kitti timestamps

[dongfangzhou1108]

great appreciate with opening your great work！
first, can you provide dataset passcord to me， no one relpy in mail，
second， And when I see kitti website, the raw point cloud data do not have time information except scan begin and end time,
How do you get the time information?

thanks a lot
best wishes！

[jedeschaud]

Hello,
The password for the dataset folder is : npm3d
CT-ICP does not need the real timestamp of points but only the relative timestamp inside one scan.
For KITTI dataset, we compute the timestamp from the azimuth of points in a scan.
Here the Python line to compute the timestamp :
data[:,3] = float(i-FIRST_INDEX_FRAME)/10.0 + (-np.arctan2(data[:,1], data[:,0])/np.pi+1.0)*0.05

Best Regards

[dongfangzhou1108]

Thank you very much！

[dongfangzhou1108]

sorry，Can you provide the python code for me？thanks a lot！

[jedeschaud]

PLY_Scans_from_KITTI_raw_data.zip

[dongfangzhou1108]

thanks for your code,
but when i check the code, data[:,3] = float(i-FIRST_INDEX_FRAME)/10.0 + (-np.arctan2(data[:,1], data[:,0])/np.pi+1.0)*0.05,
by experiment, i find the beginning of the scan is from back of the lidar,
can you explain it to me? thanks a lot,

here is my experiment, this is a scan ,and the height(z) is the output of float(i-FIRST_INDEX_FRAME)/10.0 + (-np.arctan2(data[:,1], data[:,0])/np.pi+1.0)*5, (ten times of orgin, for viewing), by matlab

[dongfangzhou1108]

i have seen in ct_icp code, you use the max and min of time to compute, but i guess there have a problem?

thank u very much

[pdell-kitware]

thanks for your code, but when i check the code, data[:,3] = float(i-FIRST_INDEX_FRAME)/10.0 + (-np.arctan2(data[:,1], data[:,0])/np.pi+1.0)*0.05, by experiment, i find the beginning of the scan is from back of the lidar, can you explain it to me? thanks a lot,

here is my experiment, this is a scan ,and the height(z) is the output of float(i-FIRST_INDEX_FRAME)/10.0 + (-np.arctan2(data[:,1], data[:,0])/np.pi+1.0)*5, (ten times of orgin, for viewing), by matlab

Hi,

This is not a problem, KITTI's Lidar frames start behind the car, and turn clockwise (when considering the direction of motion),