针对目前视频拼接技术中的主要问题,即SURF(Speed Up Robust Features)特征提取算法与FLANN(Fast Library or Approximate Nearest Neighbors)特征匹配算法在综采工作面恶劣环境中存在特征点误提取和特征点匹配正确率低的问题,提出一种...针对目前视频拼接技术中的主要问题,即SURF(Speed Up Robust Features)特征提取算法与FLANN(Fast Library or Approximate Nearest Neighbors)特征匹配算法在综采工作面恶劣环境中存在特征点误提取和特征点匹配正确率低的问题,提出一种改进SURF-FLANN的综采工作面视频拼接特征提取与匹配算法。为了提高特征点提取正确率,该方法通过将传统的高斯滤波换为更为先进的双边滤波提取图像中的SURF关键特征点,同时在特征向量中引入特征点4-领域内的特征点描述符信息,从而改进了描述符算子,进一步提高了特征点的描述能力。为了提升特征点匹配速度,提出了R-FLANN(Random Sample Consensus-Fast Library or Approximate Nearest Neighbors)特征匹配算法,该算法利用RANSAC算法获取特征点的匹配先验信息剔除无匹配、误匹配的特征点,从而提高特征点匹配速度。为了验证改进效果,通过消融试验验证了改进SURF-FLANN的特征提取与匹配算法有效提升综采工作面视频图像特征提取和匹配正确率。通过本文方法与SIFT+FLANN,Hairrs与SURF+FLANN的特征提取与匹配算法进行特征点提取与匹配的对比试验,结果表明本文方法特征提取与匹配平均正确率和平均匹配速度最高,分别达到了81.47%和51.47帧/s。通过运用本文方法与SIFT+FLANN,Hairrs与SURF+FLANN的特征提取与匹配算法进行视频图像拼接对比试验,结果表明本文提出的方法在拼接效果清晰度、对比度、熵、拼接速率指标都最好,得到了最佳效果。展开更多
为改善传统算法对量块特征匹配计算大、精度不足的问题,提出一种基于SURF(speed up robust feature)改进的算法。该算法对采集到的图像预处理得到有效匹配区域,筛除无关特征点的干扰;判断矩阵的迹进一步剔除无效点;在欧式距离的基础上...为改善传统算法对量块特征匹配计算大、精度不足的问题,提出一种基于SURF(speed up robust feature)改进的算法。该算法对采集到的图像预处理得到有效匹配区域,筛除无关特征点的干扰;判断矩阵的迹进一步剔除无效点;在欧式距离的基础上得到模型筛选阈值,并运用随机抽样一致(RANSAC)算法进一步提纯匹配。通过实验分析比较,与传统算法相比,改进后算法正确率较高,具有较强鲁棒性。展开更多
针对传统SURF算法(speeded up robust features)在拼接高分辨率无人机航拍图像时运行速度慢、特征匹配率低的特点,提出了一种基于IB-SURF(image block-SURF)技术的无人机图像拼接算法。结合无人机定位定姿系统(position and orientation...针对传统SURF算法(speeded up robust features)在拼接高分辨率无人机航拍图像时运行速度慢、特征匹配率低的特点,提出了一种基于IB-SURF(image block-SURF)技术的无人机图像拼接算法。结合无人机定位定姿系统(position and orientation system,POS)求取图像重叠区域;构造掩模在无人机图像重叠区域检测特征点,减少特征提取时间;借助图像分块(image block,IB)的思想对图像划分网格,精简筛选特征点;引入Neighborhood-KNN(neighborhood-K nearest neighbors)进行特征点匹配,提高图像匹配效率。实验结果表明,IB-SURF算法有较快的运行速度和较高的特征匹配率,平均特征匹配率达到84.3%,特征匹配正确率超过95.1%,为图像高质量拼接提供了技术基础。展开更多
针对目前多数图像水印算法水印的嵌入区域固定不变带来的安全性问题,且水印的抗旋转攻击能力弱,提出一种基于伪Zernike矩和SURF的自适应水印算法。首先,利用SURF(Speed Up Robust Features)算法对图像进行特征提取,然后采用RANSAC(Rando...针对目前多数图像水印算法水印的嵌入区域固定不变带来的安全性问题,且水印的抗旋转攻击能力弱,提出一种基于伪Zernike矩和SURF的自适应水印算法。首先,利用SURF(Speed Up Robust Features)算法对图像进行特征提取,然后采用RANSAC(Random Sample Consensus)算法筛选出稳定的特征点,根据特征点位置构建合适的水印嵌入区域。最后,采用SWT变换和SVD分解将水印信息嵌入在构造区域内。利用伪Zernike矩估计旋转角度对图像进行旋转校正。实验结果表明,该水印算法可以有效地抵抗旋转攻击,水印的安全性得到提高。展开更多
Bivalve aquaculture plays a crucial role in the aquaculture industry due to the economic value of many bivalve species.Understanding the underlying genetic basis of bivalve growth regulation is essential for enhancing...Bivalve aquaculture plays a crucial role in the aquaculture industry due to the economic value of many bivalve species.Understanding the underlying genetic basis of bivalve growth regulation is essential for enhancing germplasm innovation and ensuring sustainable development of the industry.Though numerous candidate genes have been identified,their functional validation remains challenging.Fortunately,the dwarf surf clam(Mulinia lateralis)serves as a promising model organism for investigating genetic mechanisms underlying growth regulation in bivalves.The GWAS study in the Yesso scallop(Patinopecten yessoensis)has pinpointed the E2F3 gene as a key regulator of growth-related traits.However,the specific role of E2F3 in bivalve growth remains unclear.This study aimed to further confirm the regulatory function of the E2F3 gene in the dwarf surf clam through RNA interference experiments.Our results revealed several genes are associated with individual growth and development,including CTS7,HSP70B2,and PGLYRP3,as well as genes involved in lipid metabolism such as FABP2 and FASN.Functional enrichment analysis indicated that E2F3 primarily modulates critical processes like amino acid and lipid metabolism.These findings suggest that E2F3 likely regulates growth in the dwarf surf clam by influencing amino acid and lipid metabolism.Overall,this study advances our understanding on the function of E2F3 gene in growth regulation in bivalves,providing valuable insights for future research in this field.展开更多
