package utility;

import ij.process.ByteProcessor;
import ij.process.ImageProcessor;

/**
 * This is a service class.
 * @author Carmelo Pulvirenti
 */

public class Service
{
       /*************************************************************************
        * public constants
        *************************************************************************/
       
       /**
        * SobelX kernel.
        */
       public final static float[] sobelX = new float[] {
              -1, -2,-1,
              0,  0, 0,
              1,  2, 1
       };
       
       
       /**
        * SobelY kernel.
        */
       public final static float[] sobelY = new float[] {
              -1, 0, 1,
              -2, 0, 2,
              -1, 0, 1
       };
       
       
       /**
        * PrewittX kernel.
        */
       public final static float[] prewittX = new float[] {
              -1, -1,-1,
              0,  0, 0,
              1,  1, 1
       };
       
       
       /**
        * PrewittY kernel.
        */
       public final static float[] prewittY = new float[] {
              -1, 0, 1,
              -1, 0, 1,
              -1, 0, 1
       };
       
       
       
       /***********************************************************************************
        * Methods of Support
        * *********************************************************************************/
       
       
       
       
       /**
        * This method copies an ImageProcessor in a ByteProcessor.
        * @param ip the input ImageProcessor.
        * @return ByteProcessor.
        */
       public static ByteProcessor getByteProcessor(ImageProcessor ip)
       {
              ByteProcessor bp = new ByteProcessor(ip.getWidth(),ip.getHeight());
              for (int y = 0; y < ip.getHeight(); y++)
              {
                     for (int x = 0; x < ip.getWidth(); x++)
                     {
                            bp.set(x,y,ip.getPixel(x,y));
                     }
              }
              return bp;
       }
       
       /**
        * This method makes a LoG kernel in an array[].
        * @param window number of row and columns of LoG matrix. It must be an odd.
        * @param sigma value of gaussian.
        * @return the LoG array.
        * @throws IllegalArgumentException if the window is negative zero or it is not odd.
        *                                  If sigma is zero or negative.
        */
       public static float[] initLaplacianOfGaussian(short window, float sigma) throws IllegalArgumentException
       {
              controlInput( window, sigma);
              
              short aperture = (short)(window/2);
              double [][]LacianOfGaussian = new double[2*aperture+1][2*aperture+1];
              float out[]=new float[(2*aperture+1)*(2*aperture+1)];
              double gauss[][]=new double[2*aperture+1][2*aperture+1];
              int k=0;
              double sum=0;
              for(int dy=-aperture;dy<=aperture;dy++)
              {
                     for(int dx=-aperture;dx<=aperture;dx++)
                     {
                            gauss[dx+aperture][dy+aperture]=Math.exp(-(dx*dx+dy*dy)/(2*sigma*sigma));
                            sum+=  gauss[dx+aperture][dy+aperture];
                     }
              }
              // Normalizzation of gaussian
              for(int dy=-aperture;dy<=aperture;dy++)
                     for(int dx=-aperture;dx<=aperture;dx++)
                            gauss[dx+aperture][dy+aperture]=gauss[dx+aperture][dy+aperture]/sum;
              
              
              
              sum=0;
              //Laplacian
              for(int dy=-aperture;dy<=aperture;dy++)
              {
                     for(int dx=-aperture;dx<=aperture;dx++)
                     {
                            LacianOfGaussian[dx+aperture][dy+aperture]=gauss[dx+aperture][dy+aperture]*(dx*dx+dy*dy-2*Math.pow(sigma,2))/Math.pow(sigma,4);
                            sum+=LacianOfGaussian[dx+aperture][dy+aperture];
                     }
              }
              sum=sum/(window*window);
              for(int dy=-aperture;dy<=aperture;dy++)
                     for(int dx=-aperture;dx<=aperture;dx++)
                            out[k++]= (float)(LacianOfGaussian[dx+aperture][dy+aperture]-sum);
              
              return out;
       }
       
       
       
