opencv/modules/imgproc/test/test_drawing.cpp

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#include "test_precomp.hpp"

namespace opencv_test { namespace {

//#define DRAW_TEST_IMAGE

class CV_DrawingTest : public cvtest::BaseTest
{
public:
    CV_DrawingTest(){}
protected:
    void run( int );
    virtual void draw( Mat& img ) = 0;
    virtual int checkLineIterator( Mat& img) = 0;
    virtual int checkLineVirtualIterator() = 0;
};

void CV_DrawingTest::run( int )
{
    Mat testImg, valImg;
    const string fname = "../highgui/drawing/image.png";
    string path = ts->get_data_path(), filename;
    filename = path + fname;

    draw( testImg );

    valImg = imread( filename );
    if( valImg.empty() )
    {
        //imwrite( filename, testImg );
        ts->printf( ts->LOG, "test image can not be read");
#if defined(HAVE_PNG) || defined(HAVE_SPNG)
        ts->set_failed_test_info(cvtest::TS::FAIL_INVALID_TEST_DATA);
#else
        ts->printf( ts->LOG, "PNG image support is not available");
        ts->set_failed_test_info(cvtest::TS::OK);
#endif
        return;
    }
    else
    {
        // image should match exactly
        float err = (float)cvtest::norm( testImg, valImg, NORM_L1 );
        float Eps = 10;
        if( err > Eps)
        {
            //imshow("reference", valImg);
            //imshow("result", testImg);
            //waitKey();
            ts->printf( ts->LOG, "NORM_L1 between testImg and valImg is equal %f (larger than %f)\n", err, Eps );
            ts->set_failed_test_info(cvtest::TS::FAIL_BAD_ACCURACY);
        }
        else
        {
            ts->set_failed_test_info(checkLineIterator( testImg ));
        }
    }
    ts->set_failed_test_info(checkLineVirtualIterator());
    ts->set_failed_test_info(cvtest::TS::OK);
}

class CV_DrawingTest_CPP : public CV_DrawingTest
{
public:
    CV_DrawingTest_CPP() {}
protected:
    virtual void draw( Mat& img );
    virtual int checkLineIterator( Mat& img);
    virtual int checkLineVirtualIterator();
};

void CV_DrawingTest_CPP::draw( Mat& img )
{
    Size imgSize( 600, 400 );
    img.create( imgSize, CV_8UC3 );

    vector<Point> polyline(4);
    polyline[0] = Point(0, 0);
    polyline[1] = Point(imgSize.width, 0);
    polyline[2] = Point(imgSize.width, imgSize.height);
    polyline[3] = Point(0, imgSize.height);
    const Point* pts = &polyline[0];
    int n = (int)polyline.size();
    fillPoly( img, &pts, &n, 1, Scalar::all(255) );

    Point p1(1,1), p2(3,3);
    if( clipLine(Rect(0,0,imgSize.width,imgSize.height), p1, p2) && clipLine(imgSize, p1, p2) )
        circle( img, Point(300,100), 40, Scalar(0,0,255), 3 ); // draw

    p2 = Point(3,imgSize.height+1000);
    if( clipLine(Rect(0,0,imgSize.width,imgSize.height), p1, p2) && clipLine(imgSize, p1, p2) )
        circle( img, Point(500,300), 50, Scalar(255, 0, 0), 5, 8, 1 ); // draw

    p1 = Point(imgSize.width,1), p2 = Point(imgSize.width,3);
    if( clipLine(Rect(0,0,imgSize.width,imgSize.height), p1, p2) && clipLine(imgSize, p1, p2) )
        circle( img, Point(390,100), 10, Scalar(0,0,255), 3 ); // not draw

    p1 = Point(imgSize.width-1,1), p2 = Point(imgSize.width,3);
    if( clipLine(Rect(0,0,imgSize.width,imgSize.height), p1, p2) && clipLine(imgSize, p1, p2) )
        ellipse( img, Point(390,100), Size(20,30), 60, 0, 220.0, Scalar(0,200,0), 4 ); //draw

    ellipse( img, RotatedRect(Point(100,200),Size(200,100),160), Scalar(200,200,255), 5 );

    polyline.clear();
    ellipse2Poly( Point(430,180), Size(100,150), 30, 0, 150, 20, polyline );
    pts = &polyline[0];
    n = (int)polyline.size();
    polylines( img, &pts, &n, 1, false, Scalar(0,0,150), 4, cv::LINE_AA );
    n = 0;
    for( vector<Point>::const_iterator it = polyline.begin(); n < (int)polyline.size()-1; ++it, n++ )
    {
        line( img, *it, *(it+1), Scalar(50,250,100));
    }

    polyline.clear();
    ellipse2Poly( Point(500,300), Size(50,80), 0, 0, 180, 10, polyline );
    pts = &polyline[0];
    n = (int)polyline.size();
    polylines( img, &pts, &n, 1, true, Scalar(100,200,100), 20 );
    fillConvexPoly( img, pts, n, Scalar(0, 80, 0) );

    polyline.resize(8);
    // external rectengular
    polyline[0] = Point(0, 0);
    polyline[1] = Point(80, 0);
    polyline[2] = Point(80, 80);
    polyline[3] = Point(0, 80);
    // internal rectangular
    polyline[4] = Point(20, 20);
    polyline[5] = Point(60, 20);
    polyline[6] = Point(60, 60);
    polyline[7] = Point(20, 60);
    const Point* ppts[] = {&polyline[0], &polyline[0]+4};
    int pn[] = {4, 4};
    fillPoly( img, ppts, pn, 2, Scalar(100, 100, 0), 8, 0, Point(500, 20) );

    rectangle( img, Point(0, 300), Point(50, 398), Scalar(0,0,255) );

    string text1 = "OpenCV";
    int baseline = 0, thickness = 3, fontFace = FONT_HERSHEY_SCRIPT_SIMPLEX;
    float fontScale = 2;
    Size textSize = getTextSize( text1, fontFace, fontScale, thickness, &baseline);
    baseline += thickness;
    Point textOrg((img.cols - textSize.width)/2, (img.rows + textSize.height)/2);
    rectangle(img, textOrg + Point(0, baseline), textOrg + Point(textSize.width, -textSize.height), Scalar(0,0,255));
    line(img, textOrg + Point(0, thickness), textOrg + Point(textSize.width, thickness), Scalar(0, 0, 255));
    putText(img, text1, textOrg, fontFace, fontScale, Scalar(150,0,150), thickness, 8);

