KITTI数据中pose含义

Folder ‘poses’:
The folder ‘poses’ contains the ground truth poses (trajectory) for the first 11 sequences. This information can be used for training/tuning your method. Each file xx.txt contains a N x 12 table, where N is the number of frames of this sequence. Row i represents the i’th pose of the left camera coordinate system (i.e., z pointing forwards) via a 3x4 transformation matrix. The matrices are stored in row aligned order (the first entries correspond to the first row), and take a point in the i’th coordinate system and project it into the first (=0th) coordinate system. Hence, the translational part (3x1 vector of column 4) corresponds to the pose of the left camera coordinate system in the i’th frame with respect to the first (=0th) frame. Your submission results must be provided using the same data format.

每个文件xx.txt都包含一个N x 12的内容，其中N是该序列的帧数。第i行通过3x4变换矩阵表示在左相机坐标系中的第i个姿势（即z指向前方）。矩阵按行对齐顺序存储（第一个条目对应于第一行），并在第i个坐标系中取一点并将其投影到第一个（=第0个）坐标系中。因此，平移部分（列4的3x1矢量）对应于左相机坐标系在第i帧中相对于第一（＝第0）帧的姿态。