package association;

import hypothesis_validation.HoG_Score;

import java.awt.image.BufferedImage;
import java.util.ArrayList;
import tracking.TrackRegion;

public class Probabilities {
	
	
    /* Probability that a detected sub-image {v2} in the current frame is the same
    text object as a sub-image {v0} in the previous frame. */
        
        public double prob_a 
            ( BufferedImage V0, /* Sub-image in previous frame. */
              BufferedImage V2, /* Detected sub-image in current frame. */
              double sigma, 
              ArrayList<String> HPAR )
	{
		HoG_Score score = new HoG_Score();
		
		double[] e0 = score.get_descriptor (false, V0, HPAR);
		double[] e2 = score.get_descriptor (false, V2, HPAR);
                
                double dist2 = 0;
                for (int i = 0; i < e0.length; i++) {
                    double d = e0[i] - e2[i];
                    dist2 += d*d;
		}
                obs.normalize_histogram(histo2);

		return Math.exp (-0.5*dist2/(sigma*sigma));
	}
	
	public double prob_p (TrackRegion A1, TrackRegion A2, double sigma)
	{
            double dx = A2.get_Cx() - A1.get_Cx();
            double dy = A2.get_Cy() - A1.get_Cy();
            double d2 = dx*dx + dy*dy;
	    
	    double prob = Math.exp (-d2/(2*sigma*sigma));

	    return prob;
	}
	
	public double prob_s (TrackRegion A1, TrackRegion A2, double sigma)
	{		
	    double dUx = A2.get_Ux() - A1.get_Ux();
            double dUy = A2.get_Uy() - A1.get_Uy();
            double dVx = A2.get_Vx() - A1.get_Vx();
            double dVy = A2.get_Vy() - A1.get_Vy();
            
            double d2 = dUx*dUx + dUy*dUy + dVx*dVx + dVy*dVy;
	    
	    double prob = Math.exp (-d2/(2*sigma*sigma));

	    return prob;
	}	   
}