基于优化SIFT算法的农田航拍全景图像快速拼接  

Fast stitching for the farmland aerial panoramic images based on optimized SIFT algorithm

作　　者：刘媛媛[1,3] 何铭 王跃勇 孙宇 高雪冰 LIU Yuanyuan;HE Ming;WANG Yueyong;SUN Yu;GAO Xuebing(College of Information Technology,Jilin Agricultural University,Changchun 130118,China;College of Engineering and Technology,Jilin Agricultural University,Changchun 130118,China;Institute of Intelligent Agriculture,Jilin Agricultural University,Changchun 130118,China)

机构地区：[1]吉林农业大学信息技术学院,长春130118 [2]吉林农业大学工程技术学院,长春130118 [3]吉林农业大学智慧农业研究院,长春130118

出　　处：《农业工程学报》2023年第1期117-125,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(42001256);吉林省科技厅技术创新引导项目(20220402023GH);吉林省科技厅重点科技项目(20230202039NC,20220203004SF);吉林省发展和改革委员会创新项目(2019C054);吉林省教育厅科学技术研究项目(JJKH20220339KJ)。

摘　　要：为了快速准确获取大面积农田图像信息,提高保护性耕作秸秆还田监测效率和准确性,该研究提出一种基于优化SIFT(scale-invariant feature transform)算法的农田航拍全景图像快速拼接方法。首先对高分辨率图像进行降采样处理,针对图像的重叠区域进行有效检测;然后采用基于梯度归一化的特征描述符对特征点进行匹配,同时通过渐进样本一致算法去除误匹配,精准计算拼接转换模型;最后采用基于最佳拼接线的多分辨率融合算法进行图像融合,得到全景拼接图像。试验结果表明:该文方法在图像配准阶段与传统SIFT算法和SURF(speeded up robust feature)算法相比,特征点数量分别减少了97%和90%,运行时间减少了94%和69%,平均匹配效率为65.17%,约为SIFT算法的4倍,SURF算法的9倍;与APAP(ss-projective-as-possible)、SPHP(shape-preserving half-projective)和AANAP(adaptive as-natural-as-possible)算法相比,该方法拼接图像的信息熵、平均梯度和图像对比度均有明显提高。与传统方法相比,该文分层拼接方法提高了全景拼接图像的清晰度和融合效果,解决了传统方法中出现的错位和重影问题,其中全景图像的信息熵、平均梯度小幅提高,对比度明显提高,拼接时间大约缩短了90%以上。研究结果可为保护性耕作秸秆还田监测提供科学参考。Straw mulching has been a common measure for black land conservation in the northeastern plains of China.It is a great significance of an effective solution to reduce soil erosion for environmental protection and sustainable development in modern agriculture.However,it is difficult to calculate the coverage rate at one time,due to the wide area of crop cultivation.Therefore,it is a high demand for the rapid acquisition of image information on a large area of farmland,in order to improve the efficiency and accuracy of straw mulching.Fortunately,aerial drone images and videos can be widely used in various fields,such as agricultural monitoring,weather forecasting,and geographic mapping.Among them,the application of remote sensing technology focuses mainly on the crops and soil in agriculture.The spectral patterns of the ground can be utilized to monitor the crops and soil in the field.Specifically,the spectral characteristics of the ground are used to monitor the growth of crops,crop quality,crop pests,and diseases.The high-resolution images can be collected by unmanned aerial vehicle(UAV)aerial photography.The panoramic stitching can be selected for rapid and accurate access to the large-area farmland image information.Therefore,it is of great practical significance to agricultural intelligence,particularly for the high efficiency and accuracy of straw cover monitoring of conservation tillage.In this study,a fast-stitching method was proposed for the aerial panoramic images of the fields using the optimized scale-invariant feature transform(SIFT)algorithm.Firstly,the high-resolution image was down-sampled to effectively detect the overlapping regions of the image.The gradient normalization-based feature descriptors were then used to match the feature points.The false matches were removed by the progressive sample consistency algorithm,in order to accurately calculate the stitching conversion model.Finally,the multi-resolution fusion algorithm was used for the high-quality stitched image using the best stitching li

关 键 词：无人机 图像处理 全景拼接 SIFT算子 特征点匹配 图像融合 

分 类 号：TP751.1[自动化与计算机技术—检测技术与自动化装置]