    string text2 = "abcdefghijklmnopqrstuvwxyz1234567890";
    Scalar color(200,0,0);
    fontScale = 0.5, thickness = 1;
    int dist = 5;

    textSize = getTextSize( text2, FONT_HERSHEY_SIMPLEX, fontScale, thickness, &baseline);
    textOrg = Point(5,5)+Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_SIMPLEX, fontScale, color, thickness, cv::LINE_AA);

    fontScale = 1;
    textSize = getTextSize( text2, FONT_HERSHEY_PLAIN, fontScale, thickness, &baseline);
    textOrg += Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_PLAIN, fontScale, color, thickness, cv::LINE_AA);

    fontScale = 0.5;
    textSize = getTextSize( text2, FONT_HERSHEY_DUPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_DUPLEX, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize( text2, FONT_HERSHEY_COMPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_COMPLEX, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize( text2, FONT_HERSHEY_TRIPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_TRIPLEX, fontScale, color, thickness, cv::LINE_AA);

    fontScale = 1;
    textSize = getTextSize( text2, FONT_HERSHEY_COMPLEX_SMALL, fontScale, thickness, &baseline);
    textOrg += Point(0,180) + Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_COMPLEX_SMALL, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize( text2, FONT_HERSHEY_SCRIPT_SIMPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_SCRIPT_SIMPLEX, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize( text2, FONT_HERSHEY_SCRIPT_COMPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_HERSHEY_SCRIPT_COMPLEX, fontScale, color, thickness, cv::LINE_AA);

    dist = 15, fontScale = 0.5;
    textSize = getTextSize( text2, FONT_ITALIC, fontScale, thickness, &baseline);
    textOrg += Point(0,textSize.height+dist);
    putText(img, text2, textOrg, FONT_ITALIC, fontScale, color, thickness, cv::LINE_AA);
}

int CV_DrawingTest_CPP::checkLineIterator( Mat& img )
{
    LineIterator it( img, Point(0,300), Point(1000, 300) );
    for(int i = 0; i < it.count; ++it, i++ )
    {
        Vec3b v = (Vec3b)(*(*it)) - img.at<Vec3b>(300,i);
        float err = (float)cvtest::norm( v, NORM_L2 );
        if( err != 0 )
        {
            ts->printf( ts->LOG, "LineIterator works incorrect" );
            ts->set_failed_test_info(cvtest::TS::FAIL_INVALID_OUTPUT);
        }
    }
    ts->set_failed_test_info(cvtest::TS::OK);
    return 0;
}

int CV_DrawingTest_CPP::checkLineVirtualIterator(  )
{
    RNG randomGenerator(1);
    for (size_t test = 0; test < 10000; ++test)
    {
        int width = randomGenerator.uniform(0, 512+1);
        int height = randomGenerator.uniform(0, 512+1);
        int x1 = randomGenerator.uniform(-512, 1024+1);
        int y1 = randomGenerator.uniform(-512, 1024+1);
        int x2 = randomGenerator.uniform(-512, 1024+1);
        int y2 = randomGenerator.uniform(-512, 1024+1);
        int x3 = randomGenerator.uniform(-512, 1024+1);
        int y3 = randomGenerator.uniform(-512, 1024+1);
        int channels = randomGenerator.uniform(1, 3+1);
        Mat m(cv::Size(width, height), CV_MAKETYPE(8U, channels));
        Point p1(x1, y1);
        Point p2(x2, y2);
        Point offset(x3, y3);
        LineIterator it( m, p1, p2 );
        LineIterator vit(Rect(offset.x, offset.y, width, height), p1 + offset, p2 + offset);
        if (it.count != vit.count)
        {
           ts->printf( ts->LOG, "virtual LineIterator works incorrectly" );
           ts->set_failed_test_info(cvtest::TS::FAIL_INVALID_OUTPUT);
           break;
        }
        else
        {
            for(int i = 0; i < it.count; ++it, ++vit, i++ )
            {
                Point pIt = it.pos();
                Point pVit = vit.pos() - offset;
                if (pIt != pVit)
                {
                    ts->printf( ts->LOG, "virtual LineIterator works incorrectly" );
                    ts->set_failed_test_info(cvtest::TS::FAIL_INVALID_OUTPUT);
                    break;
                }
            }
        }
    }
    ts->set_failed_test_info(cvtest::TS::OK);
    return 0;
}

class CV_DrawingTest_Far : public CV_DrawingTest_CPP
{
public:
    CV_DrawingTest_Far() {}
protected:
    virtual void draw(Mat& img);
};

void CV_DrawingTest_Far::draw(Mat& img)
{
    Size imgSize(32768 + 600, 400);
    img.create(imgSize, CV_8UC3);

    vector<Point> polyline(4);
    polyline[0] = Point(32768 + 0, 0);
    polyline[1] = Point(imgSize.width, 0);
    polyline[2] = Point(imgSize.width, imgSize.height);
    polyline[3] = Point(32768 + 0, imgSize.height);
    const Point* pts = &polyline[0];
    int n = (int)polyline.size();
    fillPoly(img, &pts, &n, 1, Scalar::all(255));

    Point p1(32768 + 1, 1), p2(32768 + 3, 3);
    if (clipLine(Rect(32768 + 0, 0, imgSize.width, imgSize.height), p1, p2) && clipLine(imgSize, p1, p2))
        circle(img, Point(32768 + 300, 100), 40, Scalar(0, 0, 255), 3); // draw

    p2 = Point(32768 + 3, imgSize.height + 1000);
    if (clipLine(Rect(32768 + 0, 0, imgSize.width, imgSize.height), p1, p2) && clipLine(imgSize, p1, p2))
        circle(img, Point(65536 + 500, 300), 50, Scalar(255, 0, 0), 5, 8, 1); // draw

    p1 = Point(imgSize.width, 1), p2 = Point(imgSize.width, 3);
    if (clipLine(Rect(32768 + 0, 0, imgSize.width, imgSize.height), p1, p2) && clipLine(imgSize, p1, p2))
        circle(img, Point(32768 + 390, 100), 10, Scalar(0, 0, 255), 3); // not draw

