波段数量最多,而SPA算法筛选的特征波段数量最少,更适合高光谱数据建立回归模型;(3)RF模型在多光谱成像预测叶片的REC(R_(p)=0.7352,RMSEP=0.0771)、SPAD(R_(p)=0.5029,RMSEP=6.6818)和MDA含量(R_(p)=0.7846,RMSEP=8.8853)方面具有最高的精度;SPA-SVM模型在高光谱成像预测叶片的SPAD(R_(p)=0.7349,RMSEP=4.1546)和MDA(R_(p)=0.6858,RMSEP=8.5488)方面具有最高的精度,SPA-PLS模型在预测REC(R_(p)=0.6298,RMSEP=0.0669)方面具有最高的精度。因此,基于多光谱、高光谱成像和机器学习算法的REC、SPAD、MDA预测模型提供了一种准确、无损和高效的方法,对茶树抗寒性评价具有重要意义。
徐阳毛艺霖李赫王玉王双双钱文俊丁兆堂范凯
关键词:茶树多光谱成像高光谱成像抗寒性
Multispectral point cloud superpoint segmentation
2024年
The multitude of airborne point clouds limits the point cloud processing efficiency.Superpoints are grouped based on similar points,which can effectively alleviate the demand for computing resources and improve processing efficiency.However,existing superpoint segmentation methods focus only on local geometric structures,resulting in inconsistent spectral features of points within a superpoint.Such feature inconsistencies degrade the performance of subsequent tasks.Thus,this study proposes a novel Superpoint Segmentation method that jointly utilizes spatial Geometric and Spectral Information for multispectral point cloud superpoint segmentation(GSI-SS).Specifically,a similarity metric that combines spatial geometry and spectral information is proposed to facilitate the consistency of geometric structures and object attributes within segmented superpoints.Following the formation of the primary superpoints,an intersuperpoint pointexchange mechanism that maximizes feature consistency within the final superpoints is proposed.Experiments are conducted on two real multispectral point cloud datasets,and the proposed method achieved higher recall,precision,F score,and lower global consistency and feature classification errors.The experimental results demonstrate the superiority of the proposed GSI-SS over several state-of-the-art methods.
WANG QingWangWANG MingYeZHANG ZiFengSONG JianZENG KaiSHEN TaoGU YanFeng
关键词:OVER-SEGMENTATION
Lightweight Cross-Modal Multispectral Pedestrian Detection Based on Spatial Reweighted Attention Mechanism
2024年
Multispectral pedestrian detection technology leverages infrared images to provide reliable information for visible light images, demonstrating significant advantages in low-light conditions and background occlusion scenarios. However, while continuously improving cross-modal feature extraction and fusion, ensuring the model’s detection speed is also a challenging issue. We have devised a deep learning network model for cross-modal pedestrian detection based on Resnet50, aiming to focus on more reliable features and enhance the model’s detection efficiency. This model employs a spatial attention mechanism to reweight the input visible light and infrared image data, enhancing the model’s focus on different spatial positions and sharing the weighted feature data across different modalities, thereby reducing the interference of multi-modal features. Subsequently, lightweight modules with depthwise separable convolution are incorporated to reduce the model’s parameter count and computational load through channel-wise and point-wise convolutions. The network model algorithm proposed in this paper was experimentally validated on the publicly available KAIST dataset and compared with other existing methods. The experimental results demonstrate that our approach achieves favorable performance in various complex environments, affirming the effectiveness of the multispectral pedestrian detection technology proposed in this paper.
