// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.

#include "test_precomp.hpp"
#include <opencv2/ts/cuda_test.hpp> // EXPECT_MAT_NEAR
#include "opencv2/videoio.hpp"

namespace opencv_test { namespace {

class fisheyeTest : public ::testing::Test {

protected:
    const static cv::Size imageSize;
    const static cv::Matx33d K;
    const static cv::Vec4d D;
    std::string datasets_repository_path;

    virtual void SetUp() {
        datasets_repository_path = combine(cvtest::TS::ptr()->get_data_path(), "cv/cameracalibration/fisheye");
    }

protected:
    std::string combine(const std::string& _item1, const std::string& _item2);
};

const cv::Size fisheyeTest::imageSize(1280, 800);

const cv::Matx33d fisheyeTest::K(558.478087865323,               0, 620.458515360843,
                              0, 560.506767351568, 381.939424848348,
                              0,               0,                1);

const cv::Vec4d fisheyeTest::D(-0.0014613319981768, -0.00329861110580401, 0.00605760088590183, -0.00374209380722371);

std::string fisheyeTest::combine(const std::string& _item1, const std::string& _item2)
{
    std::string item1 = _item1, item2 = _item2;
    std::replace(item1.begin(), item1.end(), '\\', '/');
    std::replace(item2.begin(), item2.end(), '\\', '/');

    if (item1.empty())
        return item2;

    if (item2.empty())
        return item1;

    char last = item1[item1.size()-1];
    return item1 + (last != '/' ? "/" : "") + item2;
}

TEST_F(fisheyeTest, projectPoints)
{
    double cols = this->imageSize.width,
           rows = this->imageSize.height;

    const int N = 20;
    cv::Mat distorted0(1, N*N, CV_64FC2), undist1, undist2, distorted1, distorted2;
    undist2.create(distorted0.size(), CV_MAKETYPE(distorted0.depth(), 3));
    cv::Vec2d* pts = distorted0.ptr<cv::Vec2d>();

    cv::Vec2d c(this->K(0, 2), this->K(1, 2));
    for(int y = 0, k = 0; y < N; ++y)
        for(int x = 0; x < N; ++x)
        {
            cv::Vec2d point(x*cols/(N-1.f), y*rows/(N-1.f));
            pts[k++] = (point - c) * 0.85 + c;
        }

    cv::fisheye::undistortPoints(distorted0, undist1, this->K, this->D);

    cv::Vec2d* u1 = undist1.ptr<cv::Vec2d>();
    cv::Vec3d* u2 = undist2.ptr<cv::Vec3d>();
    for(int i = 0; i  < (int)distorted0.total(); ++i)
        u2[i] = cv::Vec3d(u1[i][0], u1[i][1], 1.0);

    cv::fisheye::distortPoints(undist1, distorted1, this->K, this->D);
    cv::fisheye::projectPoints(undist2, distorted2, cv::Vec3d::all(0), cv::Vec3d::all(0), this->K, this->D);

    EXPECT_MAT_NEAR(distorted0, distorted1, 1e-10);
    EXPECT_MAT_NEAR(distorted0, distorted2, 1e-10);
}

TEST_F(fisheyeTest, distortUndistortPoints)
{
    int width = imageSize.width;
    int height = imageSize.height;

    /* Create test points */
    std::vector<cv::Point2d> points0Vector;
    cv::Mat principalPoints = (cv::Mat_<double>(5, 2) << K(0, 2), K(1, 2), // (cx, cy)
                                                                    /* Image corners */
                                                                    0, 0,
                                                                    0, height,
                                                                    width, 0,
                                                                    width, height
                                                                    );

    /* Random points inside image */
    cv::Mat xy[2] = {};
    xy[0].create(100, 1, CV_64F);
    theRNG().fill(xy[0], cv::RNG::UNIFORM, 0, width); // x
    xy[1].create(100, 1, CV_64F);
    theRNG().fill(xy[1], cv::RNG::UNIFORM, 0, height); // y

    cv::Mat randomPoints;
    merge(xy, 2, randomPoints);

    cv::Mat points0;
    cv::vconcat(principalPoints.reshape(2), randomPoints, points0);

    /* Test with random D set */
    for (size_t i = 0; i < 10; ++i) {
        cv::Mat distortion(1, 4, CV_64F);
        theRNG().fill(distortion, cv::RNG::UNIFORM, -0.00001, 0.00001);

