faceMorph.cpp

#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
#include <fstream>
#include <iomanip>
#include <stdlib.h>

using namespace cv;
using namespace std;


// Read points stored in the text files
vector<Point2f> readPoints(string pointsFileName)
{
    vector<Point2f> points;
    ifstream ifs(pointsFileName);
    float x, y;
    while(ifs >> x >> y)
    {
        points.push_back(Point2f(x,y));
    }
    
    return points;
}

// Apply affine transform calculated using srcTri and dstTri to src
void applyAffineTransform(Mat &warpImage, Mat &src, vector<Point2f> &srcTri, vector<Point2f> &dstTri)
{
    
    // Given a pair of triangles, find the affine transform.
    Mat warpMat = getAffineTransform( srcTri, dstTri );
    
    // Apply the Affine Transform just found to the src image
    warpAffine( src, warpImage, warpMat, warpImage.size(), INTER_LINEAR, BORDER_REFLECT_101);
}

// Warps and alpha blends triangular regions from img1 and img2 to img
void morphTriangle(Mat &img1, Mat &img2, Mat &img, vector<Point2f> &t1, vector<Point2f> &t2, vector<Point2f> &t, double alpha)
{
    
    // Find bounding rectangle for each triangle
    Rect r = boundingRect(t);
    Rect r1 = boundingRect(t1);
    Rect r2 = boundingRect(t2);
    
    // Offset points by left top corner of the respective rectangles
    vector<Point2f> t1Rect, t2Rect, tRect;
    vector<Point> tRectInt;
    for(int i = 0; i < 3; i++)
    {
        tRect.push_back( Point2f( t[i].x - r.x, t[i].y -  r.y) );
        tRectInt.push_back( Point(t[i].x - r.x, t[i].y - r.y) ); // for fillConvexPoly
        
        t1Rect.push_back( Point2f( t1[i].x - r1.x, t1[i].y -  r1.y) );
        t2Rect.push_back( Point2f( t2[i].x - r2.x, t2[i].y - r2.y) );
    }
    
    // Get mask by filling triangle
    Mat mask = Mat::zeros(r.height, r.width, CV_32FC3);
    fillConvexPoly(mask, tRectInt, Scalar(1.0, 1.0, 1.0), 16, 0);
    
    // Apply warpImage to small rectangular patches
    Mat img1Rect, img2Rect;
    img1(r1).copyTo(img1Rect);
    img2(r2).copyTo(img2Rect);
    
    Mat warpImage1 = Mat::zeros(r.height, r.width, img1Rect.type());
    Mat warpImage2 = Mat::zeros(r.height, r.width, img2Rect.type());
    
    applyAffineTransform(warpImage1, img1Rect, t1Rect, tRect);
    applyAffineTransform(warpImage2, img2Rect, t2Rect, tRect);
    
    // Alpha blend rectangular patches
    Mat imgRect = (1.0 - alpha) * warpImage1 + alpha * warpImage2;
    
    // Copy triangular region of the rectangular patch to the output image
    multiply(imgRect,mask, imgRect);
    multiply(img(r), Scalar(1.0,1.0,1.0) - mask, img(r));
    img(r) = img(r) + imgRect;
    
    
}

int main( int argc, char** argv)
{
    
    string filename1("hillary_clinton.jpg");
    string filename2("ted_cruz.jpg");
    
    //alpha controls the degree of morph
    double alpha = 0.5;
    
    //Read input images
    Mat img1 = imread(filename1);
    Mat img2 = imread(filename2);
    
    //convert Mat to float data type
    img1.convertTo(img1, CV_32F);
    img2.convertTo(img2, CV_32F);
    
    
    //empty average image
    Mat imgMorph = Mat::zeros(img1.size(), CV_32FC3);
    
    
    //Read points
    vector<Point2f> points1 = readPoints( filename1 + ".txt");
    vector<Point2f> points2 = readPoints( filename2 + ".txt");
    vector<Point2f> points;
    
    //compute weighted average point coordinates
    for(int i = 0; i < points1.size(); i++)
    {
        float x, y;
        x = (1 - alpha) * points1[i].x + alpha * points2[i].x;
        y =  ( 1 - alpha ) * points1[i].y + alpha * points2[i].y;
        
        points.push_back(Point2f(x,y));
        
    }
    
    
    //Read triangle indices
    ifstream ifs("tri.txt");
    int x,y,z;
    
    while(ifs >> x >> y >> z)
    {
        // Triangles
        vector<Point2f> t1, t2, t;
        
        // Triangle corners for image 1.
        t1.push_back( points1[x] );
        t1.push_back( points1[y] );
        t1.push_back( points1[z] );
        
        // Triangle corners for image 2.
        t2.push_back( points2[x] );
        t2.push_back( points2[y] );
        t2.push_back( points2[z] );
        
        // Triangle corners for morphed image.
        t.push_back( points[x] );
        t.push_back( points[y] );
        t.push_back( points[z] );
        
        morphTriangle(img1, img2, imgMorph, t1, t2, t, alpha);
        
    }
    
    // Display Result
    imshow("Morphed Face", imgMorph / 255.0);
    waitKey(0);
    
    return 0;
}