    p1 = Point(imgSize.width - 1, 1), p2 = Point(imgSize.width, 3);
    if (clipLine(Rect(32768 + 0, 0, imgSize.width, imgSize.height), p1, p2) && clipLine(imgSize, p1, p2))
        ellipse(img, Point(32768 + 390, 100), Size(20, 30), 60, 0, 220.0, Scalar(0, 200, 0), 4); //draw

    ellipse(img, RotatedRect(Point(32768 + 100, 200), Size(200, 100), 160), Scalar(200, 200, 255), 5);

    polyline.clear();
    ellipse2Poly(Point(32768 + 430, 180), Size(100, 150), 30, 0, 150, 20, polyline);
    pts = &polyline[0];
    n = (int)polyline.size();
    polylines(img, &pts, &n, 1, false, Scalar(0, 0, 150), 4, cv::LINE_AA);
    n = 0;
    for (vector<Point>::const_iterator it = polyline.begin(); n < (int)polyline.size() - 1; ++it, n++)
    {
        line(img, *it, *(it + 1), Scalar(50, 250, 100));
    }

    polyline.clear();
    ellipse2Poly(Point(32768 + 500, 300), Size(50, 80), 0, 0, 180, 10, polyline);
    pts = &polyline[0];
    n = (int)polyline.size();
    polylines(img, &pts, &n, 1, true, Scalar(100, 200, 100), 20);
    fillConvexPoly(img, pts, n, Scalar(0, 80, 0));

    polyline.resize(8);
    // external rectengular
    polyline[0] = Point(32768 + 0, 0);
    polyline[1] = Point(32768 + 80, 0);
    polyline[2] = Point(32768 + 80, 80);
    polyline[3] = Point(32768 + 0, 80);
    // internal rectangular
    polyline[4] = Point(32768 + 20, 20);
    polyline[5] = Point(32768 + 60, 20);
    polyline[6] = Point(32768 + 60, 60);
    polyline[7] = Point(32768 + 20, 60);
    const Point* ppts[] = { &polyline[0], &polyline[0] + 4 };
    int pn[] = { 4, 4 };
    fillPoly(img, ppts, pn, 2, Scalar(100, 100, 0), 8, 0, Point(500, 20));

    rectangle(img, Point(32768 + 0, 300), Point(32768 + 50, 398), Scalar(0, 0, 255));

    string text1 = "OpenCV";
    int baseline = 0, thickness = 3, fontFace = FONT_HERSHEY_SCRIPT_SIMPLEX;
    float fontScale = 2;
    Size textSize = getTextSize(text1, fontFace, fontScale, thickness, &baseline);
    baseline += thickness;
    Point textOrg((32768 + img.cols - textSize.width) / 2, (img.rows + textSize.height) / 2);
    rectangle(img, textOrg + Point(0, baseline), textOrg + Point(textSize.width, -textSize.height), Scalar(0, 0, 255));
    line(img, textOrg + Point(0, thickness), textOrg + Point(textSize.width, thickness), Scalar(0, 0, 255));
    putText(img, text1, textOrg, fontFace, fontScale, Scalar(150, 0, 150), thickness, 8);

    string text2 = "abcdefghijklmnopqrstuvwxyz1234567890";
    Scalar color(200, 0, 0);
    fontScale = 0.5, thickness = 1;
    int dist = 5;

    textSize = getTextSize(text2, FONT_HERSHEY_SIMPLEX, fontScale, thickness, &baseline);
    textOrg = Point(32768 + 5, 5) + Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_SIMPLEX, fontScale, color, thickness, cv::LINE_AA);

    fontScale = 1;
    textSize = getTextSize(text2, FONT_HERSHEY_PLAIN, fontScale, thickness, &baseline);
    textOrg += Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_PLAIN, fontScale, color, thickness, cv::LINE_AA);

    fontScale = 0.5;
    textSize = getTextSize(text2, FONT_HERSHEY_DUPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_DUPLEX, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize(text2, FONT_HERSHEY_COMPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_COMPLEX, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize(text2, FONT_HERSHEY_TRIPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_TRIPLEX, fontScale, color, thickness, cv::LINE_AA);

    fontScale = 1;
    textSize = getTextSize(text2, FONT_HERSHEY_COMPLEX_SMALL, fontScale, thickness, &baseline);
    textOrg += Point(0, 180) + Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_COMPLEX_SMALL, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize(text2, FONT_HERSHEY_SCRIPT_SIMPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_SCRIPT_SIMPLEX, fontScale, color, thickness, cv::LINE_AA);

    textSize = getTextSize(text2, FONT_HERSHEY_SCRIPT_COMPLEX, fontScale, thickness, &baseline);
    textOrg += Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_HERSHEY_SCRIPT_COMPLEX, fontScale, color, thickness, cv::LINE_AA);

    dist = 15, fontScale = 0.5;
    textSize = getTextSize(text2, FONT_ITALIC, fontScale, thickness, &baseline);
    textOrg += Point(0, textSize.height + dist);
    putText(img, text2, textOrg, FONT_ITALIC, fontScale, color, thickness, cv::LINE_AA);

    img = img(Rect(32768, 0, 600, 400)).clone();
}

TEST(Drawing,    cpp_regression) { CV_DrawingTest_CPP test; test.safe_run(); }
TEST(Drawing,    far_regression) { CV_DrawingTest_Far test; test.safe_run(); }

class CV_FillConvexPolyTest : public cvtest::BaseTest
{
public:
    CV_FillConvexPolyTest() {}
    ~CV_FillConvexPolyTest() {}
protected:
    void run(int)
    {
        vector<Point> line1;
        vector<Point> line2;

        line1.push_back(Point(1, 1));
        line1.push_back(Point(5, 1));
        line1.push_back(Point(5, 8));
        line1.push_back(Point(1, 8));

        line2.push_back(Point(2, 2));
        line2.push_back(Point(10, 2));
        line2.push_back(Point(10, 16));
        line2.push_back(Point(2, 16));

        Mat gray0(10,10,CV_8U, Scalar(0));
        fillConvexPoly(gray0, line1, Scalar(255), 8, 0);
        int nz1 = countNonZero(gray0);

        fillConvexPoly(gray0, line2, Scalar(0), 8, 1);
        int nz2 = countNonZero(gray0)/255;