Lujuan DengRuochong FuZuhe LiBoyi LiuMengze XueYuhao Cui
Relative peripheral refraction in school children with different refractive errors using a novel multispectral refraction topographer
2024年
AIM:To compare relative peripheral refraction(RPR)in Chinese school children with different refractive errors using multispectral refraction topography(MRT).METHODS:A total of 713 eyes of primary school children[172 emmetropia(E),429 low myopia(LM),80 moderate myopia(MM),and 32 low hypermetropia(LH)]aged 10 to 13y were analyzed.RPRs were measured using MRT without mydriasis.MRT results showed RPR at 0-15°(RPR 0-15),15°-30°(RPR 15-30),and 30°-45°(RPR 30-45)annular in the inferior(RPR-I),superior(RPR-S),nasal(RPR-N),and temporal(RPR-T)quadrants.Spherical equivalent(SE)was detected and calculated using an autorefractor.RESULTS:There were significant differences of RPR 15-30 between groups MM[0.02(-0.12;0.18)]and LH[-0.13(-0.36;0.12)](P<0.05),MM and E[-0.06(-0.20;0.10)](P<0.05),and LM[-0.02(-0.15;0.15)]and E(P<0.05).There were also significant differences of RPR 30-45 between groups MM[0.45(0.18;0.74)]and E[0.29(-0.09;0.67)](P<0.05),and LM[0.44(0.14;0.76)]and E(P<0.001).RPR values increased from the hyperopic to medium myopic group in each annular.There were significant differences of RPR-S between groups MM[-0.02(-0.60;0.30)]and E[-0.44(-0.89;-0.04)](P<0.001),and LM[-0.28(-0.71;0.12)]and E(P<0.05).There were also significant differences of RPR-T between groups MM[0.37(0.21;0.78)]and LH[0.14(-0.52;0.50)](P<0.05),LM[0.41(0.06;0.84)]and LH(P<0.05),and LM and E[0.29(-0.10;0.68),P<0.05].A Spearman’s correlation analysis showed a negative correlation between RPR and SE in the 15°-30°(P=0.005),30°-45°(P<0.05)annular(P=0.002),superior(P<0.001),and temporal(P=0.001)quadrants.CONCLUSION:Without pupil dilation,values for RPR 15-30,30-45,RPR-S,and T shows significant differences between myopic eyes and emmetropia,and the differences are negatively correlated with SE.
Hui-Ling HuSerena Zhe-Chuang LiAi-Ying FengHao-Xi ZhongJing-Feng MuMei-Zhou Liu
关键词:MYOPIA
An unmanned ground vehicle phenotyping-based method to generate three-dimensional multispectral point clouds for deciphering spatial heterogeneity in plant traits
2024年
Fusing three-dimensional(3D)and multispectral(MS)imaging data holds promise for high-throughput and comprehensive plant phenotyping to decipher genome-to-phenome knowledge.Acquiring high-quality 3D MS point clouds(3DMPCs)of plants remains challenging because of poor 3D data quality and limited radiometric calibration methods for plants with a complex canopy structure.Here,we present a novel 3D spatial–spectral data fusion approach to collect high-quality 3DMPCs of plants by integrating the next-best-view planning for adaptive data acquisition and neural reference field(NeREF)for radiometric calibration.This approach was used to acquire 3DMPCs of perilla,tomato,and rapeseed plants with diverse plant architecture and leaf morphological features evaluated by the accuracy of chlorophyll content and equivalent water thickness(EWT)estimation.The results showed that the completeness of plant point clouds collected by this approach was improved by an average of 23.6%compared with the fixed viewpoints alone.The NeREF-based radiometric calibration with the hemispherical reference outperformed the conventional calibration method by reducing the root mean square error(RMSE)of 58.93%for extracted reflectance spectra.The RMSE for chlorophyll content and EWT predictions decreased by 21.25%and 14.13%using partial least squares regression with the generated 3DMPCs.Collectively,our study provides an effective and efficient way to collect high-quality 3DMPCs of plants under natural light conditions,which improves the accuracy and comprehensiveness of phenotyping plant morphological and physiological traits,and thus will facilitate plant biology and genetic studies as well as crop breeding.
