simple_interp

#include "ofMain.h"
#include "ofxCv.h"

const string path_0 = "prev.tif";
const string path_1 = "cur.tif";

class ofApp : public ofBaseApp
{
    ofVideoGrabber video;
    ofxCv::FlowFarneback forward;
    ofxCv::FlowFarneback backward;
    
    ofImage prev, cur;
    ofImage interpolate;
    
    float amt = 0;
public:
    void setup()
    {
        ofSetFrameRate(60);
        ofSetVerticalSync(true);
        ofBackground(0);
        
        prev.loadImage(path_0);
        cur.loadImage(path_1);
        
        ofxCv::imitate(interpolate, cur, CV_8UC3);
        
        {
            forward.setPyramidScale(0.5);
            forward.setNumLevels(3);
            forward.setWindowSize(15);
            forward.setNumIterations(3);
            forward.setPolyN(5);
            forward.setPolySigma(1.2);
        }
    }
    
    int toIndex(int x, int y, int w, int ch) { return (y*w + x)*ch; }
    void update()
    {
        amt = ofMap(mouseX, 0, ofGetWidth(), 0, 1, true);
        
        forward.calcOpticalFlow(prev, cur);
        backward.calcOpticalFlow(cur, prev);
        
        int w = interpolate.width, h = interpolate.height;
        unsigned char* pix = interpolate.getPixels();
        unsigned char* prev_pix = prev.getPixels();
        unsigned char* cur_pix = cur.getPixels();
        for (int y=0; y<h; y++) {
            for (int x=0; x<w; x++) {
                const ofVec2f f = forward.getFlowOffset(x, y) * amt;
                const int from_i = toIndex(x, y, w, 3);
                const int to_i = toIndex(ofClamp(x+f.x, 0, w-1), ofClamp(y+f.y, 0, h-1), w, 3);
                pix[from_i]   = prev_pix[to_i];
                pix[from_i+1] = prev_pix[to_i+1];
                pix[from_i+2] = prev_pix[to_i+2];
            }
        }
        interpolate.update();
    }
    
    void draw()
    {
        prev.draw(0, 0);
        backward.draw();
        
        ofTranslate(640, 0);
        cur.draw(0, 0);
        forward.draw();
        
        interpolate.draw(0, 480);
    }
    
    void keyPressed(int key)
    {
    }
};

//========================================================================
int main( ) {
	ofSetupOpenGL(1280,480*2,OF_WINDOW);
	ofRunApp(new ofApp());
}