import org.opencv.core.*;
import org.opencv.calib3d.*;
import org.opencv.highgui.*;
import org.opencv.imgproc.*;
import java.util.*;
import java.io.*;

class VisualMeasureExample {

  static{ System.loadLibrary(Core.NATIVE_LIBRARY_NAME); }

  public static double PIXEL_TO_MM = 688.0 / 20.0;
  public static double MM_TO_PIXEL = 20.0 / 688.0;
  
  public static double estimateMM2Pixel(String referenceImgFile) {
	  Mat ref_img = new Mat();
	  ref_img = Highgui.imread(referenceImgFile, Highgui.CV_LOAD_IMAGE_GRAYSCALE);
	  //Imgproc.equalizeHist(ref_img, ref_img);
	  double thresh_value = 128;
	  Mat binary_img = new Mat();
	  thresh_value = Imgproc.threshold(ref_img, binary_img, thresh_value, 255, Imgproc.THRESH_OTSU);
	  Highgui.imwrite("ref_gray_histeq.png", binary_img);
	  
	  Mat dist_img = new Mat();
	  Imgproc.distanceTransform(binary_img, dist_img, Imgproc.CV_DIST_L2, Imgproc.CV_DIST_MASK_PRECISE);
	  
	  
	  float[] dist_vals = new float[dist_img.rows()*dist_img.cols()];
	  dist_img.get(0,0, dist_vals);
	  
	  float max = 0.0f;
	  for (int i = 0; i < dist_img.rows()*dist_img.cols(); i++) {
		  if ( max < dist_vals[i]) {
			  max = dist_vals[i];
		  }
	  }
	  
	  System.out.println("max = " + max);
	  
	  Highgui.imwrite("ref_distmap.png", dist_img);
	  
	  return (double) (20.0 / (2.0 * max) ); // square is 20 mm
	  
	  
	  
	  
	  
  }
  
  public static void main(String[] args) {
  
	Mat input_img = new Mat();
	Mat gray_img = new Mat();
	input_img = Highgui.imread("csavaranyaM5_telecentric_WD175mm.bmp");
	
	
	VisualMeasureExample.MM_TO_PIXEL = VisualMeasureExample.estimateMM2Pixel("reference_sqaure_telecentric_WD175mm.bmp");
	
	Imgproc.cvtColor(input_img, gray_img, Imgproc.COLOR_BGR2GRAY);
	
	Highgui.imwrite("csavaranya_gray.png", gray_img);
	
	Mat binary_img = new Mat();
	double thresh_value = 220;
	
	thresh_value = Imgproc.threshold(gray_img, binary_img, thresh_value, 255, Imgproc.THRESH_BINARY_INV);
	
	System.out.println("threshold value = "  + thresh_value);
	
	Mat kernel = new Mat(3,3, CvType.CV_8U);
	
	Mat eroded_img = new Mat();
	Mat contour_img = new Mat();
	
	Imgproc.erode(binary_img, eroded_img, kernel, new Point(-1,-1), 1, Imgproc.BORDER_CONSTANT, new Scalar(0));
	
	Core.bitwise_xor(binary_img,eroded_img, contour_img);
	
	Mat dilated = new Mat();
	Imgproc.dilate(contour_img, contour_img, kernel, new Point(-1,-1), 1, Imgproc.BORDER_CONSTANT, new Scalar(0));
	
	
	Highgui.imwrite("csavaranya_contour.png", contour_img);

	Mat circles = new Mat();
	Imgproc.HoughCircles(contour_img, circles, Imgproc.CV_HOUGH_GRADIENT, 2, gray_img.width());
	Mat circle_img = new Mat(gray_img.rows(), gray_img.cols(), CvType.CV_8U);
	circle_img = gray_img.clone();
	
	System.out.println("circles = " + circles.dump());
	
	float[] circleData = new float[3];
	circles.get(0,0, circleData);
	/*
	float[] cx = new float[1];
	float[] cy = new float[1];
	float[] r = new float[1];
	circles.get(0,0, cx);
	circles.get(0,1, cy);
	circles.get(0,2, r);
	*/ 
	
	Imgproc.cvtColor(circle_img, circle_img, Imgproc.COLOR_GRAY2BGR);
	Core.circle(circle_img, new Point(circleData[0], circleData[1]), (int)(circleData[2]), new Scalar(0,0,255), 3);
	Highgui.imwrite( "circle.png", circle_img );
	
	System.out.println("Radius = " + (circleData[2] * VisualMeasureExample.MM_TO_PIXEL) + "mm");
	System.out.println("Diameter = " + (2* circleData[2] * VisualMeasureExample.MM_TO_PIXEL) + "mm");
	

  }


}