c++opencvcomputer-visiongeometrypoint-cloud-library

XYZRGB point cloud from ToF camera and RGB camera


Im trying to create a pointcloud from depth data from my ToF camera and overlaying my RGB image onto the pointcloud. To do this I have created a stereo calibration using OpenCV on the amplitude image and the RGB image. I have the correction maps saved as .xml files that I load into my program when i need them. The code I have made outputs a pointcloud but it is not correct since not the entire RGB image appears and since the pointcloud comes out as a cone of the same image made smaller and smaller as can be seen in the image below.

Pointcloud error

Here is the code that I have:

void openCVViewer::displayPCLRGBData2(float xData[], float yData[], float depth[], int frameWidth, cv::Mat img)
{
    // Convert ToF image data to cv::Mats to rectify
    cv::Mat depthMap(640, 480, CV_32FC1, depth); //= arrToMat(depth, frameWidth);
    
    // Load maps for rectification
    cv::Mat rmapx, rmapy, lmapx, lmapy, ToFCamMat;
    cv::FileStorage rgbFile;
    rgbFile.open(savePath1 + "RGBStereo.xml", cv::FileStorage::READ);
    if (!rgbFile.isOpened())
    {
        std::cerr << "Failed to find RGBStereo map" << std::endl;
    }
    rgbFile["mapx"] >> rmapx;
    rgbFile["mapy"] >> rmapy;
    rgbFile.release();
    cv::FileStorage tofFile;
    tofFile.open(savePath1 + "ToFStereo.xml", cv::FileStorage::READ);
    if (!tofFile.isOpened())
    {
        std::cerr << "Failed to find ToFStereo map" << std::endl;
    }
    tofFile["mapx"] >> lmapx;
    tofFile["mapy"] >> lmapy;
    tofFile.release();
    
    cv::FileStorage ToFIn;
    ToFIn.open(savePath1 + "ToFIntrinsic.xml", cv::FileStorage::READ);
    //ToFIn.open(savePath1 + "RGBIntrinsic.xml", cv::FileStorage::READ);
    if(!ToFIn.isOpened()){
        std::cerr << "Failed to finde ToFIntrinsic.xml" << std::endl;
    }
    ToFIn["K"] >> ToFCamMat;
    ToFIn.release();

    float cx = ToFCamMat.at<float>(0,2);
    float cy = ToFCamMat.at<float>(1,2);
    float fx = ToFCamMat.at<float>(0,0);
    float fy = ToFCamMat.at<float>(1,1);
    std:: cout << "cx: " << cx << " cy: " << cy << std::endl;

    cv::Mat xcoor(480,640, CV_32F, xData);
    cv::Mat ycoor(480,640, CV_32F, yData);

    // Rectify images
    cv::Mat recy, recx, recImg, recDep;
    cv::remap(depthMap, recDep, lmapx, lmapy, cv::INTER_LINEAR);
    cv::remap(img, recImg, rmapx, rmapy, cv::INTER_LINEAR);
    cv::remap(xcoor, recx, lmapx, lmapy, cv::INTER_LINEAR);
    cv::remap(ycoor, recy, lmapx, lmapy, cv::INTER_LINEAR);
    
    float* depthArr = new float[recDep.cols * recDep.rows];
    std::memcpy(depthArr, recDep.ptr<float>(0), (recDep.cols * recDep.rows) * sizeof(float));

    // Convert color
    cv::cvtColor(recImg, recImg, cv::COLOR_BGR2RGB);

    // Create the aligned point cloud
    pcl::PointCloud<pcl::PointXYZRGB>::Ptr alignedPointCloud(new pcl::PointCloud<pcl::PointXYZRGB>);

    std::cout << "img rows: " << recImg.rows << " img cols: " << recImg.cols << std::endl;
    int size = (recImg.rows * recImg.cols);
    // Loop through each point in the point cloud
    for (size_t i = 0; i < size; ++i) {
        // Retrieve the corresponding pixel coordinates in the corrected RGB image
        int x = static_cast<int>(lmapx.at<float>(i));
        int y = static_cast<int>(lmapy.at<float>(i));

        // Skip points with invalid pixel coordinates
        if (x < 0 || x >= recImg.cols || y < 0 || y >= recImg.rows)
            continue;

        // Retrieve the RGB color at the pixel coordinates from the corrected RGB image
        cv::Vec3b color = recImg.at<cv::Vec3b>(y, x);

        // Calculate the x and y coordinates based on the pixel and depth values
        float px = (x - cx) * depthArr[i] / fx;
        float py = (y - cy) * depthArr[i] / fy;

        // Create a PCL point and assign the coordinates and color
        pcl::PointXYZRGB alignedPoint;
        alignedPoint.x = px;
        alignedPoint.y = py;
        alignedPoint.z = depthArr[i];
        alignedPoint.r = color[2];
        alignedPoint.g = color[1];
        alignedPoint.b = color[0];

        // Add the aligned point to the aligned point cloud
        alignedPointCloud->push_back(alignedPoint);
    }
    // Visualize the point cloud
    pcl::visualization::CloudViewer viewer("Point Cloud Viewer");
    viewer.showCloud(alignedPointCloud);
    while (!viewer.wasStopped()) {
        // Do nothing
    }
}

Solution

  • I figured it out. I had written:

    cv::Mat depthMap(640, 480, CV_32FC1, depth);
    

    and it should have been

    cv::Mat depthMap(480, 640, CV_32FC1, depth);