        CV_Assert( nz1 == 40 && nz2 == 0 );
    }
};

TEST(Drawing, fillconvexpoly_clipping) { CV_FillConvexPolyTest test; test.safe_run(); }

class CV_DrawingTest_UTF8 : public cvtest::BaseTest
{
public:
    CV_DrawingTest_UTF8() {}
    ~CV_DrawingTest_UTF8() {}
protected:
    void run(int)
    {
        vector<string> lines;
        lines.push_back("abcdefghijklmnopqrstuvwxyz1234567890");
        // cyrillic letters small
        lines.push_back("\xD0\xB0\xD0\xB1\xD0\xB2\xD0\xB3\xD0\xB4\xD0\xB5\xD1\x91\xD0\xB6\xD0\xB7"
                        "\xD0\xB8\xD0\xB9\xD0\xBA\xD0\xBB\xD0\xBC\xD0\xBD\xD0\xBE\xD0\xBF\xD1\x80"
                        "\xD1\x81\xD1\x82\xD1\x83\xD1\x84\xD1\x85\xD1\x86\xD1\x87\xD1\x88\xD1\x89"
                        "\xD1\x8A\xD1\x8B\xD1\x8C\xD1\x8D\xD1\x8E\xD1\x8F");
        // cyrillic letters capital
        lines.push_back("\xD0\x90\xD0\x91\xD0\x92\xD0\x93\xD0\x94\xD0\x95\xD0\x81\xD0\x96\xD0\x97"
                        "\xD0\x98\xD0\x99\xD0\x9A\xD0\x9B\xD0\x9C\xD0\x9D\xD0\x9E\xD0\x9F\xD0\xA0"
                        "\xD0\xA1\xD0\xA2\xD0\xA3\xD0\xA4\xD0\xA5\xD0\xA6\xD0\xA7\xD0\xA8\xD0\xA9"
                        "\xD0\xAA\xD0\xAB\xD0\xAC\xD0\xAD\xD0\xAE\xD0\xAF");
        // bounds
        lines.push_back("-\xD0\x80-\xD0\x8E-\xD0\x8F-");
        lines.push_back("-\xD1\x90-\xD1\x91-\xD1\xBF-");
        // bad utf8
        lines.push_back("-\x81-\x82-\x83-");
        lines.push_back("--\xF0--");
        lines.push_back("-\xF0");

        vector<int> fonts;
        fonts.push_back(FONT_HERSHEY_SIMPLEX);
        fonts.push_back(FONT_HERSHEY_PLAIN);
        fonts.push_back(FONT_HERSHEY_DUPLEX);
        fonts.push_back(FONT_HERSHEY_COMPLEX);
        fonts.push_back(FONT_HERSHEY_TRIPLEX);
        fonts.push_back(FONT_HERSHEY_COMPLEX_SMALL);
        fonts.push_back(FONT_HERSHEY_SCRIPT_SIMPLEX);
        fonts.push_back(FONT_HERSHEY_SCRIPT_COMPLEX);

        vector<Mat> results;
        Size bigSize(0, 0);
        for (vector<int>::const_iterator font = fonts.begin(); font != fonts.end(); ++font)
        {
            for (int italic = 0; italic <= FONT_ITALIC; italic += FONT_ITALIC)
            {
                for (vector<string>::const_iterator line = lines.begin(); line != lines.end(); ++line)
                {
                    const float fontScale = 1;
                    const int thickness = 1;
                    const Scalar color(20,20,20);
                    int baseline = 0;

                    Size textSize = getTextSize(*line, *font | italic, fontScale, thickness, &baseline);
                    Point textOrg(0, textSize.height + 2);
                    Mat img(textSize + Size(0, baseline), CV_8UC3, Scalar(255, 255, 255));
                    putText(img, *line, textOrg, *font | italic, fontScale, color, thickness, cv::LINE_AA);

                    results.push_back(img);
                    bigSize.width = max(bigSize.width, img.size().width);
                    bigSize.height += img.size().height + 1;
                }
            }
        }

        int shift = 0;
        Mat result(bigSize, CV_8UC3, Scalar(100, 100, 100));
        for (vector<Mat>::const_iterator img = results.begin(); img != results.end(); ++img)
        {
            Rect roi(Point(0, shift), img->size());
            Mat sub(result, roi);
            img->copyTo(sub);
            shift += img->size().height + 1;
        }
        if (cvtest::debugLevel > 0)
            imwrite("all_fonts.png", result);
    }
};

TEST(Drawing, utf8_support) { CV_DrawingTest_UTF8 test; test.safe_run(); }


TEST(Drawing, _914)
{
    const int rows = 256;
    const int cols = 256;

    Mat img(rows, cols, CV_8UC1, Scalar(255));

    line(img, Point(0, 10), Point(255, 10), Scalar(0), 2, 4);
    line(img, Point(-5, 20), Point(260, 20), Scalar(0), 2, 4);
    line(img, Point(10, 0), Point(10, 255), Scalar(0), 2, 4);

    double x0 = 0.0/pow(2.0, -2.0);
    double x1 = 255.0/pow(2.0, -2.0);
    double y = 30.5/pow(2.0, -2.0);

    line(img, Point(int(x0), int(y)), Point(int(x1), int(y)), Scalar(0), 2, 4, 2);

    int pixelsDrawn = rows*cols - countNonZero(img);
    ASSERT_EQ( (3*rows + cols)*3 - 3*9, pixelsDrawn);
}

TEST(Drawing, polylines_empty)
{
    Mat img(100, 100, CV_8UC1, Scalar(0));
    vector<Point> pts; // empty
    polylines(img, pts, false, Scalar(255));
    int cnt = countNonZero(img);
    ASSERT_EQ(cnt, 0);
}

TEST(Drawing, polylines)
{
    Mat img(100, 100, CV_8UC1, Scalar(0));
    vector<Point> pts;
    pts.push_back(Point(0, 0));
    pts.push_back(Point(20, 0));
    polylines(img, pts, false, Scalar(255));
    int cnt = countNonZero(img);
    ASSERT_EQ(cnt, 21);
}

TEST(Drawing, longline)
{
    Mat mat = Mat::zeros(256, 256, CV_8UC1);

    line(mat, cv::Point(34, 204), cv::Point(46400, 47400), cv::Scalar(255), 3);
    EXPECT_EQ(310, cv::countNonZero(mat));

