python读取pcd文件_（一）读取PCD文件

下面是一个简单的读取PCD文件并显示的代码：

#include

void main()

{

/* Create Point Cloud */

pcl::PointCloud<:pointxyzrgba>::Ptr cloud(new pcl::PointCloud<:pointxyzrgba>);

/* Read PCD File */

/* Read Wrong */

if (- == pcl::io::loadPCDFile<:pointxyzrgba>("table_scene_lms400.pcd", *cloud))

{

return;

}

/* Then show the point cloud */

boost::shared_ptr<:visualization::pclvisualizer> viewer(new pcl::visualization::PCLVisualizer("office chair model"));

viewer->setBackgroundColor(, , );

pcl::visualization::PointCloudColorHandlerRGBField<:pointxyzrgba> rgba(cloud); //Maybe set the cloud to he handler rgba?

viewer->addPointCloud<:pointxyzrgba>(cloud, rgba, "sample cloud"); //Add a Point Cloud (templated) to screen. Q:Some questions here

viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, , "sample cloud"); //Set the rendering properties

//viewer->addCoordinateSystem(1.0); //Adds 3D axes describing a coordinate system to screen at 0,0,0

viewer->initCameraParameters (); //Initialize camera parameters with some default values.

/* Show the point cloud */

while (!viewer->wasStopped ())

{

viewer->spinOnce (); //updates the screen loop

boost::this_thread::sleep (boost::posix_time::microseconds ());

}

pcl::io::loadPCDFile用于读取一个PCD文件至一个PointCloud类型，这里就是将table_scene_lms400.pcd文件里的数据读取至cloud里。

在PCL文档里关于pcl::io::loadPCDFile的实现有3个，我目前只看了第一种。

下面看看loadPCDFile在namespace io里的实现：

template inline int

loadPCDFile (const std::string &file_name, pcl::PointCloud &cloud)

{

pcl::PCDReader p;

return (p.read (file_name, cloud));

}

可以看到loadPCDFile 这个内联函数，就是调用了一下pcl::PCDReader里的read函数。

继续看PCDReader函数：

template int

read (const std::string &file_name, pcl::PointCloud &cloud, const int offset = 0)

{

pcl::PCLPointCloud2 blob;

int pcd_version;

int res = read (file_name, blob, cloud.sensor_origin_, cloud.sensor_orientation_, pcd_version, offset);

// If no error, convert the data

if (res == 0)

pcl::fromPCLPointCloud2 (blob, cloud);

return (res);

}

最后在pdc_io.cpp里找到代码:

int

pcl::PCDReader::read (const std::string &file_name, pcl::PCLPointCloud2 &cloud,

Eigen::Vector4f &origin, Eigen::Quaternionf &orientation, int &pcd_version,

const int offset)

{

pcl::console::TicToc tt;

tt.tic ();

int data_type;

unsigned int data_idx;

int res = readHeader (file_name, cloud, origin, orientation, pcd_version, data_type, data_idx, offset);

if (res < )

return (res);

unsigned int idx = ;

// Get the number of points the cloud should have

unsigned int nr_points = cloud.width * cloud.height;

// Setting the is_dense property to true by default

cloud.is_dense = true;

if (file_name == "" || !boost::filesystem::exists (file_name))

{

PCL_ERROR ("[pcl::PCDReader::read] Could not find file '%s'.\n", file_name.c_str ());

return (-);

}

// if ascii

if (data_type == )

{

// Re-open the file (readHeader closes it)

std::ifstream fs;

fs.open (file_name.c_str ());

if (!fs.is_open () || fs.fail ())

{

PCL_ERROR ("[pcl::PCDReader::read] Could not open file %s.\n", file_name.c_str ());

return (-);

}

fs.seekg (data_idx);

std::string line;

std::vector<:string> st;

// Read the rest of the file

try

{

while (idx < nr_points && !fs.eof ())

{

getline (fs, line);

// Ignore empty lines

if (line == "")

continue;

// Tokenize the line

boost::trim (line);

boost::split (st, line, boost::is_any_of ("\t\r "), boost::token_compress_on);

if (idx >= nr_points)

{

PCL_WARN ("[pcl::PCDReader::read] input file %s has more points (%d) than advertised (%d)!\n", file_name.c_str (), idx, nr_points);

break;

}

size_t total = ;

// Copy data

for (unsigned int d = ; d < static_cast (cloud.fields.size ()); ++d)

{

// Ignore invalid padded dimensions that are inherited from binary data

if (cloud.fields[d].name == "_")

{

total += cloud.fields[d].count; // jump over this many elements in the string token

continue;

}

for (unsigned int c = ; c < cloud.fields[d].count; ++c)

{

switch (cloud.fields[d].datatype)

{

case pcl::PCLPointField::INT8:

{