opencv/apps/interactive-calibration/calibController.cpp

#include "calibController.hpp"

#include <algorithm>
#include <cmath>
#include <ctime>
#include <opencv2/calib3d.hpp>
#include <opencv2/imgproc.hpp>

double calib::calibController::estimateCoverageQuality()
{
    int gridSize = 10;
    int xGridStep = mCalibData->imageSize.width / gridSize;
    int yGridStep = mCalibData->imageSize.height / gridSize;
    std::vector<int> pointsInCell(gridSize*gridSize);

    std::fill(pointsInCell.begin(), pointsInCell.end(), 0);

    for(std::vector<std::vector<cv::Point2f> >::iterator it = mCalibData->imagePoints.begin(); it != mCalibData->imagePoints.end(); ++it)
        for(std::vector<cv::Point2f>::iterator pointIt = (*it).begin(); pointIt != (*it).end(); ++pointIt) {
            int i = (int)((*pointIt).x / xGridStep);
            int j = (int)((*pointIt).y / yGridStep);
            pointsInCell[i*gridSize + j]++;
        }

    for(std::vector<cv::Mat>::iterator it = mCalibData->allCharucoCorners.begin(); it != mCalibData->allCharucoCorners.end(); ++it)
        for(int l = 0; l < (*it).size[0]; l++) {
            int i = (int)((*it).at<float>(l, 0) / xGridStep);
            int j = (int)((*it).at<float>(l, 1) / yGridStep);
            pointsInCell[i*gridSize + j]++;
        }

    cv::Mat mean, stdDev;
    cv::meanStdDev(pointsInCell, mean, stdDev);

    return mean.at<double>(0) / (stdDev.at<double>(0) + 1e-7);
}

calib::calibController::calibController()
{
    mCalibFlags = 0;
}

calib::calibController::calibController(cv::Ptr<calib::calibrationData> data, int initialFlags, bool autoTuning, int minFramesNum) :
    mCalibData(data)
{
    mCalibFlags = initialFlags;
    mNeedTuning = autoTuning;
    mMinFramesNum = minFramesNum;
    mConfIntervalsState = false;
    mCoverageQualityState = false;
}

void calib::calibController::updateState()
{
    if(mCalibData->cameraMatrix.total()) {
        const double relErrEps = 0.05;
        bool fConfState = false, cConfState = false, dConfState = true;
        if(sigmaMult*mCalibData->stdDeviations.at<double>(0) / mCalibData->cameraMatrix.at<double>(0,0) < relErrEps &&
                sigmaMult*mCalibData->stdDeviations.at<double>(1) / mCalibData->cameraMatrix.at<double>(1,1) < relErrEps)
            fConfState = true;
        if(sigmaMult*mCalibData->stdDeviations.at<double>(2) / mCalibData->cameraMatrix.at<double>(0,2) < relErrEps &&
                sigmaMult*mCalibData->stdDeviations.at<double>(3) / mCalibData->cameraMatrix.at<double>(1,2) < relErrEps)
            cConfState = true;

        for(int i = 0; i < 5; i++)
            if(mCalibData->stdDeviations.at<double>(4+i) / fabs(mCalibData->distCoeffs.at<double>(i)) > 1)
                dConfState = false;

        mConfIntervalsState = fConfState && cConfState && dConfState;
    }

    if(getFramesNumberState())
        mCoverageQualityState = estimateCoverageQuality() > 1.8 ? true : false;

    if (getFramesNumberState() && mNeedTuning) {
        if( !(mCalibFlags & cv::CALIB_FIX_ASPECT_RATIO) &&
            mCalibData->cameraMatrix.total()) {
            double fDiff = fabs(mCalibData->cameraMatrix.at<double>(0,0) -
                                mCalibData->cameraMatrix.at<double>(1,1));

            if (fDiff < 3*mCalibData->stdDeviations.at<double>(0) &&
                    fDiff < 3*mCalibData->stdDeviations.at<double>(1)) {
                mCalibFlags |= cv::CALIB_FIX_ASPECT_RATIO;
                mCalibData->cameraMatrix.at<double>(0,0) =
                        mCalibData->cameraMatrix.at<double>(1,1);
            }
        }

        if(!(mCalibFlags & cv::CALIB_ZERO_TANGENT_DIST)) {
            const double eps = 0.005;
            if(fabs(mCalibData->distCoeffs.at<double>(2)) < eps &&
                    fabs(mCalibData->distCoeffs.at<double>(3)) < eps)
                mCalibFlags |= cv::CALIB_ZERO_TANGENT_DIST;
        }

        if(!(mCalibFlags & cv::CALIB_FIX_K1)) {
            const double eps = 0.005;
            if(fabs(mCalibData->distCoeffs.at<double>(0)) < eps)
                mCalibFlags |= cv::CALIB_FIX_K1;
        }

        if(!(mCalibFlags & cv::CALIB_FIX_K2)) {
            const double eps = 0.005;
            if(fabs(mCalibData->distCoeffs.at<double>(1)) < eps)
                mCalibFlags |= cv::CALIB_FIX_K2;
        }

        if(!(mCalibFlags & cv::CALIB_FIX_K3)) {
            const double eps = 0.005;
            if(fabs(mCalibData->distCoeffs.at<double>(4)) < eps)
                mCalibFlags |= cv::CALIB_FIX_K3;
        }