    Point pt[6];
    pt[0].x = 32;
    pt[0].y = 204;
    pt[1].x = 34;
    pt[1].y = 202;
    pt[2].x = 87;
    pt[2].y = 255;
    pt[3].x = 82;
    pt[3].y = 255;
    pt[4].x = 37;
    pt[4].y = 210;
    pt[5].x = 37;
    pt[5].y = 209;
    fillConvexPoly(mat, pt, 6, cv::Scalar(0));

    EXPECT_EQ(0, cv::countNonZero(mat));
}


TEST(Drawing, putText_no_garbage)
{
    Size sz(640, 480);
    Mat mat = Mat::zeros(sz, CV_8UC1);

    mat = Scalar::all(0);
    putText(mat, "029", Point(10, 350), 0, 10, Scalar(128), 15);

    EXPECT_EQ(0, cv::countNonZero(mat(Rect(0, 0,           10, sz.height))));
    EXPECT_EQ(0, cv::countNonZero(mat(Rect(sz.width-10, 0, 10, sz.height))));
    EXPECT_EQ(0, cv::countNonZero(mat(Rect(190, 0,         10, sz.height))));
    EXPECT_EQ(0, cv::countNonZero(mat(Rect(380, 0,         10, sz.height))));

#if 0
    rectangle(mat, Rect(0, 0,           10, sz.height), Scalar::all(255), 1, LINE_8);
    rectangle(mat, Rect(sz.width-10, 0, 10, sz.height), Scalar::all(255), 1, LINE_8);
    rectangle(mat, Rect(190, 0,         10, sz.height), Scalar::all(255), 1, LINE_8);
    rectangle(mat, Rect(380, 0,         10, sz.height), Scalar::all(255), 1, LINE_8);
    imshow("result", mat);
    waitKey();
#endif
}


TEST(Drawing, line)
{
    Mat mat = Mat::zeros(Size(100,100), CV_8UC1);

    ASSERT_THROW(line(mat, Point(1,1),Point(99,99),Scalar(255),0), cv::Exception);
}

TEST(Drawing, regression_16308)
{
    Mat_<uchar> img(Size(100, 100), (uchar)0);
    circle(img, Point(50, 50), 50, 255, 1, LINE_AA);
    EXPECT_NE(0, (int)img.at<uchar>(0, 50));
    EXPECT_NE(0, (int)img.at<uchar>(50, 0));
    EXPECT_NE(0, (int)img.at<uchar>(50, 99));
    EXPECT_NE(0, (int)img.at<uchar>(99, 50));
}

TEST(Drawing, fillpoly_circle)
{
    Mat img_c(640, 480, CV_8UC3, Scalar::all(0));
    Mat img_fp = img_c.clone(), img_fcp = img_c.clone(), img_fp3 = img_c.clone();

    Point center1(img_c.cols/2, img_c.rows/2);
    Point center2(img_c.cols/10, img_c.rows*3/4);
    Point center3 = Point(img_c.cols, img_c.rows) - center2;
    int radius = img_c.rows/4;
    int radius_small = img_c.cols/15;
    Scalar color(0, 0, 255);

    circle(img_c, center1, radius, color, -1);

    // check that circle, fillConvexPoly and fillPoly
    // give almost the same result then asked to draw a single circle
    vector<Point> vtx;
    ellipse2Poly(center1, Size(radius, radius), 0, 0, 360, 1, vtx);
    fillConvexPoly(img_fcp, vtx, color);
    fillPoly(img_fp, vtx, color);
    double diff_fp = cv::norm(img_c, img_fp, NORM_L1)/(255*radius*2*CV_PI);
    double diff_fcp = cv::norm(img_c, img_fcp, NORM_L1)/(255*radius*2*CV_PI);
    EXPECT_LT(diff_fp, 1.);
    EXPECT_LT(diff_fcp, 1.);

    // check that fillPoly can draw 3 disjoint circles at once
    circle(img_c, center2, radius_small, color, -1);
    circle(img_c, center3, radius_small, color, -1);

    vector<vector<Point> > vtx3(3);
    vtx3[0] = vtx;
    ellipse2Poly(center2, Size(radius_small, radius_small), 0, 0, 360, 1, vtx3[1]);
    ellipse2Poly(center3, Size(radius_small, radius_small), 0, 0, 360, 1, vtx3[2]);
    fillPoly(img_fp3, vtx3, color);
    double diff_fp3 = cv::norm(img_c, img_fp3, NORM_L1)/(255*(radius+radius_small*2)*2*CV_PI);
    EXPECT_LT(diff_fp3, 1.);
}


TEST(Drawing, fromJava_getTextSize)
{
    String text = "Android all the way";
    double fontScale = 2;
    int thickness = 3;
    int baseLine = 0;

    Size res0 = getTextSize(text, FONT_HERSHEY_SCRIPT_SIMPLEX, fontScale, thickness, 0);
    Size res = getTextSize(text, FONT_HERSHEY_SCRIPT_SIMPLEX, fontScale, thickness, &baseLine);

#if 0
    Mat img(200, 700, CV_8UC3, Scalar::all(255));
    Point org(100, 100);
    putText(img, text, org, FONT_HERSHEY_SCRIPT_SIMPLEX, fontScale, Scalar(128, 0, 0), thickness);
    rectangle(img, org, Point(org.x + res0.width, org.y - res0.height), Scalar(0, 0, 128), 2, LINE_AA);
    imshow("result", img);
    waitKey();
#endif

    EXPECT_EQ(res0.width, res.width);
    EXPECT_EQ(res0.height, res.height);
    EXPECT_NEAR(494, res.width, 3.0);
    EXPECT_NEAR(51, res.height, 3.0);
    EXPECT_NEAR(10, baseLine, 3.0);
}

TEST(Drawing, fromJava_testPutTextMatStringPointIntDoubleScalarIntIntBoolean)
{
    String text = "Hello World";
    Size labelSize(170, 23);

    Mat img(20 + (int)labelSize.height, 20 + (int)labelSize.width, CV_8U, Scalar::all(0));
    Point origin(10, 10);

    putText(img, text, origin, FONT_HERSHEY_SIMPLEX, 1.0, Scalar::all(255), 1, LINE_8, true);