        /* Distort -> Undistort */
        cv::Mat distortedPoints;
        cv::fisheye::distortPoints(points0, distortedPoints, K, distortion);
        cv::Mat undistortedPoints;
        cv::fisheye::undistortPoints(distortedPoints, undistortedPoints, K, distortion);

        EXPECT_MAT_NEAR(points0, undistortedPoints, 1e-8);

        /* Undistort -> Distort */
        cv::fisheye::undistortPoints(points0, undistortedPoints, K, distortion);
        cv::fisheye::distortPoints(undistortedPoints, distortedPoints, K, distortion);

        EXPECT_MAT_NEAR(points0, distortedPoints, 1e-8);
    }
}

TEST_F(fisheyeTest, undistortImage)
{
    // we use it to reduce patch size for images in testdata
    auto throwAwayHalf = [](Mat img)
    {
        int whalf = img.cols / 2, hhalf = img.rows / 2;
        Rect tl(0, 0, whalf, hhalf), br(whalf, hhalf, whalf, hhalf);
        img(tl) = 0;
        img(br) = 0;
    };

    cv::Matx33d theK = this->K;
    cv::Mat theD = cv::Mat(this->D);
    std::string file = combine(datasets_repository_path, "/calib-3_stereo_from_JY/left/stereo_pair_014.jpg");
    cv::Matx33d newK = theK;
    cv::Mat distorted = cv::imread(file), undistorted;
    {
        newK(0, 0) = 100;
        newK(1, 1) = 100;
        cv::fisheye::undistortImage(distorted, undistorted, theK, theD, newK);
        std::string imageFilename = combine(datasets_repository_path, "new_f_100.png");
        cv::Mat correct = cv::imread(imageFilename);
        ASSERT_FALSE(correct.empty()) << "Correct image " << imageFilename.c_str() << " can not be read" << std::endl;

        throwAwayHalf(correct);
        throwAwayHalf(undistorted);

        EXPECT_MAT_NEAR(correct, undistorted, 1e-10);
    }
    {
        double balance = 1.0;
        cv::fisheye::estimateNewCameraMatrixForUndistortRectify(theK, theD, distorted.size(), cv::noArray(), newK, balance);
        cv::fisheye::undistortImage(distorted, undistorted, theK, theD, newK);
        std::string imageFilename = combine(datasets_repository_path, "balance_1.0.png");
        cv::Mat correct = cv::imread(imageFilename);
        ASSERT_FALSE(correct.empty()) << "Correct image " << imageFilename.c_str() << " can not be read" << std::endl;

        throwAwayHalf(correct);
        throwAwayHalf(undistorted);

        EXPECT_MAT_NEAR(correct, undistorted, 1e-10);
    }

    {
        double balance = 0.0;
        cv::fisheye::estimateNewCameraMatrixForUndistortRectify(theK, theD, distorted.size(), cv::noArray(), newK, balance);
        cv::fisheye::undistortImage(distorted, undistorted, theK, theD, newK);
        std::string imageFilename = combine(datasets_repository_path, "balance_0.0.png");
        cv::Mat correct = cv::imread(imageFilename);
        ASSERT_FALSE(correct.empty()) << "Correct image " << imageFilename.c_str() << " can not be read" << std::endl;

        throwAwayHalf(correct);
        throwAwayHalf(undistorted);

        EXPECT_MAT_NEAR(correct, undistorted, 1e-10);
    }
}

TEST_F(fisheyeTest, undistortAndDistortImage)
{
    cv::Matx33d K_src = this->K;
    cv::Mat D_src = cv::Mat(this->D);
    std::string file = combine(datasets_repository_path, "/calib-3_stereo_from_JY/left/stereo_pair_014.jpg");
    cv::Matx33d K_dst = K_src;
    cv::Mat image = cv::imread(file), image_projected;
    cv::Vec4d D_dst_vec (-1.0, 0.0, 0.0, 0.0);
    cv::Mat D_dst = cv::Mat(D_dst_vec);

    int imageWidth = (int)this->imageSize.width;
    int imageHeight = (int)this->imageSize.height;

    cv::Mat imagePoints(imageHeight, imageWidth, CV_32FC2), undPoints, distPoints;
    cv::Vec2f* pts = imagePoints.ptr<cv::Vec2f>();