    }
}

bool calib::calibController::getCommonCalibrationState() const
{
    int rating = (int)getFramesNumberState() + (int)getConfidenceIntrervalsState() +
            (int)getRMSState() + (int)mCoverageQualityState;
    return rating == 4;
}

bool calib::calibController::getFramesNumberState() const
{
    return std::max(mCalibData->imagePoints.size(), mCalibData->allCharucoCorners.size()) > mMinFramesNum;
}

bool calib::calibController::getConfidenceIntrervalsState() const
{
    return mConfIntervalsState;
}

bool calib::calibController::getRMSState() const
{
    return mCalibData->totalAvgErr < 0.5;
}

int calib::calibController::getNewFlags() const
{
    return mCalibFlags;
}


//////////////////// calibDataController

double calib::calibDataController::estimateGridSubsetQuality(size_t excludedIndex)
{
    {
        int gridSize = 10;
        int xGridStep = mCalibData->imageSize.width / gridSize;
        int yGridStep = mCalibData->imageSize.height / gridSize;
        std::vector<int> pointsInCell(gridSize*gridSize);

        std::fill(pointsInCell.begin(), pointsInCell.end(), 0);

        for(size_t k = 0; k < mCalibData->imagePoints.size(); k++)
            if(k != excludedIndex)
                for(std::vector<cv::Point2f>::iterator pointIt = mCalibData->imagePoints[k].begin(); pointIt != mCalibData->imagePoints[k].end(); ++pointIt) {
                    int i = (int)((*pointIt).x / xGridStep);
                    int j = (int)((*pointIt).y / yGridStep);
                    pointsInCell[i*gridSize + j]++;
                }

        for(size_t k = 0; k < mCalibData->allCharucoCorners.size(); k++)
            if(k != excludedIndex)
                for(int l = 0; l <  mCalibData->allCharucoCorners[k].size[0]; l++) {
                    int i = (int)(mCalibData->allCharucoCorners[k].at<float>(l, 0) / xGridStep);
                    int j = (int)(mCalibData->allCharucoCorners[k].at<float>(l, 1) / yGridStep);
                    pointsInCell[i*gridSize + j]++;
                }

        cv::Mat mean, stdDev;
        cv::meanStdDev(pointsInCell, mean, stdDev);

        return mean.at<double>(0) / (stdDev.at<double>(0) + 1e-7);
    }
}

calib::calibDataController::calibDataController(cv::Ptr<calib::calibrationData> data, int maxFrames, double convParameter) :
    mCalibData(data), mParamsFileName("CamParams.xml")
{
    mMaxFramesNum = maxFrames;
    mAlpha = convParameter;
}

calib::calibDataController::calibDataController()
{

}

void calib::calibDataController::filterFrames()
{
    size_t numberOfFrames = std::max(mCalibData->allCharucoIds.size(), mCalibData->imagePoints.size());
    CV_Assert(numberOfFrames == mCalibData->perViewErrors.total());
    if(numberOfFrames >= mMaxFramesNum) {

        double worstValue = -HUGE_VAL, maxQuality = estimateGridSubsetQuality(numberOfFrames);
        size_t worstElemIndex = 0;
        for(size_t i = 0; i < numberOfFrames; i++) {
            double gridQDelta = estimateGridSubsetQuality(i) - maxQuality;
            double currentValue = mCalibData->perViewErrors.at<double>((int)i)*mAlpha + gridQDelta*(1. - mAlpha);
            if(currentValue > worstValue) {
                worstValue = currentValue;
                worstElemIndex = i;
            }
        }
        showOverlayMessage(cv::format("Frame %d is worst", worstElemIndex + 1));

        if(mCalibData->imagePoints.size()) {
            mCalibData->imagePoints.erase(mCalibData->imagePoints.begin() + worstElemIndex);
            mCalibData->objectPoints.erase(mCalibData->objectPoints.begin() + worstElemIndex);
        }
        else {
            mCalibData->allCharucoCorners.erase(mCalibData->allCharucoCorners.begin() + worstElemIndex);
            mCalibData->allCharucoIds.erase(mCalibData->allCharucoIds.begin() + worstElemIndex);
        }

        cv::Mat newErrorsVec = cv::Mat((int)numberOfFrames - 1, 1, CV_64F);
        std::copy(mCalibData->perViewErrors.ptr<double>(0),
                  mCalibData->perViewErrors.ptr<double>((int)worstElemIndex), newErrorsVec.ptr<double>(0));
        std::copy(mCalibData->perViewErrors.ptr<double>((int)worstElemIndex + 1), mCalibData->perViewErrors.ptr<double>((int)numberOfFrames),
                    newErrorsVec.ptr<double>((int)worstElemIndex));
        mCalibData->perViewErrors = newErrorsVec;
    }
}

void calib::calibDataController::setParametersFileName(const std::string &name)
{
    mParamsFileName = name;
}

