如何理解KITTI相机校准文件？

Question

我正在研究KITTI数据集.
我已经下载了对象数据集(左和右)和对象集的相机校准矩阵.

我想使用立体声信息.
但我不知道如何获得两个相机的内在矩阵和R | T矩阵.我不明白校准文件的含义.

校准文件的内容:

P0: 
7.070493000000e+02 0.000000000000e+00 6.040814000000e+02 0.000000000000e+00 
0.000000000000e+00 7.070493000000e+02 1.805066000000e+02 0.000000000000e+00 
0.000000000000e+00 0.000000000000e+00 1.000000000000e+00 0.000000000000e+00
P1: 
7.070493000000e+02 0.000000000000e+00 6.040814000000e+02 -3.797842000000e+02 
0.000000000000e+00 7.070493000000e+02 1.805066000000e+02 0.000000000000e+00 
0.000000000000e+00 0.000000000000e+00 1.000000000000e+00 0.000000000000e+00
P2: 
7.070493000000e+02 0.000000000000e+00 6.040814000000e+02 4.575831000000e+01 
0.000000000000e+00 7.070493000000e+02 1.805066000000e+02 -3.454157000000e-01 
0.000000000000e+00 0.000000000000e+00 1.000000000000e+00 4.981016000000e-03
P3: 
7.070493000000e+02 0.000000000000e+00 6.040814000000e+02 -3.341081000000e+02 
0.000000000000e+00 7.070493000000e+02 1.805066000000e+02 2.330660000000e+00 
0.000000000000e+00 0.000000000000e+00 1.000000000000e+00 3.201153000000e-03
R0_rect: 
9.999128000000e-01 1.009263000000e-02 -8.511932000000e-03 
-1.012729000000e-02 9.999406000000e-01 -4.037671000000e-03 
8.470675000000e-03 4.123522000000e-03 9.999556000000e-01
Tr_velo_to_cam: 
6.927964000000e-03 -9.999722000000e-01 -2.757829000000e-03 -2.457729000000e-02 
-1.162982000000e-03 2.749836000000e-03 -9.999955000000e-01 -6.127237000000e-02 
9.999753000000e-01 6.931141000000e-03 -1.143899000000e-03 -3.321029000000e-01
Tr_imu_to_velo: 
9.999976000000e-01 7.553071000000e-04 -2.035826000000e-03 -8.086759000000e-01 
-7.854027000000e-04 9.998898000000e-01 -1.482298000000e-02 3.195559000000e-01 
2.024406000000e-03 1.482454000000e-02 9.998881000000e-01 -7.997231000000e-01

Answer 1

从README,

传感器校准zip存档包含文件,以行对齐顺序存储矩阵,这意味着第一个值对应于第一行:

calib_cam_to_cam.txt:相机到相机的校准

• S_xx:整流前图像xx的1x2尺寸
• K_xx:整流前摄像机xx的3x3校准矩阵
• D_xx:整流前摄像机xx的1x5失真矢量
• R_xx:相机xx的3x3旋转矩阵(外部)
• T_xx:相机xx的3x1平移向量(外在的)
• S_rect_xx:整流后图像xx的1x2尺寸
• R_rect_xx:3x3整流旋转以使图像平面共面
• P_rect_xx:整流后的3x4投影矩阵

注意:使用此数据集时,您很可能只需要访问P_rect_xx,因为此矩阵对经过校正的图像序列有效.保持