    for(int y = 0, k = 0; y < imageHeight; ++y)
    {
        for(int x = 0; x < imageWidth; ++x)
        {
            cv::Vec2f point((float)x, (float)y);
            pts[k++] = point;
        }
    }

    cv::fisheye::undistortPoints(imagePoints, undPoints, K_dst, D_dst);
    cv::fisheye::distortPoints(undPoints, distPoints, K_src, D_src);
    cv::remap(image, image_projected, distPoints, cv::noArray(), cv::INTER_LINEAR);

    float dx, dy, r_sq;
    float R_MAX = 250;
    float imageCenterX = (float)imageWidth / 2;
    float imageCenterY = (float)imageHeight / 2;

    cv::Mat undPointsGt(imageHeight, imageWidth, CV_32FC2);
    cv::Mat imageGt(imageHeight, imageWidth, CV_8UC3);

    for(int y = 0; y < imageHeight; ++y)
    {
        for(int x = 0; x < imageWidth; ++x)
        {
            dx = x - imageCenterX;
            dy = y - imageCenterY;
            r_sq = dy * dy + dx * dx;

            Vec2f & und_vec = undPoints.at<Vec2f>(y,x);
            Vec3b & pixel = image_projected.at<Vec3b>(y,x);

            Vec2f & undist_vec_gt = undPointsGt.at<Vec2f>(y,x);
            Vec3b & pixel_gt = imageGt.at<Vec3b>(y,x);

            if (r_sq > R_MAX * R_MAX)
            {

                undist_vec_gt[0] = -1e6;
                undist_vec_gt[1] = -1e6;

                pixel_gt[0] = 0;
                pixel_gt[1] = 0;
                pixel_gt[2] = 0;
            }
            else
            {
                undist_vec_gt[0] = und_vec[0];
                undist_vec_gt[1] = und_vec[1];

                pixel_gt[0] = pixel[0];
                pixel_gt[1] = pixel[1];
                pixel_gt[2] = pixel[2];
            }

        }
    }

    EXPECT_MAT_NEAR(undPoints, undPointsGt, 1e-10);
    EXPECT_MAT_NEAR(image_projected, imageGt, 1e-10);

    Vec2f dist_point_1 = distPoints.at<Vec2f>(400, 640);
    Vec2f dist_point_1_gt(640.044f, 400.041f);

    Vec2f dist_point_2 = distPoints.at<Vec2f>(400, 440);
    Vec2f dist_point_2_gt(409.731f, 403.029f);

    Vec2f dist_point_3 = distPoints.at<Vec2f>(200, 640);
    Vec2f dist_point_3_gt(643.341f, 168.896f);

    Vec2f dist_point_4 = distPoints.at<Vec2f>(300, 480);
    Vec2f dist_point_4_gt(463.402f, 290.317f);

    Vec2f dist_point_5 = distPoints.at<Vec2f>(550, 750);
    Vec2f dist_point_5_gt(797.51f, 611.637f);

    EXPECT_MAT_NEAR(dist_point_1, dist_point_1_gt, 1e-2);
    EXPECT_MAT_NEAR(dist_point_2, dist_point_2_gt, 1e-2);
    EXPECT_MAT_NEAR(dist_point_3, dist_point_3_gt, 1e-2);
    EXPECT_MAT_NEAR(dist_point_4, dist_point_4_gt, 1e-2);
    EXPECT_MAT_NEAR(dist_point_5, dist_point_5_gt, 1e-2);

    // Add the "--test_debug" to arguments for file output
    if (cvtest::debugLevel > 0)
        cv::imwrite(combine(datasets_repository_path, "new_distortion.png"), image_projected);
}

TEST_F(fisheyeTest, jacobians)
{
    int n = 10;
    cv::Mat X(1, n, CV_64FC3);
    cv::Mat om(3, 1, CV_64F), theT(3, 1, CV_64F);
    cv::Mat f(2, 1, CV_64F), c(2, 1, CV_64F);
    cv::Mat k(4, 1, CV_64F);
    double alpha;

    cv::RNG r;

    r.fill(X, cv::RNG::NORMAL, 2, 1);
    X = cv::abs(X) * 10;

    r.fill(om, cv::RNG::NORMAL, 0, 1);
    om = cv::abs(om);

    r.fill(theT, cv::RNG::NORMAL, 0, 1);
    theT = cv::abs(theT); theT.at<double>(2) = 4; theT *= 10;

