opencv matlab三维点云,使用opencv以及pcl将2D图像转换为3D点云

注：本文是在学习了高翔博士的相关博客(http://www.cnblogs.com/gaoxiang12/p/4652478.html)后写成的，纯粹作为一个学习笔记

1.在上一节即http://blog.csdn.net/zhuquan945/article/details/52788278中讲到的 代码根目录/src/ 文件夹中，即在/slam/src中新建一个名字为generatePointCloud.cpp的文件：

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~$ cd ~/slam

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam$ cd src

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam/src$ touch generatePointCloud.cpp

并在generatePointCloud.cpp中写入如下内容：

// C++ 标准库

#include #include using namespace std;

// OpenCV 库

#include #include // PCL 库

#include #include // 定义点云类型

typedef pcl::PointXYZRGBA PointT;

typedef pcl::PointCloudPointCloud;

// 相机内参

const double camera_factor = 1000;

const double camera_cx = 325.5;

const double camera_cy = 253.5;

const double camera_fx = 518.0;

const double camera_fy = 519.0;

// 主函数

int main( int argc, char** argv )

{

// 读取./data/rgb.png和./data/depth.png，并转化为点云

// 图像矩阵

cv::Mat rgb, depth;

// 使用cv::imread()来读取图像

// API: http://docs.opencv.org/modules/highgui/doc/reading_and_writing_images_and_video.html?highlight=imread#cv2.imread

rgb = cv::imread( "./data/162025180951762.png" );

// rgb 图像是8UC3的彩色图像

// depth 是16UC1的单通道图像，注意flags设置-1,表示读取原始数据不做任何修改

depth = cv::imread( "./data/162025372828732.png", -1 );

// 点云变量

// 使用智能指针，创建一个空点云。这种指针用完会自动释放。

PointCloud::Ptr cloud ( new PointCloud );

// 遍历深度图

for (int m = 0; m < depth.rows; m++)

for (int n=0; n < depth.cols; n++)

{

// 获取深度图中(m,n)处的值

ushort d = depth.ptr(m)[n];

// d 可能没有值，若如此，跳过此点

if (d == 0)

continue;

// d 存在值，则向点云增加一个点

PointT p;

// 计算这个点的空间坐标

p.z = double(d) / camera_factor;

p.x = (n - camera_cx) * p.z / camera_fx;

p.y = (m - camera_cy) * p.z / camera_fy;

// 从rgb图像中获取它的颜色

// rgb是三通道的BGR格式图，所以按下面的顺序获取颜色

p.b = rgb.ptr(m)[n*3];

p.g = rgb.ptr(m)[n*3+1];

p.r = rgb.ptr(m)[n*3+2];

// 把p加入到点云中

cloud->points.push_back( p );

}

// 设置并保存点云

cloud->height = 1;

cloud->width = cloud->points.size();

coutis_dense = false;

pcl::io::savePCDFile( "./data/pointcloud.pcd", *cloud );

// 清除数据并退出

cloud->points.clear();

cout< return 0;

}

程序运行时需要数据，故将162025180951762.png

以及

162025372828732.png

存放在源代码根目录下即存放在/slam/data中(如果没有的新建一个)。

然后将/slam/src/中的main.cpp删除

2.为了告诉编译器我们需要编译这个程序，故需要在/slam/src/中建立一个名字为CMakeLists.txt文件，并在CMakeLists.txt中写入如下内容：

# 增加PCL库的依赖

FIND_PACKAGE( PCL REQUIRED COMPONENTS common io )

# 增加opencv的依赖

FIND_PACKAGE( OpenCV REQUIRED )

# 添加头文件和库文件

ADD_DEFINITIONS( ${PCL_DEFINITIONS} )

INCLUDE_DIRECTORIES( ${PCL_INCLUDE_DIRS} )

LINK_LIBRARIES( ${PCL_LIBRARY_DIRS} )

ADD_EXECUTABLE( generate_pointcloud generatePointCloud.cpp )

TARGET_LINK_LIBRARIES( generate_pointcloud ${OpenCV_LIBS}

${PCL_LIBRARIES} )

3.编译新的工程

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam$ mkdir build

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam$ cd build

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam/build$ cmake ..

结果如下：

-- The C compiler identification is GNU 5.4.0

-- The CXX compiler identification is GNU 5.4.0

-- Check for working C compiler: /usr/bin/cc

-- Check for working C compiler: /usr/bin/cc -- works

-- Detecting C compiler ABI info

-- Detecting C compiler ABI info - done

-- Detecting C compile features

-- Detecting C compile features - done

-- Check for working CXX compiler: /usr/bin/c++

-- Check for working CXX compiler: /usr/bin/c++ -- works

-- Detecting CXX compiler ABI info

-- Detecting CXX compiler ABI info - done

-- Detecting CXX compile features

-- Detecting CXX compile features - done

-- Checking for module 'eigen3'

--   Found eigen3, version 3.2.92

-- Found eigen: /usr/include/eigen3

-- Looking for pthread.h

-- Looking for pthread.h - found

-- Looking for pthread_create

-- Looking for pthread_create - not found

-- Looking for pthread_create in pthreads

-- Looking for pthread_create in pthreads - not found

-- Looking for pthread_create in pthread

-- Looking for pthread_create in pthread - found

-- Found Threads: TRUE

-- Boost version: 1.58.0

-- Found the following Boost libraries:

--   system

--   filesystem

--   thread

--   date_time

--   iostreams

--   serialization

--   chrono

--   atomic

--   regex

-- Checking for module 'libopenni'

--   No package 'libopenni' found

-- Could NOT find openni (missing:  OPENNI_LIBRARY OPENNI_INCLUDE_DIRS)

** WARNING ** io features related to openni will be disabled

-- Checking for module 'libopenni2'

--   No package 'libopenni2' found

-- Could NOT find OpenNI2 (missing:  OPENNI2_LIBRARY OPENNI2_INCLUDE_DIRS)

** WARNING ** io features related to openni2 will be disabled

-- Could NOT find ensenso (missing:  ENSENSO_LIBRARY ENSENSO_INCLUDE_DIR)

** WARNING ** io features related to ensenso will be disabled

-- Could NOT find DAVIDSDK (missing:  DAVIDSDK_LIBRARY DAVIDSDK_INCLUDE_DIR)

** WARNING ** io features related to davidSDK will be disabled

-- Could NOT find DSSDK (missing:  _DSSDK_LIBRARIES)

** WARNING ** io features related to dssdk will be disabled

** WARNING ** io features related to pcap will be disabled

** WARNING ** io features related to png will be disabled

-- Found libusb-1.0: /usr/include

** WARNING ** io features related to libusb-1.0 will be disabled

-- looking for PCL_COMMON

-- Found PCL_COMMON: /usr/local/lib/libpcl_common.so

-- looking for PCL_OCTREE

-- Found PCL_OCTREE: /usr/local/lib/libpcl_octree.so

-- looking for PCL_IO

-- Found PCL_IO: /usr/local/lib/libpcl_io.so

-- Found PCL: /usr/lib/x86_64-linux-gnu/libboost_system.so;/usr/lib/x86_64-linux-gnu/libboost_filesystem.so;/usr/lib/x86_64-linux-gnu/libboost_thread.so;/usr/lib/x86_64-linux-gnu/libboost_date_time.so;/usr/lib/x86_64-linux-gnu/libboost_iostreams.so;/usr/lib/x86_64-linux-gnu/libboost_serialization.so;/usr/lib/x86_64-linux-gnu/libboost_chrono.so;/usr/lib/x86_64-linux-gnu/libboost_atomic.so;/usr/lib/x86_64-linux-gnu/libboost_regex.so;/usr/lib/x86_64-linux-gnu/libpthread.so;optimized;/usr/local/lib/libpcl_common.so;debug;/usr/local/lib/libpcl_common.so;optimized;/usr/local/lib/libpcl_octree.so;debug;/usr/local/lib/libpcl_octree.so;vtkCommon;vtkFiltering;vtkImaging;vtkGraphics;vtkGenericFiltering;vtkIO;vtkRendering;vtkVolumeRendering;vtkHybrid;vtkWidgets;vtkParallel;vtkInfovis;vtkGeovis;vtkViews;vtkCharts;optimized;/usr/local/lib/libpcl_io.so;debug;/usr/local/lib/libpcl_io.so;/usr/lib/x86_64-linux-gnu/libboost_system.so;/usr/lib/x86_64-linux-gnu/libboost_filesystem.so;/usr/lib/x86_64-linux-gnu/libboost_thread.so;/usr/lib/x86_64-linux-gnu/libboost_date_time.so;/usr/lib/x86_64-linux-gnu/libboost_iostreams.so;/usr/lib/x86_64-linux-gnu/libboost_serialization.so;/usr/lib/x86_64-linux-gnu/libboost_chrono.so;/usr/lib/x86_64-linux-gnu/libboost_atomic.so;/usr/lib/x86_64-linux-gnu/libboost_regex.so;/usr/lib/x86_64-linux-gnu/libpthread.so;vtkCommon;vtkFiltering;vtkImaging;vtkGraphics;vtkGenericFiltering;vtkIO;vtkRendering;vtkVolumeRendering;vtkHybrid;vtkWidgets;vtkParallel;vtkInfovis;vtkGeovis;vtkViews;vtkCharts

-- Configuring done

WARNING: Target "generate_pointcloud" requests linking to directory "/usr/local/lib".  Targets may link only to libraries.  CMake is dropping the item.

-- Generating done

-- Build files have been written to: /home/zhuquan/slam/build

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam/build$ make

Scanning dependencies of target generate_pointcloud

[ 50%] Building CXX object src/CMakeFiles/generate_pointcloud.dir/generatePointCloud.cpp.o

[100%] Linking CXX executable ../../bin/generate_pointcloud

[100%] Built target generate_pointcloud

如果编译通过的话，就会在/slam/bin/中生成一个名为generate_pointcloud的可执行的二进制文件。

这时候可以执行这个程序：

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam/build$ cd ..

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam$ bin/generate_pointcloud

在终端显示结果如下：

point cloud size = 204186

Point cloud saved.

此时就可以在/slam/data/中生成一个名字为pointcloud.pcd的点云文件了。

此时如果安装了pcl，就可以通过

zhuquan@zhuquan-HP-Z230-Tower-Workstation:~/slam$ pcl_viewer data/pointcloud.pcd

查看生成的点云文件是个什么样子了。

终端结果显示为：

The viewer window provides interactive commands; for help, press 'h' or 'H' from within the window.

> Loading data/pointcloud.pcd [done, 1235 ms :204186 points]

Available dimensions: x y z rgba

在屏幕上就会弹出一个PCD viewer: