This is a readme file to explain the data set and a simple viewer.

The algorimth details in generating such a data set can be found in

Zhao, H. Chiba, M., Shibasaki, R., Shao, X., Cui, J., Zha, H., A laser scanner based approach towards driving safety and traffic data collection, IEEE Trans. Intelligent Transportation System, vol.10, no.3, 534-546, 2009.

If you use the data or viewer, you are obligated to cite our research in your report.

For any question, please contact: zhaohj@cis.pku.edu.cn


[Data Sets]

The data set is generated on a run around the Science Buildings of PKU.

It contains the following data files.

a. FILENAME.master and FILENAME.raw 

are pairwised files. FILENAME.raw is a bitmap file in RAW format, FILENAME.master records its master info as follows,

  width		1616		//width of the bitmap
  length	1576		//height of the bitmap
  ox		-161.851138	//the origin's coord. in world coord. syst.
  oy		-223.076419	//corres. to the bitmap pixel (0,0), UNIT:(m,m)
  pixelsize	0.200000	//the bitmap pixel size, UNIT:(m)

For any pixel (i,j), it coord. in world coord. syst. is calculated as follows,

	wx = ox + i*pixelsize
	wy = oy + j*pixelsize

Pixel value of the bitmap is the count of hits by laser scan to the corresponding grid.

There are two bitmap data sets, 

"1st-cleared" is a bitmap after cleaning the noise points on road,
"1st-bline" is a bitmap with boundary lines filling gaps. The boundary points are with a special value of 254.

The procedure for bitmap modification can be found at the end of the document. 

b. FILENAME.nav 

records the sequence of vehicle pos.

time  ang.x  ang.y  ang.z  shv.x  shv.y  shv.z  mat.score
53301207  0  0  -0.104755  0.064000  0.032000  0  0.659280

time is in millisec, angles are in radian, shift parameters are in meter, the last item is the score of matching, [0,1], higher is more reliable.

c. FILENAME.traj 

records the moving objects trajectories that have been detected and tracked along the run.

milli,fno,p.x,p.y,axnum,len0,len1,gp.x,gp.y,gv1.x,gv1.y,gv2.x,gv2.y,ptnum,ist,ied
tno=1
53310703,97,5.927,28.651,0,0.427,0.097,2.807,29.155,0.963,-0.271,0.271,0.963,3,168,-858993460
//something wrong with the last two items, maybe do not need in your processing

A trajectory is started from
tno=N
followed by the state sequence at each time instance.

At each time instance,
milli is time in millisec, fno might not be necessary in your processing;
the (p.x,p.y) is the location of the moving object in world coordinate system at the time instance; 
the axnum is the major axes number detected from the data appearance, len0 and len1 are the length along each major axis;
gp.x,gp.y,gv1.x,gv1.y,gv2.x,gv2.y are the location, the directional vectors of axis 1, axis 2 in sensor's local coordinate system;
ptnum is the number of laser points on the moving object.

d. FILENAME.mdl, FILENAME.dsx 

are pairwised, where fm.calib, recording the sensor's location and orientation w.r.t the vehicle frame is also used.

You need to correspond the DIR setting in FILENAME.mdl according to your data.
For example, if you put your data in c:\test\1\, you need to change the setting to 
	DIR	c:\test\1\
	DSX	1st-map.dsx

so that DIRDSX can locate your data.

FILENAME.dsx is a binary data file in the following format.

*.dsx contains a header and a sequence of dsrec.

typedef struct {
	float	AngRng;
	float	AngRes;
	float	unit
} header;

typedef struct {
	point3d	ang;			//vehicle orientation
	point3d	shv;			//vehicle position
	long	millisec;		//time of the measurement
	short	rngval[SCANDATASIZE];	//range values
	short	lab[SCANDATASIZE];	//label of the corresponding range val.
} dsrec;

while,
SCANDATASIZE = AngRng/AngRes + 1

e.g. 180/0.5+1 = 361
     100/0.25+1 = 401

A range value in "short" can be converted to a distance in meter by rngval/unit

typedef struct {
	double	x,y,z;
} point3d;



[Usage of MapShow.exe]

1. Start MapShow.exe

2. File->Load Map, select the *.master file, then both the *.master and *.raw withe same filename will be loaded.
   You can use the HOME and END keys to Zoom in and Zoom out the bitmap.

3. You can selectively conduct some of the following steps.

a. File->Load Nav, load *.nav file.

b. File->Load Mv. Obj., load *.traj file.

c. File->Load Scan, select the *.mdl file, then the corresponding *.dsx will be loaded, and extended to laser points.
   Option->Animation, animate the scan data.

4. You can modify the bitmap by follows

a. Select either of the actions
   Action->ClearBgp
   Action->AddBgp
   Action->AddBline

b. Select a rect or line by press the left button of mouse, drag, release

c. If ClearBgp is selected, pixels in the rect will be removed, i.e. values are set to 0;
   If AddBgp is selected, pixels in the rect will be set to 100;
   If AddBline is selected, a special line is drawn with value 254;

d. Save the modified bitmap to *.raw by 
   Action->OutputBgp