// sort blobs
    void SortBlobs()
    {
        struct myclass {
            bool operator() (CBlob* b1,CBlob* b2)
            {
                return (b1->GetArea() < b2->GetArea());
            }
        } blobComp;

        std::sort(m_blobs.begin(),m_blobs.end(),blobComp);
    }

If you want to sort the blobs based on their x coordinates, change the 7th line of above code to

return (b1->GetBoundingBox().x < b2->GetBoundingBox().x);

.

The code reads the points coordinates only. Please see the code for details.

For details of LiDar file format, please visit this link.

#include "mex.h"
//#include <math.h>
#include <iostream>
#include <fstream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* This is a simple code to read LiDar file in matlab. It only reads only point coordinates now.
 * Syntax : points = LASReader('filename.las');
 *     points is a matrix of size 3 x numOfPoints.
 *
 *
 * Please email me at ychi@cise.ufl.edu if you have any questions.
 * Jason Yu-Tseh Chi
 **/

using namespace std;

void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
    if(nrhs != 1)
    {
        mexErrMsgTxt("Error: Syntax: reader(filename);\n");
    }

    //mexPrintf("begin reader\n");
    int sLength;
    // size of file header
    int headerSize = 227;
    mxArray *lData;
    char *fname;
    unsigned char header[227];
    unsigned int nPoints;
    //double xScale, yScale, zScale, xOffset, yOffset, zOffset;
    double scales[3],offsets[3], mins[3], maxs[3];

    int pRecLength, offset2Data;

    // read filename
    // get the length
    sLength = mxGetN(prhs[0])+1;
    fname = new char[sLength];
    // copy the filename
    mxGetString(prhs[0], fname, sLength);
    mexPrintf("The file to be opened is %s\n\n", fname);

    // open the LiDar file
    ifstream ifs(fname, ios::in|ios::binary);
    if(!ifs.good())
    {   mexErrMsgTxt("Error! File open error!");
        return;
    }

    // go to the end of the file to get the fileSize
    ifs.seekg(0, ios::end);
    int fileSize = ifs.tellg();
    ifs.seekg(0, ios::beg);

    // read the file header first;
    ifs.read((char*)header, headerSize);

    // read file signature. It has to be LASF otherwise it's not a valid LAS file.
    char four[5];
    memcpy(four,header,4);
    four[4] = '\0';
    mexPrintf("======= File INFO ======\n");
    mexPrintf("File Signature:\t\t %s (If it's not LASF, this file is not a valid LIDar file.)\n",four);

    // header size
    unsigned short temp;
    memcpy((unsigned char*)&temp,header+94,2);
    mexPrintf("Header Size: \t\t %d\n", (int)temp);

    // Offset to Data. Will use this value later when reading points data.
    unsigned long temp1;
    memcpy((unsigned char*)&temp1, header+94+2, 4);
    offset2Data = (int)temp1;
    mexPrintf("Offset to Data: \t %d\n", (int)offset2Data);

    // FOrmat ID.
    unsigned char t1;
    memcpy(&t1,header+94+2+4+4,1);
    mexPrintf("Point Data Format ID:\t %d\n", (int)t1);

    // Point record length. Will use this value later when reading points data.
    memcpy((unsigned char*)&temp,header+94+2+4+4+1,2);
    pRecLength = (int)temp;
    mexPrintf("Point Record Length: \t %d\n", pRecLength);

    // Number of points. Will use this value later when reading points data.
    memcpy((unsigned char*)&temp1,header+94+2+4+4+2+1,4);
    nPoints = temp1;
    mexPrintf("Number of Points: \t %d\n", (int)nPoints);

    // Scales and offsets.
    double temp2;
    memcpy((unsigned char*)&temp2,header+131,8);
    scales[0] = temp2;
    memcpy((unsigned char*)&temp2,header+131+8,8);
    scales[1] = temp2;
    memcpy((unsigned char*)&temp2,header+131+16,8);
    scales[2] = temp2;
    mexPrintf("Scales: \t\t (%.5f, %.5f, %.5f)\n", scales[0], scales[1], scales[2]);

    memcpy((unsigned char*)&temp2,header+155,8);
    offsets[0] = temp2;
    memcpy((unsigned char*)&temp2,header+155+8,8);
    offsets[1] = temp2;
    memcpy((unsigned char*)&temp2,header+155+16,8);
    offsets[2] = temp2;
    mexPrintf("Offsets: \t\t (%.5f, %.5f, %.5f)\n", offsets[0], offsets[1], offsets[2]);

