CameraModel.cpp

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/*
Copyright (c) 2010-2014, Mathieu Labbe - IntRoLab - Universite de Sherbrooke
All rights reserved.

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      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
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      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

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#include <rtabmap/core/CameraModel.h>
#include <rtabmap/utilite/ULogger.h>
#include <rtabmap/utilite/UDirectory.h>
#include <rtabmap/utilite/UFile.h>
#include <opencv2/imgproc/imgproc.hpp>

namespace rtabmap {

CameraModel::CameraModel() :
                P_(cv::Mat::zeros(3, 4, CV_64FC1))
{

}

CameraModel::CameraModel(const std::string & cameraName, const cv::Size & imageSize, const cv::Mat & K, const cv::Mat & D, const cv::Mat & R, const cv::Mat & P) :
                name_(cameraName),
                imageSize_(imageSize),
                K_(K),
                D_(D),
                R_(R),
                P_(P)
{
        UASSERT(!name_.empty());
        UASSERT(imageSize_.width > 0 && imageSize_.height > 0);
        UASSERT(K_.rows == 3 && K_.cols == 3);
        UASSERT(D_.rows == 1 && (D_.cols == 4 || D_.cols == 5 || D_.cols == 8));
        UASSERT(R_.rows == 3 && R_.cols == 3);
        UASSERT(P_.rows == 3 && P_.cols == 4);

        // init rectification map
        UINFO("Initialize rectify map");
        cv::initUndistortRectifyMap(K_, D_, R_, P_, imageSize_, CV_32FC1, mapX_, mapY_);
}

bool CameraModel::load(const std::string & filePath)
{
        K_ = cv::Mat();
        D_ = cv::Mat();
        R_ = cv::Mat();
        P_ = cv::Mat::zeros(3, 4, CV_64FC1);
        mapX_ = cv::Mat();
        mapY_ = cv::Mat();

        if(UFile::exists(filePath))
        {
                UINFO("Reading calibration file \"%s\"", filePath.c_str());
                cv::FileStorage fs(filePath, cv::FileStorage::READ);

                name_ = (int)fs["camera_name"];
                imageSize_.width = (int)fs["image_width"];
                imageSize_.height = (int)fs["image_height"];
                UASSERT(!name_.empty());
                UASSERT(imageSize_.width > 0);
                UASSERT(imageSize_.height > 0);

                // import from ROS calibration format
                cv::FileNode n = fs["camera_matrix"];
                int rows = (int)n["rows"];
                int cols = (int)n["cols"];
                std::vector<double> data;
                n["data"] >> data;
                UASSERT(rows*cols == (int)data.size());
                UASSERT(rows == 3 && cols == 3);
                K_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                n = fs["distortion_coefficients"];
                rows = (int)n["rows"];
                cols = (int)n["cols"];
                data.clear();
                n["data"] >> data;
                UASSERT(rows*cols == (int)data.size());
                UASSERT(rows == 1 && (cols == 4 || cols == 5 || cols == 8));
                D_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                n = fs["rectification_matrix"];
                rows = (int)n["rows"];
                cols = (int)n["cols"];
                data.clear();
                n["data"] >> data;
                UASSERT(rows*cols == (int)data.size());
                UASSERT(rows == 3 && cols == 3);
                R_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                n = fs["projection_matrix"];
                rows = (int)n["rows"];
                cols = (int)n["cols"];
                data.clear();
                n["data"] >> data;
                UASSERT(rows*cols == (int)data.size());
                UASSERT(rows == 3 && cols == 4);
                P_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                fs.release();

                // init rectification map
                UINFO("Initialize rectify map");
                cv::initUndistortRectifyMap(K_, D_, R_, P_, imageSize_, CV_32FC1, mapX_, mapY_);

                return true;
        }
        return false;
}

bool CameraModel::save(const std::string & filePath)
{
        if(!filePath.empty() && !name_.empty() && !K_.empty() && !D_.empty() && !R_.empty() && !P_.empty())
        {
                UINFO("Saving calibration to file \"%s\"", filePath.c_str());
                cv::FileStorage fs(filePath, cv::FileStorage::WRITE);

                // export in ROS calibration format

                fs << "camera_name" << name_;
                fs << "image_width" << imageSize_.width;
                fs << "image_height" << imageSize_.height;

                fs << "camera_matrix" << "{";
                fs << "rows" << K_.rows;
                fs << "cols" << K_.cols;
                fs << "data" << std::vector<double>((double*)K_.data, ((double*)K_.data)+(K_.rows*K_.cols));
                fs << "}";

                fs << "distortion_coefficients" << "{";
                fs << "rows" << D_.rows;
                fs << "cols" << D_.cols;
                fs << "data" << std::vector<double>((double*)D_.data, ((double*)D_.data)+(D_.rows*D_.cols));
                fs << "}";

                fs << "rectification_matrix" << "{";
                fs << "rows" << R_.rows;
                fs << "cols" << R_.cols;
                fs << "data" << std::vector<double>((double*)R_.data, ((double*)R_.data)+(R_.rows*R_.cols));
                fs << "}";

                fs << "projection_matrix" << "{";
                fs << "rows" << P_.rows;
                fs << "cols" << P_.cols;
                fs << "data" << std::vector<double>((double*)P_.data, ((double*)P_.data)+(P_.rows*P_.cols));
                fs << "}";

                fs.release();

                return true;
        }
        return false;
}

cv::Mat CameraModel::rectifyImage(const cv::Mat & raw, int interpolation) const
{
        if(!mapX_.empty() && !mapY_.empty())
        {
                cv::Mat rectified;
                cv::remap(raw, rectified, mapX_, mapY_, interpolation);
                return rectified;
        }
        else
        {
                return raw.clone();
        }
}

//inspired from https://github.com/code-iai/iai_kinect2/blob/master/depth_registration/src/depth_registration_cpu.cpp
cv::Mat CameraModel::rectifyDepth(const cv::Mat & raw) const
{
        UASSERT(raw.type() == CV_16UC1);
        if(!mapX_.empty() && !mapY_.empty())
        {
                cv::Mat rectified = cv::Mat::zeros(mapX_.rows, mapX_.cols, raw.type());
                for(int y=0; y<mapX_.rows; ++y)
                {
                        for(int x=0; x<mapX_.cols; ++x)
                        {
                                cv::Point2f pt(mapX_.at<float>(y,x), mapY_.at<float>(y,x));
                                int xL = (int)floor(pt.x);
                                int xH = (int)ceil(pt.x);
                                int yL = (int)floor(pt.y);
                                int yH = (int)ceil(pt.y);
                                if(xL >= 0 && yL >= 0 && xH < raw.cols && yH < raw.rows)
                                {
                                        const unsigned short & pLT = raw.at<unsigned short>(yL, xL);
                                        const unsigned short & pRT = raw.at<unsigned short>(yL, xH);
                                        const unsigned short & pLB = raw.at<unsigned short>(yH, xL);
                                        const unsigned short & pRB = raw.at<unsigned short>(yH, xH);
                                        if(pLT > 0 && pRT > 0 && pLB > 0 && pRB > 0)
                                        {
                                                unsigned short avg = (pLT + pRT + pLB + pRB) / 4;
                                                unsigned short thres = 0.01 * avg;
                                                if( abs(pLT - avg) < thres &&
                                                        abs(pRT - avg) < thres &&
                                                        abs(pLB - avg) < thres &&
                                                        abs(pRB - avg) < thres)
                                                {
                                                        //bilinear interpolation
                                                        float a = pt.x - (float)xL;
                                                        float c = pt.y - (float)yL;

                                                        //http://stackoverflow.com/questions/13299409/how-to-get-the-image-pixel-at-real-locations-in-opencv
                                                        rectified.at<unsigned short>(y,x) =
                                                                        (raw.at<unsigned short>(yL, xL) * (1.f - a) + raw.at<unsigned short>(yL, xH) * a) * (1.f - c) +
                                                                        (raw.at<unsigned short>(yH, xL) * (1.f - a) + raw.at<unsigned short>(yH, xH) * a) * c;
                                                }
                                        }
                                }
                        }
                }
                return rectified;
        }
        else
        {
                return raw.clone();
        }
}

//
//StereoCameraModel
//
bool StereoCameraModel::load(const std::string & directory, const std::string & cameraName)
{
        name_ = cameraName;
        if(left_.load(directory+"/"+cameraName+"_left.yaml") && right_.load(directory+"/"+cameraName+"_right.yaml"))
        {
                //load rotation, translation
                R_ = cv::Mat();
                T_ = cv::Mat();

                std::string filePath = directory+"/"+cameraName+"_pose.yaml";
                if(UFile::exists(filePath))
                {
                        UINFO("Reading stereo calibration file \"%s\"", filePath.c_str());
                        cv::FileStorage fs(filePath, cv::FileStorage::READ);

                        name_ = (int)fs["camera_name"];

                        // import from ROS calibration format
                        cv::FileNode n = fs["rotation_matrix"];
                        int rows = (int)n["rows"];
                        int cols = (int)n["cols"];
                        std::vector<double> data;
                        n["data"] >> data;
                        UASSERT(rows*cols == (int)data.size());
                        UASSERT(rows == 3 && cols == 3);
                        R_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                        n = fs["translation_matrix"];
                        rows = (int)n["rows"];
                        cols = (int)n["cols"];
                        data.clear();
                        n["data"] >> data;
                        UASSERT(rows*cols == (int)data.size());
                        UASSERT(rows == 3 && cols == 1);
                        T_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                        n = fs["essential_matrix"];
                        rows = (int)n["rows"];
                        cols = (int)n["cols"];
                        data.clear();
                        n["data"] >> data;
                        UASSERT(rows*cols == (int)data.size());
                        UASSERT(rows == 3 && cols == 3);
                        E_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                        n = fs["fundamental_matrix"];
                        rows = (int)n["rows"];
                        cols = (int)n["cols"];
                        data.clear();
                        n["data"] >> data;
                        UASSERT(rows*cols == (int)data.size());
                        UASSERT(rows == 3 && cols == 3);
                        F_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();

                        fs.release();

                        return true;
                }
        }
        return false;
}
bool StereoCameraModel::save(const std::string & directory, const std::string & cameraName)
{
        if(left_.save(directory+"/"+cameraName+"_left.yaml") && right_.save(directory+"/"+cameraName+"_right.yaml"))
        {
                std::string filePath = directory+"/"+cameraName+"_pose.yaml";
                if(!filePath.empty() && !name_.empty() && !R_.empty() && !T_.empty())
                {
                        UINFO("Saving stereo calibration to file \"%s\"", filePath.c_str());
                        cv::FileStorage fs(filePath, cv::FileStorage::WRITE);

                        // export in ROS calibration format

                        fs << "camera_name" << name_;

                        fs << "rotation_matrix" << "{";
                        fs << "rows" << R_.rows;
                        fs << "cols" << R_.cols;
                        fs << "data" << std::vector<double>((double*)R_.data, ((double*)R_.data)+(R_.rows*R_.cols));
                        fs << "}";

                        fs << "translation_matrix" << "{";
                        fs << "rows" << T_.rows;
                        fs << "cols" << T_.cols;
                        fs << "data" << std::vector<double>((double*)T_.data, ((double*)T_.data)+(T_.rows*T_.cols));
                        fs << "}";

                        fs << "essential_matrix" << "{";
                        fs << "rows" << E_.rows;
                        fs << "cols" << E_.cols;
                        fs << "data" << std::vector<double>((double*)E_.data, ((double*)E_.data)+(E_.rows*E_.cols));
                        fs << "}";

                        fs << "fundamental_matrix" << "{";
                        fs << "rows" << F_.rows;
                        fs << "cols" << F_.cols;
                        fs << "data" << std::vector<double>((double*)F_.data, ((double*)F_.data)+(F_.rows*F_.cols));
                        fs << "}";

                        fs.release();

                        return true;
                }
        }
        return false;
}

Transform StereoCameraModel::transform() const
{
        if(!R_.empty() && !T_.empty())
        {
                return Transform(
                                R_.at<double>(0,0), R_.at<double>(0,1), R_.at<double>(0,2), T_.at<double>(0),
                                R_.at<double>(1,0), R_.at<double>(1,1), R_.at<double>(1,2), T_.at<double>(1),
                                R_.at<double>(2,0), R_.at<double>(2,1), R_.at<double>(2,2), T_.at<double>(2));
        }
        return Transform();
}

} /* namespace rtabmap */