    EXPECT_LT(0, countNonZero(img));
    // check that border is not corrupted
    rectangle(img, origin,
                Point(origin.x + labelSize.width, origin.y + labelSize.height),
                      Scalar::all(0), -1, 8);
    //imshow("img", img);
    //waitKey();
    EXPECT_EQ(0, countNonZero(img));

    origin = Point(10, labelSize.height + 10);

    putText(img, text, origin, FONT_HERSHEY_SIMPLEX, 1.0, Scalar::all(255));
    EXPECT_LT(0, countNonZero(img));
    // check that border is not corrupted
    rectangle(img, Point(10, 10), Point(labelSize.width + 10, labelSize.height + 10), Scalar::all(0), -1);
    EXPECT_EQ(0, countNonZero(img));
}

typedef struct TextProp
{
    const char* str;
    bool ralign;
    int weight;
    bool italic;
} TextProp;

#ifdef HAVE_UNIFONT // there are other tests for text drawing, so the functionality is tested anyway,
                    // but this test needs concrete unicode font to compare the printed text
                    // (including CJK characters) with the reference picture from the database
TEST(Drawing, ttf_text)
{
    string ts_data_path = TS::ptr()->get_data_path();
    string custom_font_path = ts_data_path + "../highgui/drawing/";

    FontFace sans("sans");
    FontFace italic("italic");
    Mat img(600, 1300, CV_8UC3);
    TextProp text[] =
    {
        {"The quick brown fox jumps over lazy dog. Fly, start, finish, shuffle shuttle.", false, 400, false},
        {"vechicle #5 detected; fps=123.45.\n", false, 600, false},
        {"Съешь же ещё этих мягких французских булок, да выпей чаю!\n"
        "Dès Noël où un zéphyr haï me vêt de glaçons würmiens je dîne\nd’exquis rôtis de bœuf au kir à l’aÿ d’âge mûr & cætera!\n"
        "“Falsches Üben von Xylophonmusik quält jeden größeren Zwerg”.", false, 400, true},

        {"¡Oh tú, sabio encantador, quienquiera que seas,\n"
         "a quien ha de tocar el ser coronista desta peregrina\n"
         "historia, ruégote que no te olvides de mi buen Rocinante,\n"
         "compañero eterno mío en todos mis caminos y carreras!\n", false, 300, false},
        {"Ταχίστη αλώπηξ βαφής ψημένη γη, δρασκελίζει υπέρ νωθρού κυνός.", false, 400, false},
        {"春眠不觉晓，\n处处闻啼鸟。\n夜来风雨声，\n花落知多少。\n"
        " あなたはそれが困難見つけた場合 — あなたは正しい方向に向かっている。\n"
        " 넌 모든 꽃들을 다 꺾어버릴 수는 있겠지만, 봄이 오는 걸 막을 수는 없어。 ", false, 400, false}
    };
    Scalar color(150, 80, 0);

    for(int iter = 0; iter < 1; iter++)
    {
        //double ts = (double)getTickCount();
        img.setTo(Scalar::all(255));
        int sz = 20;
        int x0 = 50, y0 = 70;
        Point org(x0, y0);

        int j = 0, column = 1;
        for(const TextProp& t: text)
        {
            PutTextFlags flags = t.ralign ? PUT_TEXT_ALIGN_RIGHT : PUT_TEXT_ALIGN_LEFT;
            if(t.ralign)
            {
                if(j > 0)
                    break;
                if(column == 1)
                {
                    column = 2;
                    org.y = y0;
                }
                org.x = img.cols - x0;
            }
            else
            {
                org.x = column == 1 ? x0 : img.cols/2;
            }
            FontFace& face = t.italic ? italic : sans;
            //Rect r = getTextSize(img.size(), t.str, org, face, sz, t.weight, flags);
            org = putText(img, t.str, org, color, face,
                          sz, t.weight, flags, Range());
            //rectangle(img, r, Scalar(80, 0, 128), 1, LINE_AA);
            org.y += sz + 10;
        }

        Scalar color2(80, 0, 128);

        org = Point(img.cols - 500, 150);
        putText(img, "Пробуем\n ", org, color2, italic, 80, 300,
                PUT_TEXT_ALIGN_LEFT, Range());
        org.x -= 90;
        org.y += 130;
        // testing alternative way to set the weight;
        // in putText we use weight=0
        italic.setInstance({CV_FOURCC('w','g','h','t'), 800<<16});
        putText(img, "OpenCV", org, color2, italic, 120, 0,
                PUT_TEXT_ALIGN_LEFT, Range());
        org.y += 140;
        org.x += 60;
        putText(img, "打印文字", org, color2, sans, 100, 400,
                PUT_TEXT_ALIGN_LEFT, Range());
        //ts = (double)getTickCount() - ts;
        //printf("iter=%d. ts=%.2fms\n", iter, ts*1000./getTickFrequency());
    }

#if 0
    //imwrite(ts_data_path + "../highgui/drawing/text_test.png", img);
    imshow("test", img);
    waitKey();
#else
    Mat refimg = imread(ts_data_path + "../highgui/drawing/text_test.png", IMREAD_UNCHANGED);
    //imshow("ref", refimg);
    //imshow("actual", img);
    //absdiff(refimg, img, refimg);
    //imshow("diff", refimg);
    //waitKey();
    EXPECT_EQ(refimg.size(), img.size());
    EXPECT_LT(cv::norm(refimg, img, NORM_L1), 6500);
#endif
}
#endif


TEST(Drawing, fillpoly_fully)
{
    unsigned imageWidth = 256;
    unsigned imageHeight = 256;
    int type = CV_8UC1;
    int shift = 0;
    Point offset(0, 0);
    cv::LineTypes lineType = LINE_4;

    int imageSizeOffset = 15;

    cv::Mat img(imageHeight, imageWidth, type);
    img = 0;

    std::vector<cv::Point> polygonPoints;
    polygonPoints.push_back(cv::Point(100, -50));
    polygonPoints.push_back(cv::Point(imageSizeOffset, imageHeight - imageSizeOffset));
    polygonPoints.push_back(cv::Point(imageSizeOffset, imageSizeOffset));

    // convert data
    std::vector<const cv::Point*> polygonPointPointers(polygonPoints.size());
    for (size_t i = 0; i < polygonPoints.size(); i++)
    {
        polygonPointPointers[i] = &polygonPoints[i];
    }

    const cv::Point** data = &polygonPointPointers.front();
    int size = (int)polygonPoints.size();
    const int* npts = &size;
    int ncontours = 1;

