12_affine_transform.cpp

//
// Created by varora on 22/04/24.
//
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/imgproc.hpp"
#include <iostream>

using namespace cv;
using namespace std;

int main( int argc, char** argv )
{
    CommandLineParser parser(argc, argv, "{@input | ims/sample.jpg | input image}");
    Mat src = imread( samples::findFile( parser.get<String>( "@input" ) ) );
    if( src.empty() )
    {
        cout << "Could not open or find the image./n" << endl;
        cout << "Usage: " << argv[0] << " <Input image>" << endl;
        return -1;
    }

    Point2f srcTri[3];
    srcTri[0] = Point2f( 0.f, 0.f );
    srcTri[1] = Point2f( src.cols - 1.f, 0.f );
    srcTri[2] = Point2f( 0.f, src.rows - 1.f );

    Point2f dstTri[3];
    dstTri[0] = Point2f( 0.f, src.rows*0.33f );
    dstTri[1] = Point2f( src.cols*0.85f, src.rows*0.25f );
    dstTri[2] = Point2f( src.cols*0.15f, src.rows*0.7f );

    Mat warp_mat = getAffineTransform( srcTri, dstTri );

    Mat warp_dst = Mat::zeros( src.rows, src.cols, src.type() );

    warpAffine(src, warp_dst, warp_mat, warp_dst.size() );

    Point center = Point( warp_dst.cols/2, warp_dst.rows/2 );
    double angle = -50.0;
    double scale = 0.6;

    Mat rot_mat = getRotationMatrix2D( center, angle, scale );

    Mat warp_rotate_dst;
    warpAffine( warp_dst, warp_rotate_dst, rot_mat, warp_dst.size() );

    imshow( "Source image", src );
    imshow( "Warp", warp_dst );
    imshow( "Warp + Rotate", warp_rotate_dst );

    waitKey();

    return 0;
}