void calib::calibDataController::deleteLastFrame()
{
    if( !mCalibData->imagePoints.empty()) {
        mCalibData->imagePoints.pop_back();
        mCalibData->objectPoints.pop_back();
    }

    if (!mCalibData->allCharucoCorners.empty()) {
        mCalibData->allCharucoCorners.pop_back();
        mCalibData->allCharucoIds.pop_back();
    }

    if(!mParamsStack.empty()) {
        mCalibData->cameraMatrix = (mParamsStack.top()).cameraMatrix;
        mCalibData->distCoeffs = (mParamsStack.top()).distCoeffs;
        mCalibData->stdDeviations = (mParamsStack.top()).stdDeviations;
        mCalibData->totalAvgErr = (mParamsStack.top()).avgError;
        mParamsStack.pop();
    }
}

void calib::calibDataController::rememberCurrentParameters()
{
    cv::Mat oldCameraMat, oldDistcoeefs, oldStdDevs;
    mCalibData->cameraMatrix.copyTo(oldCameraMat);
    mCalibData->distCoeffs.copyTo(oldDistcoeefs);
    mCalibData->stdDeviations.copyTo(oldStdDevs);
    mParamsStack.push(cameraParameters(oldCameraMat, oldDistcoeefs, oldStdDevs, mCalibData->totalAvgErr));
}

void calib::calibDataController::deleteAllData()
{
    mCalibData->imagePoints.clear();
    mCalibData->objectPoints.clear();
    mCalibData->allCharucoCorners.clear();
    mCalibData->allCharucoIds.clear();
    mCalibData->cameraMatrix = mCalibData->distCoeffs = cv::Mat();
    mParamsStack = std::stack<cameraParameters>();
    rememberCurrentParameters();
}

bool calib::calibDataController::saveCurrentCameraParameters() const
{
    bool success = false;
    if(mCalibData->cameraMatrix.total()) {
            cv::FileStorage parametersWriter(mParamsFileName, cv::FileStorage::WRITE);
            if(parametersWriter.isOpened()) {
                time_t rawtime;
                time(&rawtime);
                char buf[256];
                strftime(buf, sizeof(buf)-1, "%c", localtime(&rawtime));

                parametersWriter << "calibrationDate" << buf;
                parametersWriter << "framesCount" << std::max((int)mCalibData->objectPoints.size(), (int)mCalibData->allCharucoCorners.size());
                parametersWriter << "cameraResolution" << mCalibData->imageSize;
                parametersWriter << "cameraMatrix" << mCalibData->cameraMatrix;
                parametersWriter << "cameraMatrix_std_dev" << mCalibData->stdDeviations.rowRange(cv::Range(0, 4));
                parametersWriter << "dist_coeffs" << mCalibData->distCoeffs;
                parametersWriter << "dist_coeffs_std_dev" << mCalibData->stdDeviations.rowRange(cv::Range(4, 9));
                parametersWriter << "avg_reprojection_error" << mCalibData->totalAvgErr;

                parametersWriter.release();
                success = true;
        }
    }
    return success;
}

void calib::calibDataController::printParametersToConsole(std::ostream &output) const
{
    const char* border = "---------------------------------------------------";
    output << border << std::endl;
    output << "Frames used for calibration: " << std::max(mCalibData->objectPoints.size(), mCalibData->allCharucoCorners.size())
           << " \t RMS = " << mCalibData->totalAvgErr << std::endl;
    if(mCalibData->cameraMatrix.at<double>(0,0) == mCalibData->cameraMatrix.at<double>(1,1))
        output << "F = " << mCalibData->cameraMatrix.at<double>(1,1) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(1) << std::endl;
    else
        output << "Fx = " << mCalibData->cameraMatrix.at<double>(0,0) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(0) << " \t "
               << "Fy = " << mCalibData->cameraMatrix.at<double>(1,1) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(1) << std::endl;
    output << "Cx = " << mCalibData->cameraMatrix.at<double>(0,2) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(2) << " \t"
           << "Cy = " << mCalibData->cameraMatrix.at<double>(1,2) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(3) << std::endl;
    output << "K1 = " << mCalibData->distCoeffs.at<double>(0) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(4) << std::endl;
    output << "K2 = " << mCalibData->distCoeffs.at<double>(1) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(5) << std::endl;
    output << "K3 = " << mCalibData->distCoeffs.at<double>(4) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(8) << std::endl;
    output << "TD1 = " << mCalibData->distCoeffs.at<double>(2) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(6) << std::endl;
    output << "TD2 = " << mCalibData->distCoeffs.at<double>(3) << " +- " << sigmaMult*mCalibData->stdDeviations.at<double>(7) << std::endl;
}

void calib::calibDataController::updateUndistortMap()
{
    cv::initUndistortRectifyMap(mCalibData->cameraMatrix, mCalibData->distCoeffs, cv::noArray(),
                                cv::getOptimalNewCameraMatrix(mCalibData->cameraMatrix, mCalibData->distCoeffs, mCalibData->imageSize, 0.0, mCalibData->imageSize),
                                mCalibData->imageSize, CV_16SC2, mCalibData->undistMap1, mCalibData->undistMap2);

}