高通VR 双目IMU标定文件device_calibration

To quote Thomas Jefferson: "He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. That ideas should freely spread from one to another over the globe, for the moral and mutual instruction of man, and improvement of his condition, seems to have been peculiarly and benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density at any point, and like the air in which we breathe, move, and have our physical being, incapable of confinement or exclusive appropriation." Jefferson was one awesome dude.

device_calibration.xml

<?xml version="1.0" encoding="UTF-8" ?>
<DeviceConfiguration deviceUID="not_configured">
    <Camera name="default_cam_0" id="0">
        <Calibration size="640 400 " principal_point="318.04222 196.26305 " focal_length="288.13625 288.13625 " model="FISHEYE_4_PARAMETERS" radial_distortion="-0.014121161 0.013300037 0.0021744101 -0.0032311648 0 0 " />
        <Rig translation="0 0 0 " rowMajorRotationMat="1 0 0 0 1 0 0 0 1 " />
        <TimeAlignment delta="0.001937" />
    </Camera>
    <Camera name="default_cam_1" id="1">
        <Calibration size="640 400 " principal_point="314.02564 196.00008 " focal_length="288.10863 288.10863 " model="FISHEYE_4_PARAMETERS" radial_distortion="-0.012481916 0.012654325 0.00090495103 -0.0024938287 0 0 " />
        <Rig translation="-0.1010911 -0.00085444677 -0.0014054468 " rowMajorRotationMat="0.99893069 -0.015650516 -0.043503914 0.014852501 0.99971658 -0.018606644 0.043782786 0.017940607 0.99887997 " />
        <TimeAlignment delta="0.001937" />
    </Camera>
    <Image format="interleaved" />
    <SFConfig>
        <Stateinit ombc="-2.2159839 2.2214348 0.037660594 " tbc="-0.0012271023 0.017154568 -0.0073502717 " aBias="-0.1589957 -0.36201436 -0.20936155 " wBias="-0.001751474 -0.0021026438 0.0031016318 " ka="-0.013695739 -0.0048905321 -0.014068503 " kg="0.0049880516 0.0071219524 0.0037303694 " na="0.018631337 -0.023253099 -0.00019934779 " ng="-0.00056591565 -3.1185286e-05 -0.0041183801 " ombg="0.0034282422 0.019248956 0.0074587392 " delta="0.001937" />
    </SFConfig>
</DeviceConfiguration>

内容解析

device_calibration.xml中包含双目IMU标定结果

双目相机：

• size ： 图片尺寸
• principal_point ：相机内参 u, v
• focal_length ：相机内参 fx, fy
• model : 畸变模型
• radial_distortion : 相机内参 k1, k2, p1, p2, k3
• TimeAlignment : 相机与IMU的时间偏移 单位s
• rowMajorRotationMat ：相对左相机的旋转矩阵
• translation ：相对左相机的平移矩阵

IMU

• ombc ：IMU相对左相机的旋转向量
• tbc ： IMU相对左相机的平移向量
• aBias ： accel bias
• wBias： gyro bias
• ka：accel scale factor
• kg：gyro scale factor
• na：accel nonorthogonalities
• ng：gyro nonorthogonalities
• ombg：rotation vector from gyroscope to accelerometer
• delta：time shift