知微传感Dkam系列3D相机SDK例程篇：CSharp点云滤波

3D相机点云滤波

写在前面

• 本人从事机器视觉细分的3D相机行业。编写此系列文章主要目的有：
  • 1、便利他人应用3D相机，本系列文章包含公司所出售相机的SDK的使用例程及详细注释；
  • 2、促进行业发展及交流。
• 知微传感Dkam系列3D相机可以应用于定位分拣、焊接焊缝提取、逆向建模、检测测量等领域

点云滤波及API说明

点云滤波说明

• 知微传感为其3D相机输出的点云准备了滤波API，用于噪声或离群点的滤除
• 点云滤波功能在上位机完成
• 被滤除的点位置保留，指标值为0
• 滤波API在获取点云后使用

相关API

• FilterPointCloudCSharp 点云滤波
  • void FilterPointCloudCSharp(Camera_Object_C* camera_obj,PhotoInfoCSharp &raw_data_info, char *xyz, int pixel_size, double level)
  • 函数功能: 滤波
  • 参 数: camera_obj：相机的结构体指针；raw_data_info：采集的点云数据；xyz：像素点；pixel_size：像素大小；level：滤波的等级 （取值范围大于 0//等于 0 所有的点云都被过滤//趋于 0 滤波效果越明显）
  • 返回值: 无
  • 原理：统计滤波
• SpatialFilterPointcloudCSharp 空间滤波
  • int SpatialFilterPointcloudCSharp(Camera_Object_C* camera_obj, PhotoInfoCSharp &raw_data_info, char *xyz, int pixel_size, int Area_PointCloudCount)
  • 函数功能：空间滤波
  • 参数：camera_obj：相机的结构体指针；raw_data：获取的点云数据；xyz：像素点；pixel_size：像素大小；Area_PointCloudCount：滤波范围 (取值范围大于0//等于0滤波不起作用//取值越大于0效果越明显，取值范围：0~99)
  • 返回值：0，成功；非0，失败
  • 原理：将输入的点云分成30×30×30个空间，空间内有效点的数量少于给定值时，将该空间内多有点滤除（实际将点的坐标值赋值为0），处理后的点仍存放在raw_data中

例程及注释

• 本例程基于WIN10+VisualStudio2022+DkamSDK_1.6.83
• DkamSDK的配置方法请参考SDK说明书
• 本例程在D330XS型相机上验证

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace filter
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello ZhiSENSOR!");

            //**********************************************查询、连接相机****************************************************

            int camer_num = 0;
            int camera_ret = -1;

            //想要连接的相机IP
            String tarCameraIP = "192.168.40.91";

            //发现局域网内的相机
            camer_num = DkamSDK_CSharp.DiscoverCamera();
            Console.WriteLine("局域网内共有" + camer_num + "台3D相机");
            //显示局域网内相机IP
            for (int i = 0; i < camer_num; i++)
            {
                Console.WriteLine("局域网内相机的IP为：" + DkamSDK_CSharp.CameraIP(i));

                if (String.Compare(DkamSDK_CSharp.CameraIP(i), tarCameraIP) == 0)
                {
                    camera_ret = i;
                }
            }

            Console.WriteLine("连接IP为：" + tarCameraIP + "的相机");

            //连接相机
            SWIGTYPE_p_CAMERA_OBJECT camera = DkamSDK_CSharp.CreateCamera(camera_ret);
            int connect = DkamSDK_CSharp.CameraConnect(camera);
            

            if (connect == 0)
            {
                Console.WriteLine("相机连接成功！");
                //获取当前红外相机的宽和高
                SWIGTYPE_p_int width_gray = DkamSDK_CSharp.new_intArray(0);
                DkamSDK_CSharp.GetCameraWidth(camera, width_gray, 0);
                int width = DkamSDK_CSharp.intArray_getitem(width_gray, 0);

                SWIGTYPE_p_int height_gray = DkamSDK_CSharp.new_intArray(0);
                DkamSDK_CSharp.GetCameraHeight(camera, height_gray, 0);
                int height = DkamSDK_CSharp.intArray_getitem(height_gray, 0);

                Console.WriteLine("红外图宽度：" + width + "    红外图高度：" + height);

