均匀采样
一、算法原理
均匀采样通过构建指定半径的球体对点云进行下采样滤波，将每一个球内距离球体中心最近的点作为下采样之后的点输出。
体素滤波（下采样）是建立一个立方体，均匀采样是建立一个球。
二、代码实现
from pclpy import pcl
def point_cloud_viewer(cloud, cloud_filtered):
# Open 3D viewer and add point cloud and normals
viewer = pcl.visualization.PCLVisualizer("cloud_viewer")
v0 = 1
viewer.createViewPort(0.0, 0.0, 0.5, 1.0, v0)
viewer.setBackgroundColor(0.0, 0.0, 0.0, v0)
single_color = pcl.visualization.PointCloudColorHandlerCustom.PointXYZ(cloud, 0.0, 255.0, 0.0)
viewer.addPointCloud(cloud, single_color, "sample cloud1", v0)
v1 = 2
viewer.createViewPort(0.5, 0.0, 1.0, 1.0, v1)
viewer.setBackgroundColor(0.0, 0.0, 0.0, v1)
single_color = pcl.visualization.PointCloudColorHandlerCustom.PointXYZ(cloud_filtered, 255.0, 0.0, 0.0)
viewer.addPointCloud(cloud_filtered, single_color, "sample cloud2", v1)
viewer.setPointCloudRenderingProperties(0, 1, "sample cloud1", v0)
viewer.setPointCloudRenderingProperties(0, 1, "sample cloud2", v1)
# viewer.addCoordinateSystem(1.0) # 显示坐标轴
while not viewer.wasStopped():
viewer.spinOnce(10)
if __name__ == '__main__':
# 读取点云数据
cloud = pcl.PointCloud.PointXYZ()
cloud_filtered = pcl.PointCloud.PointXYZ()
reader = pcl.io.PCDReader()
reader.read('bunny.pcd', cloud)
print("采样前点的个数为: ", cloud.size())
# 创建均匀采样滤波器
us = pcl.filters.UniformSampling.PointXYZ()
us.setInputCloud(cloud) # 输入点云
us.setRadiusSearch(0.005) # 设置滤波时创建的球体半径
us.filter(cloud_filtered)
print("均匀采样后点的个数为: ", cloud_filtered.size())
# writer = pcl.io.PCDWriter()
# writer.write("rs.pcd", cloud_filtered)
# 可视化结果
point_cloud_viewer(cloud, cloud_filtered)