inch是什么单位
nuscenes数据读取和解析
1.nuScenes数据集标注格式的说明:
2.根据json⽂件进⾏读取数据路径
3.根据数据路径读取点云数据
4.官⽅api说明
坐标系说明：世界坐标系的轴的⽅向与IMU坐标系的轴的⽅向相同，所以如果需要将点云数据转换到世界坐标系,⾸先需要将点云数据转到IMU，然后再从IMU转到世界坐标系.
在 ('sample_data', sample_json['data'][ nsor]时，会返回对应的nsor_sample_data_json数据
结果如:
英语考试种类japaneschoolchild21sample_data {
"token": <str> -- Unique record identifier.
"sample_token": <str> -- Foreign key. Sample to which this sample_data is associated.
"ego_po_token": <str> -- Foreign key.
"calibrated_nsor_token": <str> -- Foreign key.
"filename": <str> -- Relative path to data-blob on disk.russia
"fileformat": <str> -- Data file format.
"width": <int> -- If the sample data is an image, this is the image width in pixels.
"height": <int> -- If the sample data is an image, this is the image height in pixels.
"timestamp": <int> -- Unix time stamp.
"is_key_frame": <bool> -- True if sample_data is part of key_frame, el Fal.
"next": <str> -- Foreign key. Sample data from the same nsor that follows this in time. Empty if end of scene.
teo
"prev": <str> -- Foreign key. Sample data from the same nsor that precedes this in time. Empty if start of scene.
}点钟
然后根据('calibrated_nsor', nsor_sample_data_json['calibrated_nsor_token'])获取对应的calibrated_nsor_json ⽂件，结果如
calibrated_nsor {
"token": <str> -- Unique record identifier.
"nsor_token": <str> -- Foreign key pointing to the nsor type.
"translation": <float> [3] -- Coordinate system origin in meters: x, y, z.孙辉法语
吉林省四六级报名
"rotation": <float> [4] -- Coordinate system orientation as quaternion: w, x, y, z.
"camera_intrinsic": <float> [3, 3] -- Intrinsic camera calibration. Empty for nsors that are not cameras.英语代考
}
则此时的translation和rotation就是对应的平移，旋转关系，利⽤⾃带的源码geometry_utils中的transform_matrix，可以得到旋转平移矩阵，采⽤类⾥⾯的transform()⽅法实现对点云从雷达坐标系到IMU坐标系的转换，然后再利⽤ego_po实现从IMU坐标系到世界坐标系的转换.lily思维英语怎么样