                //**********************************************采集点云数据****************************************************
                //定义点云大小
                PhotoInfoCSharp PointCloud_data = new PhotoInfoCSharp();
                int pointsize = width * height * 6;
                byte[] point_pixel = new byte[pointsize];

                //开启数据流通道(0:红外 1:点云 2:RGB)
                //点云
                int streampoint = DkamSDK_CSharp.StreamOn(camera, 1);
                if (streampoint == 0)
                {
                    Console.WriteLine("点云通道打开成功！");
                }
                else
                {
                    Console.WriteLine("点云通道打开失败！！！     错误码：" + streampoint);
                }

                //开始接受数据
                int start = DkamSDK_CSharp.AcquisitionStart(camera);
                if (start == 0)
                {
                    Console.WriteLine("可以开始接收数据！");
                }
                else
                {
                    Console.WriteLine("不能接收数据！！！     错误码：" + start);
                }

                //刷新缓冲区
         
                DkamSDK_CSharp.FlushBuffer(camera, 1);


                Console.WriteLine("等待数据采集、传输。。。");

                //获取点云数据
                int capturepoint = DkamSDK_CSharp.TimeoutCaptureCSharp(camera, 1, PointCloud_data, point_pixel, pointsize, 10000000);
                if (capturepoint == 0)
                {
                    Console.WriteLine("点云数据接收成功！");
                }
                else
                {
                    Console.WriteLine("点云数据接收失败！！！     错误码：" + capturepoint);
                }


                Console.WriteLine();

                //保存点云数据
                int savepoint = DkamSDK_CSharp.SavePointCloudToPcdCSharp(camera, PointCloud_data, point_pixel, pointsize, "pointcloud.pcd");
                if (savepoint == 0)
                {
                    Console.WriteLine("原始点云数据保存成功！");
                }
                else
                {
                    Console.WriteLine("原始点云数据保存失败！！！     错误码：" + savepoint);
                }


                //*********************************************滤波****************************************************

                //滤波
                DkamSDK_CSharp.FilterPointCloudCSharp(camera, PointCloud_data, point_pixel, pointsize, 1);
                //保存滤波后点云数据
                savepoint = DkamSDK_CSharp.SavePointCloudToPcdCSharp(camera, PointCloud_data, point_pixel, pointsize, "pointcloud_Filter.pcd");
                if (savepoint == 0)
                {
                    Console.WriteLine("滤波点云数据保存成功！");
                }
                else
                {
                    Console.WriteLine("滤波点云数据保存失败！！！     错误码：" + savepoint);
                }


                //*********************************************空间滤波****************************************************

                //空间滤波
                int spfilter = DkamSDK_CSharp.SpatialFilterPointcloudCSharp(camera, PointCloud_data, point_pixel, pointsize, 80);
                if (spfilter == 0)
                {
                    Console.WriteLine("空间滤波成功！");
                }
                else {
                    Console.WriteLine("空间滤波失败！！！     错误码：" + savepoint);
                }
                    //保存滤波后点云数据
                    savepoint = DkamSDK_CSharp.SavePointCloudToPcdCSharp(camera, PointCloud_data, point_pixel, pointsize, "pointcloud_SpatialFilter.pcd");
                if (savepoint == 0)
                {
                    Console.WriteLine("空间滤波点云数据保存成功！");
                }
                else
                {
                    Console.WriteLine("空间滤波点云数据保存失败！！！     错误码：" + savepoint);
                }

           

                //断开相机连接
                int disconnect = DkamSDK_CSharp.CameraDisconnect(camera);
                if (disconnect == 0)
                {
                    Console.WriteLine("成功断开相机！");
                }
                else
                {
                    Console.WriteLine("断开相机失败！！！     错误码：" + disconnect);
                }
                //销毁相机参数
                DkamSDK_CSharp.DestroyCamera(camera);

            }//connect = 0
            else
            {
                Console.WriteLine("相机连接失败，失败代码：" + connect);
            }

        }//MAIN
    }//PROGRAM
}//NAMESPACE

运行结果

结果对比

• 滤波前
  

• 滤波后
  

• 滤波+空间滤波后
  

• 对比可知，滤波功能可以有效滤除噪点或离群点

后记

• 知微传感Dkam系列3D相机可以应用于定位分拣、焊接引导、逆向建模、检测测量等领域