    r.fill(f, cv::RNG::NORMAL, 0, 1);
    f = cv::abs(f) * 1000;

    r.fill(c, cv::RNG::NORMAL, 0, 1);
    c = cv::abs(c) * 1000;

    r.fill(k, cv::RNG::NORMAL, 0, 1);
    k*= 0.5;

    alpha = 0.01*r.gaussian(1);

    cv::Mat x1, x2, xpred;
    cv::Matx33d theK(f.at<double>(0), alpha * f.at<double>(0), c.at<double>(0),
                     0,            f.at<double>(1), c.at<double>(1),
                     0,            0,    1);

    cv::Mat jacobians;
    cv::fisheye::projectPoints(X, x1, om, theT, theK, k, alpha, jacobians);

    //test on T:
    cv::Mat dT(3, 1, CV_64FC1);
    r.fill(dT, cv::RNG::NORMAL, 0, 1);
    dT *= 1e-9*cv::norm(theT);
    cv::Mat T2 = theT + dT;
    cv::fisheye::projectPoints(X, x2, om, T2, theK, k, alpha, cv::noArray());
    xpred = x1 + cv::Mat(jacobians.colRange(11,14) * dT).reshape(2, 1);
    CV_Assert (cv::norm(x2 - xpred) < 1e-10);

    //test on om:
    cv::Mat dom(3, 1, CV_64FC1);
    r.fill(dom, cv::RNG::NORMAL, 0, 1);
    dom *= 1e-9*cv::norm(om);
    cv::Mat om2 = om + dom;
    cv::fisheye::projectPoints(X, x2, om2, theT, theK, k, alpha, cv::noArray());
    xpred = x1 + cv::Mat(jacobians.colRange(8,11) * dom).reshape(2, 1);
    CV_Assert (cv::norm(x2 - xpred) < 1e-10);

    //test on f:
    cv::Mat df(2, 1, CV_64FC1);
    r.fill(df, cv::RNG::NORMAL, 0, 1);
    df *= 1e-9*cv::norm(f);
    cv::Matx33d K2 = theK + cv::Matx33d(df.at<double>(0), df.at<double>(0) * alpha, 0, 0, df.at<double>(1), 0, 0, 0, 0);
    cv::fisheye::projectPoints(X, x2, om, theT, K2, k, alpha, cv::noArray());
    xpred = x1 + cv::Mat(jacobians.colRange(0,2) * df).reshape(2, 1);
    CV_Assert (cv::norm(x2 - xpred) < 1e-10);

    //test on c:
    cv::Mat dc(2, 1, CV_64FC1);
    r.fill(dc, cv::RNG::NORMAL, 0, 1);
    dc *= 1e-9*cv::norm(c);
    K2 = theK + cv::Matx33d(0, 0, dc.at<double>(0), 0, 0, dc.at<double>(1), 0, 0, 0);
    cv::fisheye::projectPoints(X, x2, om, theT, K2, k, alpha, cv::noArray());
    xpred = x1 + cv::Mat(jacobians.colRange(2,4) * dc).reshape(2, 1);
    CV_Assert (cv::norm(x2 - xpred) < 1e-10);

    //test on k:
    cv::Mat dk(4, 1, CV_64FC1);
    r.fill(dk, cv::RNG::NORMAL, 0, 1);
    dk *= 1e-9*cv::norm(k);
    cv::Mat k2 = k + dk;
    cv::fisheye::projectPoints(X, x2, om, theT, theK, k2, alpha, cv::noArray());
    xpred = x1 + cv::Mat(jacobians.colRange(4,8) * dk).reshape(2, 1);
    CV_Assert (cv::norm(x2 - xpred) < 1e-10);

    //test on alpha:
    cv::Mat dalpha(1, 1, CV_64FC1);
    r.fill(dalpha, cv::RNG::NORMAL, 0, 1);
    dalpha *= 1e-9*cv::norm(f);
    double alpha2 = alpha + dalpha.at<double>(0);
    K2 = theK + cv::Matx33d(0, f.at<double>(0) * dalpha.at<double>(0), 0, 0, 0, 0, 0, 0, 0);
    cv::fisheye::projectPoints(X, x2, om, theT, theK, k, alpha2, cv::noArray());
    xpred = x1 + cv::Mat(jacobians.col(14) * dalpha).reshape(2, 1);
    CV_Assert (cv::norm(x2 - xpred) < 1e-10);
}

}}