Pengyao XieZhihong MaRuiming DuXin YangYu JiangHaiyan Cen
One-year results for myopia control of orthokeratology with different back optic zone diameters: a randomized trial using a novel multispectral-based topographer被引量:1
2024年
AIM:To present the 1-year results of a prospective cohort study investigating the efficacy,potential mechanism,and safety of orthokeratology(ortho-k)with different back optic zone diameters(BOZD)for myopia control in children.METHODS:This randomized clinical study was performed between Dec.2020 and Dec.2021.Participants were randomly assigned to three groups wearing ortho-k:5 mm BOZD(5-MM group),5.5 mm BOZD(5.5-MM group),and 6 mm BOZD(6-MM group).The 1-year data were recorded,including axial length,relative peripheral refraction(RPR,measured by multispectral refractive topography,MRT),and visual quality.The contrast sensitivity(CS)was evaluated by CSV-1000 instrument with spatial frequencies of 3,6,12,and 18 cycles/degree(c/d);the corneal higher-order aberrations(HOAs)were measured by iTrace aberration analyzer.The one-way ANOVA was performed to assess the differences between the three groups.The correlation between the change in AL and RPR was calculated by Pearson’s correlation coefficient.RESULTS:The 1-year results of 20,21,and 21 subjects in the 5-MM,5.5-MM,and 6-MM groups,respectively,were presented.There were no statistical differences in baseline age,sex,or ocular parameters between the three groups(all P>0.05).At the 1-year visit,the 5-MM group had lower axial elongation than the 6-MM group(0.07±0.09 vs 0.18±0.11 mm,P=0.001).The 5-MM group had more myopic total RPR(TRPR,P=0.014),with RPR in the 15°–30°(RPR 15–30,P=0.015),30°–45°(RPR 30–45,P=0.011),temporal(RPR-T,P=0.008),and nasal area(RPR-N,P<0.001)than the 6-MM group.RPR 15–30 in the 5.5-MM group was more myopic than that in the 6-MM group(P=0.002),and RPR-N in the 5-MM group was more myopic than that in the 5.5-MM group(P<0.001).There were positive correlations between the axial elongation and the change in TRPR(r=0.756,P<0.001),RPR 15–30(r=0.364,P=0.004),RPR 30–45(r=0.306,P=0.016),and RPR-N(r=0.253,P=0.047).The CS decreased at 3 c/d(P<0.001),and the corneal HOAs increased in the 5-MM group(P=0.030).CONCLUSION:Ortho-k with 5 mm BO
Wen-Ting TangXiang-Ning LuoWen-Jing ZhaoJia LiaoXin-Yue XuHui-Dan ZhangLi Zhang
关键词:ORTHOKERATOLOGYMYOPIA
多光谱目标检测综述
2024年
多光谱目标检测技术是一种利用不同波长光谱的信息来检测和识别目标的方法。该技术结合了可见光、红外、热成像等不同光谱的数据,通过融合多光谱数据来提高目标检测的精确度和鲁棒性。在低光或其他具有挑战性的环境中,多光谱目标检测表现出优越的性能。该技术在夜视监控、气象观测、农业、环境监测等领域有着广泛的应用。本文首先介绍了多光谱图像的定义、获取方式及常用数据集;其次,介绍了多光谱目标检测算法的分类并给出相关算法示例;再次,介绍了多光谱目标检测的应用,重点讨论了多光谱目标检测在行人检测、农业、环境监测等领域的具体应用案例;最后,探讨了多光谱目标检测未来的发展方向。
王元喆梁腾飞曾宇乔金一李浥东
关键词:多光谱目标检测特征提取图像融合
基于改进YOLOX的多光谱行人检测算法
2024年
现有的多光谱行人检测算法大多是基于Faster R-CNN的两阶段检测或设置了锚框机制的一阶段检测,此类模型存在推理速度慢,检测准确率低等不足.为此,本文设计出一种基于一阶段无锚框检查算法YOLOX的多光谱行人检测算法.该算法将多模态特征提取解耦为特性特征提取和共性特征提取两阶段.针对基准特性特征提取网络学习能力不足、提取的语义信息和纹理细节信息不够丰富的问题,本文设计出一种多尺度特征增强(Multi-scale Feature Enhancement,MFE)模块,该模块可提取出特性特征图中丰富的语义和纹理细节信息.此外,本文使用基于差异性的特征融合方法来充分捕获两种模态的差异性特征信息.为证实本文方法的有效性和可行性,本文在KAIST数据集和FLIR数据集上进行了实验验证,实验结果表明本文所提方法可显著提高多光谱行人检测的性能.
方康黄琴王克琪靳帅刘畅钱宇华钱宇华
关键词:多光谱行人检测多尺度
基于深度学习的烟丝杂物多光谱检测技术
2024年
针对烟丝杂物剔除问题,提出了基于深度学习的烟丝杂物多光谱检测方法。首先设计了总体检测方案和检测系统,搭建了多光谱实验验证系统。利用高光谱成像技术和深度学习方法对烟丝中的非烟物质进行分类识别,针对杂物和烟丝对光的反射特性不同,利用光谱相机拍摄不同波段的图片,分别比较机器学习算法和深度学习算法进行的训练与分类,通过GoogLeNet深度学习算法识别烟丝中的杂物。结果表明:检测识别与剔除正确率为99.5%,证实了检测技术的高效性和准确性。
李安虎万亚明吴玉生

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杨金库
作品数:9被引量:2H指数:1
供职机构:西北工业大学
研究主题:逆变换 多光谱图像 二维EMD 图像融合 自适应
郭雷
作品数:585被引量:1,706H指数:19
供职机构:西北工业大学
研究主题:图像 图像融合 遥感图像 图像处理 图像检索
陈舜儿
作品数:79被引量:238H指数:8
供职机构:暨南大学
研究主题:无源光网络 以太网 光纤光栅 光纤光栅滤波器 以太无源光网络
崔笛
作品数:16被引量:45H指数:3
供职机构:中国农业大学
研究主题:作物冠层 作物长势 光谱学 氮含量 光谱分析
韩冬
作品数:27被引量:50H指数:3
供职机构:清华大学
研究主题:气隙 探测器 水沙 绝缘件 绝缘层