由于水的吸收和悬浮粒子的散射作用,水下图像出现色偏、对比度降低以及细节模糊等问题,影响水下视觉同步定位与地图构建(Simultaneous localization and mapping,SLAM)前端特征提取和特征匹配。针对上述问题,提出一种用于水下视觉SLAM...由于水的吸收和悬浮粒子的散射作用,水下图像出现色偏、对比度降低以及细节模糊等问题,影响水下视觉同步定位与地图构建(Simultaneous localization and mapping,SLAM)前端特征提取和特征匹配。针对上述问题,提出一种用于水下视觉SLAM前端的多尺度融合与细节突显的图像增强算法。首先,提出一种改进颜色通道补偿的颜色校正方法,用于校正水下图像色偏;其次,利用曝光融合框架对颜色校正的水下图像对比度进行增强;然后,将颜色校正图像和对比度增强图像进行多尺度融合;最后,采用非锐化掩模对融合图像进行细节突显,进而得到视觉效果较好的增强图像。实验结果表明,与其他算法相比,该算法处理后的水下图像在颜色平衡、对比度、细节以及清晰度等方面的效果较好,同时还增加了特征点和特征匹配对数,显著改善了水下视觉SLAM前端的特征提取和特征匹配。展开更多
3D laser scanning technology is widely used in underground openings for high-precision,rapid,and nondestructive structural evaluations.Segmenting large 3D point cloud datasets,particularly in coal mine roadways with m...3D laser scanning technology is widely used in underground openings for high-precision,rapid,and nondestructive structural evaluations.Segmenting large 3D point cloud datasets,particularly in coal mine roadways with multi-scale targets,remains challenging.This paper proposes an enhanced segmentation method integrating improved PointNet++with a coverage-voted strategy.The coverage-voted strategy reduces data while preserving multi-scale target topology.The segmentation is achieved using an enhanced PointNet++algorithm with a normalization preprocessing head,resulting in a 94%accuracy for common supporting components.Ablation experiments show that the preprocessing head and coverage strategies increase segmentation accuracy by 20%and 2%,respectively,and improve Intersection over Union(IoU)for bearing plate segmentation by 58%and 20%.The accuracy of the current pretraining segmentation model may be affected by variations in surface support components,but it can be readily enhanced through re-optimization with additional labeled point cloud data.This proposed method,combined with a previously developed machine learning model that links rock bolt load and the deformation field of its bearing plate,provides a robust technique for simultaneously measuring the load of multiple rock bolts in a single laser scan.展开更多
摘要由于水的吸收和悬浮粒子的散射作用,水下图像出现色偏、对比度降低以及细节模糊等问题,影响水下视觉同步定位与地图构建(Simultaneous localization and mapping,SLAM)前端特征提取和特征匹配。针对上述问题,提出一种用于水下视觉SLAM前端的多尺度融合与细节突显的图像增强算法。首先,提出一种改进颜色通道补偿的颜色校正方法,用于校正水下图像色偏;其次,利用曝光融合框架对颜色校正的水下图像对比度进行增强;然后,将颜色校正图像和对比度增强图像进行多尺度融合;最后,采用非锐化掩模对融合图像进行细节突显,进而得到视觉效果较好的增强图像。实验结果表明,与其他算法相比,该算法处理后的水下图像在颜色平衡、对比度、细节以及清晰度等方面的效果较好,同时还增加了特征点和特征匹配对数,显著改善了水下视觉SLAM前端的特征提取和特征匹配。
基金supported by the National Natural Science Foundation of China(Grant Nos.52304139,52325403)the CCTEG Coal Mining Research Institute funding(Grant No.KCYJY-2024-MS-10).
摘要3D laser scanning technology is widely used in underground openings for high-precision,rapid,and nondestructive structural evaluations.Segmenting large 3D point cloud datasets,particularly in coal mine roadways with multi-scale targets,remains challenging.This paper proposes an enhanced segmentation method integrating improved PointNet++with a coverage-voted strategy.The coverage-voted strategy reduces data while preserving multi-scale target topology.The segmentation is achieved using an enhanced PointNet++algorithm with a normalization preprocessing head,resulting in a 94%accuracy for common supporting components.Ablation experiments show that the preprocessing head and coverage strategies increase segmentation accuracy by 20%and 2%,respectively,and improve Intersection over Union(IoU)for bearing plate segmentation by 58%and 20%.The accuracy of the current pretraining segmentation model may be affected by variations in surface support components,but it can be readily enhanced through re-optimization with additional labeled point cloud data.This proposed method,combined with a previously developed machine learning model that links rock bolt load and the deformation field of its bearing plate,provides a robust technique for simultaneously measuring the load of multiple rock bolts in a single laser scan.