ORBSLAM3 运行流程 TrackRGBD()函数

这个函数也是在rgbd_tum.cc里被调用的。

 // Pass the image to the SLAM system
        SLAM.TrackRGBD(imRGB,imD,tframe);

Sophus::SE3f System::TrackRGBD(const cv::Mat &im, const cv::Mat &depthmap, const double ×tamp, const vector& vImuMeas, string filename)
{
    if(mSensor!=RGBD  && mSensor!=IMU_RGBD)
    {
        cerr << "ERROR: you called TrackRGBD but input sensor was not set to RGBD." << endl;
        exit(-1);
    }

    cv::Mat imToFeed = im.clone();
    cv::Mat imDepthToFeed = depthmap.clone();
    if(settings_ && settings_->needToResize()){
        cv::Mat resizedIm;
        cv::resize(im,resizedIm,settings_->newImSize());
        imToFeed = resizedIm;

        cv::resize(depthmap,imDepthToFeed,settings_->newImSize());
    }

    // Check mode change
    {
        unique_lock lock(mMutexMode);
        if(mbActivateLocalizationMode)
        {
            mpLocalMapper->RequestStop();

            // Wait until Local Mapping has effectively stopped
            while(!mpLocalMapper->isStopped())
            {
                usleep(1000);
            }

            mpTracker->InformOnlyTracking(true);
            mbActivateLocalizationMode = false;
        }
        if(mbDeactivateLocalizationMode)
        {
            mpTracker->InformOnlyTracking(false);
            mpLocalMapper->Release();
            mbDeactivateLocalizationMode = false;
        }
    }

    // Check reset
    {
        unique_lock lock(mMutexReset);
        if(mbReset)
        {
            mpTracker->Reset();
            mbReset = false;
            mbResetActiveMap = false;
        }
        else if(mbResetActiveMap)
        {
            mpTracker->ResetActiveMap();
            mbResetActiveMap = false;
        }
    }

    if (mSensor == System::IMU_RGBD)
        for(size_t i_imu = 0; i_imu < vImuMeas.size(); i_imu++)
            mpTracker->GrabImuData(vImuMeas[i_imu]);

    Sophus::SE3f Tcw = mpTracker->GrabImageRGBD(imToFeed,imDepthToFeed,timestamp,filename);

    unique_lock lock2(mMutexState);
    mTrackingState = mpTracker->mState;
    mTrackedMapPoints = mpTracker->mCurrentFrame.mvpMapPoints;
    mTrackedKeyPointsUn = mpTracker->mCurrentFrame.mvKeysUn;
    return Tcw;
}

这里起到主要作用的是调用GrabImageRGBD();函数

Sophus::SE3f Tcw = mpTracker->GrabImageRGBD(imToFeed,imDepthToFeed,timestamp,filename);

Sophus::SE3f Tracking::GrabImageRGBD(const cv::Mat &imRGB,const cv::Mat &imD, const double ×tamp, string filename)
{
    mImGray = imRGB;
    cv::Mat imDepth = imD;

    // step 1：将RGB或RGBA图像转为灰度图像
    if(mImGray.channels()==3)
    {
        if(mbRGB)
            cvtColor(mImGray,mImGray,cv::COLOR_RGB2GRAY);
        else
            cvtColor(mImGray,mImGray,cv::COLOR_BGR2GRAY);
    }
    else if(mImGray.channels()==4)
    {
        if(mbRGB)
            cvtColor(mImGray,mImGray,cv::COLOR_RGBA2GRAY);
        else
            cvtColor(mImGray,mImGray,cv::COLOR_BGRA2GRAY);
    }

    // Step 2 ：将深度相机的disparity转为Depth , 也就是转换成为真正尺度下的深度
    if((fabs(mDepthMapFactor-1.0f)>1e-5) && imDepth.type()!=CV_32F)
        imDepth.convertTo(imDepth,CV_32F,mDepthMapFactor);

    // Step 3：构造Frame
    if (mSensor == System::RGBD)
        mCurrentFrame = Frame(mImGray,imDepth,timestamp,mpORBextractorLeft,mpORBVocabulary,mK,mDistCoef,mbf,mThDepth,mpCamera);
    else if(mSensor == System::IMU_RGBD)
        mCurrentFrame = Frame(mImGray,imDepth,timestamp,mpORBextractorLeft,mpORBVocabulary,mK,mDistCoef,mbf,mThDepth,mpCamera,&mLastFrame,*mpImuCalib);

    mCurrentFrame.mNameFile = filename;
    mCurrentFrame.mnDataset = mnNumDataset;

#ifdef REGISTER_TIMES
    vdORBExtract_ms.push_back(mCurrentFrame.mTimeORB_Ext);
#endif
    // Step 4：跟踪
    Track();

    // 返回当前帧的位姿
    return mCurrentFrame.GetPose();

}

这里的关键是

Track();