    // generate image
    cv::fillPoly(img, data, npts, ncontours, 255, lineType, shift, offset);

    // check for artifacts
    {
        cv::Mat binary = img < 128;
        cv::Mat labelImage(binary.size(), CV_32S);
        cv::Mat labelCentroids;
        int labels = cv::connectedComponents(binary, labelImage, 4);
        EXPECT_EQ(2, labels) << "artifacts occured";
    }

    // check if filling went over border
    {
        int xy_shift = 16, delta = offset.y + ((1 << shift) >> 1);
        int xy_one = 1 << xy_shift;

        Point pt0(polygonPoints[polygonPoints.size() - 1]), pt1;
        for (size_t i = 0; i < polygonPoints.size(); i++, pt0 = pt1)
        {
            pt1 = polygonPoints[i];

            // offset/shift treated like in fillPoly
            Point t0(pt0), t1(pt1);

            t0.x = (t0.x + offset.x) << (xy_shift - shift);
            t0.y = (t0.y + delta) >> shift;

            t1.x = (t1.x + offset.x) << (xy_shift - shift);
            t1.y = (t1.y + delta) >> shift;

            if (lineType < LINE_AA)
            {
                t0.x = (t0.x + (xy_one >> 1)) >> xy_shift;
                t1.x = (t1.x + (xy_one >> 1)) >> xy_shift;

                // LINE_4 to use the same type of line which is used in fillPoly
                line(img, t0, t1, 0, 1, LINE_4, 0);
            }
            else
            {
                t0.x >>= (xy_shift);
                t1.x >>= (xy_shift);
                line(img, t0, t1, 0, 1, lineType, 0);
            }

        }
        cv::Mat binary = img < 254;
        cv::Mat labelImage(binary.size(), CV_32S);
        int labels = cv::connectedComponents(binary, labelImage, 4);
        EXPECT_EQ(2, labels) << "filling went over the border";
    }
}

PARAM_TEST_CASE(FillPolyFully, unsigned, unsigned, int, int, Point, cv::LineTypes)
{
    unsigned imageWidth;
    unsigned imageHeight;
    int type;
    int shift;
    Point offset;
    cv::LineTypes lineType;

    virtual void SetUp()
    {
        imageWidth = GET_PARAM(0);
        imageHeight = GET_PARAM(1);
        type = GET_PARAM(2);
        shift = GET_PARAM(3);
        offset = GET_PARAM(4);
        lineType = GET_PARAM(5);
    }

    void draw_polygon(cv::Mat& img, const std::vector<cv::Point>& polygonPoints)
    {
        // convert data
        std::vector<const cv::Point*> polygonPointPointers(polygonPoints.size());
        for (size_t i = 0; i < polygonPoints.size(); i++)
        {
            polygonPointPointers[i] = &polygonPoints[i];
        }

        const cv::Point** data = &polygonPointPointers.front();
        int size = (int)polygonPoints.size();
        const int* npts = &size;
        int ncontours = 1;

        // generate image
        cv::fillPoly(img, data, npts, ncontours, 255, lineType, shift, offset);
    }

    void check_artifacts(cv::Mat& img)
    {
        // check for artifacts
        cv::Mat binary = img < 128;
        cv::Mat labelImage(binary.size(), CV_32S);
        cv::Mat labelCentroids;
        int labels = cv::connectedComponents(binary, labelImage, 4);
        EXPECT_EQ(2, labels) << "artifacts occured";
    }

    void check_filling_over_border(cv::Mat& img, const std::vector<cv::Point>& polygonPoints)
    {
        int xy_shift = 16, delta = offset.y + ((1 << shift) >> 1);
        int xy_one = 1 << xy_shift;

        Point pt0(polygonPoints[polygonPoints.size() - 1]), pt1;
        for (size_t i = 0; i < polygonPoints.size(); i++, pt0 = pt1)
        {
            pt1 = polygonPoints[i];

            // offset/shift treated like in fillPoly
            Point t0(pt0), t1(pt1);

            t0.x = (t0.x + offset.x) << (xy_shift - shift);
            t0.y = (t0.y + delta) >> shift;

            t1.x = (t1.x + offset.x) << (xy_shift - shift);
            t1.y = (t1.y + delta) >> shift;

            if (lineType < LINE_AA)
            {
                t0.x = (t0.x + (xy_one >> 1)) >> xy_shift;
                t1.x = (t1.x + (xy_one >> 1)) >> xy_shift;

                // LINE_4 to use the same type of line which is used in fillPoly
                line(img, t0, t1, 0, 1, LINE_4, 0);
            }
            else
            {
                t0.x >>= (xy_shift);
                t1.x >>= (xy_shift);
                line(img, t0, t1, 0, 1, lineType, 0);
            }

        }
        cv::Mat binary = img < 254;
        cv::Mat labelImage(binary.size(), CV_32S);
        int labels = cv::connectedComponents(binary, labelImage, 4);
        EXPECT_EQ(2, labels) << "filling went over the border";
    }

    void run_test(const std::vector<cv::Point>& polygonPoints)
    {
        cv::Mat img(imageHeight, imageWidth, type);
        img = 0;

        draw_polygon(img, polygonPoints);
        check_artifacts(img);
        check_filling_over_border(img, polygonPoints);
    }
};

TEST_P(FillPolyFully, DISABLED_fillpoly_fully)
{
    int imageSizeOffset = 15;