    // max's and min's in X, Y, and Z direction
    memcpy((unsigned char*)&temp2,header+179,8);
    maxs[0] = temp2;
    memcpy((unsigned char*)&temp2,header+179+8,8);
    mins[0] = temp2;
    memcpy((unsigned char*)&temp2,header+179+16,8);
    maxs[1] = temp2;
    memcpy((unsigned char*)&temp2,header+179+24,8);
    mins[1] = temp2;
    memcpy((unsigned char*)&temp2,header+179+32,8);
    maxs[2] = temp2;
    memcpy((unsigned char*)&temp2,header+179+30,8);
    mins[2] = temp2;

    mexPrintf("MaxXYZ: \t\t (%.5f, %.5f, %.5f)\n", maxs[0], maxs[1], maxs[2]);
    mexPrintf("MinXYZ: \t\t (%.5f, %.5f, %.5f)\n", mins[0], mins[1], mins[2]);

    mexPrintf("==========================================\n");

    // temp for reading one point
    long coor[3];
    // pointer to
    double *x;

    // will return a size of 3 x NumberOfPoints matrix back to matlab.
    plhs[0] = mxCreateDoubleMatrix(3, nPoints,mxREAL);
    x =mxGetPr(plhs[0]);

    // move to the data section of the file.
    ifs.seekg(offset2Data,ios::beg);
    // read point by point
    for(int i=0;i<nPoints;i++)
    {
        ifs.seekg(offset2Data+i*pRecLength,ios::beg);
        ifs.read((char*)coor,12);

        // consider the offsets and scales.
        x[i*3] = (double)coor[0]*scales[0] + offsets[0];
        x[i*3+1] = (double)coor[1]*scales[1] + offsets[1];
        x[i*3+2] = (double)coor[2]*scales[2] + offsets[2];
        //mexPrintf("(%.4f,%.4f,%.4f)\n",x[3*i],x[3*i+1],x[3*i+2]);
    }

    delete [] fname;
    return;
}

Point deBoor(int k,int degree, int i, double x, double* knots, Point *ctrlPoints)
{   // Please see wikipedia page for detail
	// note that the algorithm here kind of traverses in reverse order
	// comapred to that in the wikipedia page
	if( k == 0)
		return ctrlPoints[i];
	else
	{   
		double alpha = (x-knots[i])/(knots[i+degree+1-k]-knots[i]);
		return (deBoor(k-1,degree, i-1, x, knots, ctrlPoints)*(1-alpha )+deBoor(k-1,degree, i, x, knots, ctrlPoints)*alpha );
	}
}

The Point class is defined as the follow:

class Point
{
public:
	Point(){x=0.;y=0.;z=0.;};
	// copy operator
	Point operator=(const Point pt) ;
	Point operator+(const Point pt) const;
	//Point operator-(const Point pt) const;
	Point operator*(double m) const;
	Point operator/(double m) const;
	double x,y,z;
};

Point Point::operator=(const Point pt)
{
	x = pt.x;
	y = pt.y;
	z = pt.z;
	return *this;
}
Point Point::operator+(const Point pt) const
{
	Point temp;
	temp.x = x + pt.x;
	temp.y = y + pt.y;
	temp.z = z + pt.z;
	return temp;
}
Point Point::operator*(double m) const
{
	Point temp;
	temp.x = x*m;
	temp.y = y*m;
	temp.z = z*m;
	return temp;
}
Point Point::operator/(double m) const
{
	Point temp;
	temp.x = x/m;
	temp.y = y/m;
	temp.z = z/m;
	return temp;
}

1. Install texlive-extra-utils which contains epstopdf.

sudo apt-get install texlive-extra-utils

2. Insert the following code in in the preamble of your document.

\newif\ifpdf
\ifx\pdfoutput\undefined
   \pdffalse
\else
   \pdfoutput=1
   \pdftrue
\fi
\ifpdf
   \usepackage{graphicx}
   \usepackage{epstopdf}
   \DeclareGraphicsRule{.eps}{pdf}{.pdf}{`epstopdf #1}
   \pdfcompresslevel=9
\else
   \usepackage{graphicx}
\fi

