Kitti_Visualize

Dependencies

Common dependencies like numpy, matplotlib, PIL

Project structure

File	Description
kitti_demo_notebook.ipynb	Jupyter Notebook with dataset visualisation routines and output.
Kitti.py	Methods for parsing labels, calibration information, image and lidar point clouds.
utils.py	Method for projecting 3D to 2D and its invers transformation.

Dataset

Download the data (calib, image_2, label_2, Velodyne) from KITTI website.

And place it in your data folder at Kitti. The folder structure is as following:

kitti
    training
        calib
            000000.txt
        image_2
            000000.png
        label_2
            000000.txt
        velodyne
            000000.bin
        pred
            000000.txt

Demo

For a implementation demo see notebook. For more exploration and implementation details see Kittp.py and utils.py.

1. 3D boxes on LiDar point cloud in velodyne coordinate. Implemented by draw_3DBBox_in_velo(). RESULT.
2. 2D and 3D boxes on in image2 coordinate. Implemented by draw_2DBBox_in_rgb() and draw_3DBBox_in_rgb(). 2D_RESULT and 3D_RESULT.
3. Point clouds visualize in velodyne coordinate. Implemented by draw_pointclouds_in_velo(). RESULT.
4. LiDar data on Camera image. Implmented by draw_pointclouds_in_rgb(). RESULT.

Part of results:

NOTICE:

1. 3d XYZ in <label>.txt are in rect camera coord.
2. 2d box xy are in image2 coord
3. Points in <lidar>.bin are in Velodyne coord.

Coordinate Transformation:

 y_image2 = P^2_rect * x_rect
 y_image2 = P^2_rect * R0_rect * Tr_velo_to_cam * x_velo
 x_ref = Tr_velo_to_cam * x_velo
 x_rect = R0_rect * x_ref

 P^2_rect = [f^2_u,  0,      c^2_u,  -f^2_u b^2_x;
             0,      f^2_v,  c^2_v,  -f^2_v b^2_y;
             0,      0,      1,      0]
             = K * [1|t]

Coordinate Visualization:

    image2 coord:
        ----> x-axis (u)
    |
    |
    v y-axis (v)

    Velodyne coordinate system:
    front x, left y, up z

    #     7 -------- 4
    #    /|  (z)    /|
    #   6 ---|---- 5 .
    #   | |  |     | |
    #   . 3 -|------ 0
    #   |/   .- - -|/ - - -> (y)
    #   2 --/------- 1
    #      /
    #     /
    #   (x)

    rect/ref camera coord:
    right x, down y, front z

    #     7 -------- 4
    #    /|         /|
    #   6 -------- 5 .
    #   | |        | |
    #   . 3 -------- 0
    #   |/   .- - -|/ - - -> (x)
    #   2 --/-|----- 1
    #      /  |
    #     /   | (y)
    #    (z)

    Ref (KITTI paper): http://www.cvlibs.net/publications/Geiger2013IJRR.pdf

More details about KITTI, Here!