    // testing for polygon with straight edge at left/right side
    int positions1[2] = { imageSizeOffset, (int)imageWidth - imageSizeOffset };
    for (size_t i = 0; i < 2; i++)
    {
        for (int y = imageHeight + 50; y > -50; y -= 1)
        {
            // define polygon
            std::vector<cv::Point> polygonPoints;
            polygonPoints.push_back(cv::Point(100, imageHeight - y));
            polygonPoints.push_back(cv::Point(positions1[i], positions1[1]));
            polygonPoints.push_back(cv::Point(positions1[i], positions1[0]));

            run_test(polygonPoints);
        }
    }

    // testing for polygon with straight edge at top/bottom side
    int positions2[2] = { imageSizeOffset, (int)imageHeight - imageSizeOffset };
    for (size_t i = 0; i < 2; i++)
    {
        for (int x = imageWidth + 50; x > -50; x -= 1)
        {
            // define polygon
            std::vector<cv::Point> polygonPoints;
            polygonPoints.push_back(cv::Point(imageWidth - x, 100));
            polygonPoints.push_back(cv::Point(positions2[1], positions2[i]));
            polygonPoints.push_back(cv::Point(positions2[0], positions2[i]));

            run_test(polygonPoints);
        }
    }
}

INSTANTIATE_TEST_CASE_P(
    FillPolyTest, FillPolyFully,
    testing::Combine(
        testing::Values(256),
        testing::Values(256),
        testing::Values(CV_8UC1),
        testing::Values(0, 1, 2),
        testing::Values(cv::Point(0, 0), cv::Point(10, 10)),
        testing::Values(LINE_4, LINE_8, LINE_AA)
    )
);

TEST(Drawing, circle_overflow)
{
    applyTestTag(CV_TEST_TAG_VERYLONG);
    cv::Mat1b matrix = cv::Mat1b::zeros(600, 600);
    cv::Scalar kBlue = cv::Scalar(0, 0, 255);
    cv::circle(matrix, cv::Point(275, -2147483318), 2147483647, kBlue, 1, 8, 0);
}

TEST(Drawing, circle_memory_access)
{
    cv::Mat1b matrix = cv::Mat1b::zeros(10, 10);
    cv::Scalar kBlue = cv::Scalar(0, 0, 255);
    cv::circle(matrix, cv::Point(-1, -1), 0, kBlue, 2, 8, 16);
}

inline static Mat mosaic2x2(Mat &img)
{
    const Size sz = img.size();
    Mat res(sz * 2, img.type(), Scalar::all(0));
    img.copyTo(res(Rect(Point(0, 0), sz)));
    img.copyTo(res(Rect(Point(0, sz.height), sz)));
    img.copyTo(res(Rect(Point(sz.width, 0), sz)));
    img.copyTo(res(Rect(Point(sz.width, sz.height), sz)));
    return res;
}

TEST(Drawing, contours_filled)
{
    const Scalar white(255);
    const Scalar black(0);
    const Size sz(100, 100);

    Mat img(sz, CV_8UC1, black);
    rectangle(img, Point(20, 20), Point(80, 80), white, -1);
    rectangle(img, Point(30, 30), Point(70, 70), black, -1);
    rectangle(img, Point(40, 40), Point(60, 60), white, -1);
    img = mosaic2x2(img);

    Mat img1(sz, CV_8UC1, black);
    rectangle(img1, Point(20, 20), Point(80, 80), white, -1);
    img1 = mosaic2x2(img1);

    Mat img2(sz, CV_8UC1, black);
    rectangle(img2, Point(20, 20), Point(80, 80), white, -1);
    rectangle(img2, Point(30, 30), Point(70, 70), black, -1);
    img2 = mosaic2x2(img2);

    Mat img3(sz, CV_8UC1, black);
    rectangle(img3, Point(40, 40), Point(60, 60), white, -1);
    img3 = mosaic2x2(img3);

    // inverted contours - corners and left edge adjusted
    Mat imgi(sz, CV_8UC1, black);
    rectangle(imgi, Point(29, 29), Point(71, 71), white, -1);
    rectangle(imgi, Point(41, 41), Point(59, 59), black, -1);
    imgi.at<uchar>(Point(29, 29)) = 0;
    imgi.at<uchar>(Point(29, 71)) = 0;
    imgi = mosaic2x2(imgi);

    vector<vector<Point>> contours;
    vector<Vec4i> hierarchy;
    findContours(img, contours, hierarchy, RETR_TREE, CHAIN_APPROX_NONE);
    ASSERT_EQ(12u, contours.size());

    // NOTE:
    // assuming contour tree has following structure (idx = 0, 1, ...):
    //   idx (top level)
    //     - idx + 1
    //         - idx + 2
    //   idx + 3 (top level)
    //     - idx + 4
    //         - idx + 5
    //   ...
    const vector<int> top_contours {0, 3, 6, 9};
    {
        // all contours
        Mat res(img.size(), CV_8UC1, Scalar::all(0));
        drawContours(res, contours, -1, white, -1, cv::LINE_8, hierarchy);
        EXPECT_LT(cvtest::norm(img, res, NORM_INF), 1);
    }
    {
        // all contours
        Mat res(img.size(), CV_8UC1, Scalar::all(0));
        drawContours(res, contours, -1, white, -1, cv::LINE_8, hierarchy, 3);
        EXPECT_LT(cvtest::norm(img, res, NORM_INF), 1);
    }
    {
        // all contours
        Mat res(img.size(), CV_8UC1, Scalar::all(0));
        drawContours(res, contours, -1, white, -1, cv::LINE_8, hierarchy, 0);
        EXPECT_LT(cvtest::norm(img, res, NORM_INF), 1);
    }
    {
        // all external contours one by one
        Mat res(img.size(), CV_8UC1, Scalar::all(0));
        for (int idx : top_contours)
            drawContours(res, contours, idx, white, -1, cv::LINE_8, hierarchy, 0);
        EXPECT_LT(cvtest::norm(img1, res, NORM_INF), 1);
    }
    {
        // all external contours + 1-level deep hole (one by one)
        Mat res(img.size(), CV_8UC1, Scalar::all(0));
        for (int idx : top_contours)
            drawContours(res, contours, idx, white, -1, cv::LINE_8, hierarchy, 1);
        EXPECT_LT(cvtest::norm(img2, res, NORM_INF), 1);
    }
    {
        // 2-level deep contours
        Mat res(img.size(), CV_8UC1, Scalar::all(0));
        for (int idx : top_contours)
            drawContours(res, contours, idx + 2, white, -1, cv::LINE_8, hierarchy);
        EXPECT_LT(cvtest::norm(img3, res, NORM_INF), 1);
    }
    {
        // holes become inverted here, LINE_8 -> LINE_4
        Mat res(img.size(), CV_8UC1, Scalar::all(0));
        for (int idx : top_contours)
            drawContours(res, contours, idx + 1, white, -1, cv::LINE_4, hierarchy);
        EXPECT_LT(cvtest::norm(imgi, res, NORM_INF), 1);
    }
}

}} // namespace