3. Include eps graphics like usual

\includegraphics[width=7in]{result_1.eps}

4. Compile the tex file with -shell-escape option

 pdflatex -shell-escape texWithEPSYAY.tex

During the compiling pdflatex converts the included eps graphic files into pdf files on the fly using epstopdf. After compiling, esptopdf generates a lot of pdf files (conversion from eps files). You will find the compile (is compile a noun?) a little bit slow. That is because it takes some time for epstopdf to convert eps files to pdf files. As one can imagine, it will become REALLY slow as the number of eps graphics included in a document increases. One way to fix this problem is that when inserting an eps graphic in a document, LEAVE THE FILE EXTENSION OFF. For example, instead of

\includegraphics[width=7in]{result_1.eps}

use

\includegraphics[width=7in]{result_1}.

By this way, pdflatex first checks if result_1.pdf exists. If not, it locates result_1.eps and converts it to a pdf file. When result_1.pdf does exist, it simply inserts result_1.pdf in the document. Therefore, pdflatex only does the conversion when the corresponding pdf file does not exist. If you do NOT leave the file extension off, pdflatex would convert the eps graphics in the document to pdf files every time you compile.

Hope this helps.

epstopdf --exact bad.eps

It will probably generate an warning msg like “Warning: BoundingBox not found!” and the resulting pdf is still wrong. One way to fix this problem is to use epstool

epstool --copy --bbox bad.eps --output good.eps

The –bbox option tells epstool to generate a (correct) bounding box for the eps file. With a correctly defined bounding box, you can easily convert an eps file to a pdf file.

epstopdf --exact good.eps

The results are shown in the 2nd row of the picture below. epstopdf generated an pdf file in the same size as the eps file.

1. Launch itune and select a song you want to convert. The mp3/ACC files must be imported to iTune already.
2. Right click on the song and select Get Info from the pop-up menu.
3. Select Options tab from the Info window as shown in the figure.
   
4. Check Start Time and Stop Time as shown in the figure above. Set the time interval. Make sure it does not exceed 30 seconds.
5. Click OK.
6. Now you are back to iTune main window. Right click on the same song you just selected. Select Create AAC version from the pop-up menu.
7. itune will generate an AAC version of the song you just selected. This AAC format song will appear in itune with the same file name but shorter.
8. Right click the newly generated one and select Copy from the pop-up menu.
9. Paste this file on Desktop (or whatever folder you want).
10. Change the file extension from m4a to m4r (r as in ringtone ).
    
11. Import this .m4r file to iTune. You should be able to see it under Ringtones in iTune. Plug your iPhone in and sync it. You got your free ringtones!!!!

2. Let the Package installer software install it. Restart firefox and it should be working.

If it’s still not working, follow the following steps.

3. Open Terminal and input
$> firefox &
to execute firefox.

4. Go to youtube.com and click on any video. It will be just like step 1 but this time you can see the error message from the Terminal. For me, the error messages say
LoadPlugin: failed to initialize shared library /usr/lib/adobe-flashplugin/libflashplayer.so [libnss3.so: cannot open shared object file: No such file or directory]
The problem is not in flash player but because of a dependency lib of flash player mssing .

5. Open Synaptic package manager (System >> Administration >> Synaptic package manager) and install the missing lib (libnss3). Restart firefox and the flash should work fine.

1. #> sudo apt-get install davfs2

2. create a folder
mkdir /media/webdav

3. Mount remote webdav server by
sudo mount -t davfs https://ip_address:port /media/webdav

%// Will open an avi file name test.avi in local folder
aviobj = avifile('test.avi');
%// the quality of this video file
aviobj.Quality = 80;
%// compression method. See matlab manual for details.
aviobj.COMPRESSION ='None';%%color image

for i =1:numOfFrames
    %// apply image processing algorithms to the image here. 
    %// image must be in size width x height x 3
    %//  in other words, color image. 
    ..........
    ..........
    %// add image to the end of the avi file
    aviobj = addframe(aviobj,image);
end
%// close the file handle.
aviobj = close(aviobj);

Click here for detail instruction on addframe function.

Keywords: convert images jpb bmp to video avi compressed codec