The effects of surf zone eddy generated by alongshore currents on the deformation and transport of dye are still poorly understood,and related tracer release experiments are lacking.Therefore,a tracer release laborato...The effects of surf zone eddy generated by alongshore currents on the deformation and transport of dye are still poorly understood,and related tracer release experiments are lacking.Therefore,a tracer release laboratory experiment was conducted under monochromatic,unidirectional incident waves with a large incident angle(30°)on a plane beach with a 1:100 slope in a large wave basin.A charge-coupled device suspended above the basin recorded the dye patch image.The evolution of eddy dye patch was observed and the transport and diffusion were analyzed based on the collected images.Subsequently,a linear instability numerical model was adopted to calculate the perturbation velocity field at the initial stage.The observation and image processing results show that surf zone eddy patches occurred and were separated from the original dye patches.Our numerical analysis results demonstrate that the structure of the perturbation velocity field is consistent with the experimental observations,and that the ejection of eddy patches shoreward or offshore may be ascribed to the double vortex.展开更多
文摘为改善传统算法对量块特征匹配计算大、精度不足的问题,提出一种基于SURF(speed up robust feature)改进的算法。该算法对采集到的图像预处理得到有效匹配区域,筛除无关特征点的干扰;判断矩阵的迹进一步剔除无效点;在欧式距离的基础上得到模型筛选阈值,并运用随机抽样一致(RANSAC)算法进一步提纯匹配。通过实验分析比较,与传统算法相比,改进后算法正确率较高,具有较强鲁棒性。
基金funded by the National Natural Science Foundation of China (No. U2106231)the Key Research and Development Project of Shandong Province (No. 2021 ZLGX03)the National Key Research and Development Program of China (No. 2022YFD2400303)
文摘Bivalve aquaculture plays a crucial role in the aquaculture industry due to the economic value of many bivalve species.Understanding the underlying genetic basis of bivalve growth regulation is essential for enhancing germplasm innovation and ensuring sustainable development of the industry.Though numerous candidate genes have been identified,their functional validation remains challenging.Fortunately,the dwarf surf clam(Mulinia lateralis)serves as a promising model organism for investigating genetic mechanisms underlying growth regulation in bivalves.The GWAS study in the Yesso scallop(Patinopecten yessoensis)has pinpointed the E2F3 gene as a key regulator of growth-related traits.However,the specific role of E2F3 in bivalve growth remains unclear.This study aimed to further confirm the regulatory function of the E2F3 gene in the dwarf surf clam through RNA interference experiments.Our results revealed several genes are associated with individual growth and development,including CTS7,HSP70B2,and PGLYRP3,as well as genes involved in lipid metabolism such as FABP2 and FASN.Functional enrichment analysis indicated that E2F3 primarily modulates critical processes like amino acid and lipid metabolism.These findings suggest that E2F3 likely regulates growth in the dwarf surf clam by influencing amino acid and lipid metabolism.Overall,this study advances our understanding on the function of E2F3 gene in growth regulation in bivalves,providing valuable insights for future research in this field.
基金The open foundation of the State Key Laboratory of Hydraulic Engineering Simulation and Safety under contract No.HESS-2006the Shanxi Province Science Foundation under contract No.202103021224116the research project supported by Shanxi Scholarship Council of China under contract No.2023-067.
文摘The effects of surf zone eddy generated by alongshore currents on the deformation and transport of dye are still poorly understood,and related tracer release experiments are lacking.Therefore,a tracer release laboratory experiment was conducted under monochromatic,unidirectional incident waves with a large incident angle(30°)on a plane beach with a 1:100 slope in a large wave basin.A charge-coupled device suspended above the basin recorded the dye patch image.The evolution of eddy dye patch was observed and the transport and diffusion were analyzed based on the collected images.Subsequently,a linear instability numerical model was adopted to calculate the perturbation velocity field at the initial stage.The observation and image processing results show that surf zone eddy patches occurred and were separated from the original dye patches.Our numerical analysis results demonstrate that the structure of the perturbation velocity field is consistent with the experimental observations,and that the ejection of eddy patches shoreward or offshore may be ascribed to the double vortex.