       
       /**
        * This method makes a symmetrical gaussian in an array[].
        * @param window number of row and columns of gaussian matrix. It must be an odd.
        * @param sigma value of gaussian.
        * @return the gaussian array.
        * @throws IllegalArgumentException if the window is negative zero or it is not odd.
        *                                  If sigma is zero or negative.
        */
       public static float[] initGaussianKernel(short window, float sigma) throws IllegalArgumentException
       {
              controlInput( window, sigma);
              short aperture = (short)(window/2);
              float [][]gaussianKernel = new float[2*aperture+1][2*aperture+1];
              float out[]=new float[(2*aperture+1)*(2*aperture+1)];
              int k=0;
              float sum=0;
              for(int dy=-aperture;dy<=aperture;dy++)
              {
                     for(int dx=-aperture;dx<=aperture;dx++)
                     {
                            gaussianKernel[dx+aperture][dy+aperture]=(float)Math.exp(-(dx*dx+dy*dy)/(2*sigma*sigma));
                            sum+= gaussianKernel[dx+aperture][dy+aperture];
                     }
              }
              for(int dy=-aperture;dy<=aperture;dy++)
                     for(int dx=-aperture;dx<=aperture;dx++)
                            out[k++]= gaussianKernel[dx+aperture][dy+aperture]/sum;
              return out;
       }
       
       
       
       /**
        * This function makes a discrete DroGX kernel in a float array.
        * DroGX(x,y,sigma) = (-y/sigma^2)* EXP(-(x^2+y^2)/(2*sigma^2))
        * @param window number of row and columns of gaussian matrix. It must be an odd.
        * @param sigma value of gaussian.
        * @return the array with DroGX kernel.
        * @throws IllegalArgumentException if the window is negative zero or it is not odd.
        *                                  If sigma is zero or negative.
        */
       public static float[] DroGX(short window, float sigma) throws IllegalArgumentException
       {
              controlInput( window, sigma);
              short aperture = (short)(window/2);
              float [][]Drog = new float[2*aperture+1][2*aperture+1];
              float out[]=new float[(2*aperture+1)*(2*aperture+1)];
              int k=0;
              float sum=0;
              for(float dy=-aperture;dy<=aperture;dy=dy+1)
              {
                     for(float dx=-aperture;dx<=aperture;dx=dx+1)
                     {
                            float r=((dx*dx)+(dy*dy));
                            float one=(float)   -(dy/Math.pow(sigma,2));
                            float two=(float)(-r/(2.0*Math.pow(sigma,2)));
                            float three=(float)Math.exp(two);
                            Drog[(int)(dx+aperture)][(int)(dy+aperture)]=(float)( one  * three  );
                            sum+=Drog[(int)(dx+aperture)][(int)(dy+aperture)];
                     }
              }
              sum=sum/(window*window);
              for(float dy=-aperture;dy<=aperture;dy=dy+1)
                     for(float dx=-aperture;dx<=aperture;dx=dx+1)
                            out[k++]= Drog[(int)(dx+aperture)][(int)(dy+aperture)]-sum;
              return out;
       }
       
       
       
       /**
        * This function makes a discrete DroGY kernel in a float array.
        * DroGY(x,y,sigma) = (-x/sigma^2)* EXP(-(x^2+y^2)/(2*sigma^2))
        * @param window number of row and columns of the gaussian matrix. It must be an odd.
        * @param sigma value of gaussian.
        * @return the array with DroGY kernel.
        * @throws IllegalArgumentException if the window is negative zero or it is not odd.
        *                                  If sigma is zero or negative.
        */
       public static float[] DroGY(short window, float sigma) throws IllegalArgumentException
       {
              controlInput( window, sigma);
              short aperture = (short)(window/2);
              float [][]Drog = new float[2*aperture+1][2*aperture+1];
              float out[]=new float[(2*aperture+1)*(2*aperture+1)];
              int k=0;
              float sum=0;
              for(float dy=-aperture;dy<=aperture;dy=dy+1)
              {
                     for(float dx=-aperture;dx<=aperture;dx=dx+1)
                     {
                            float r=((dx*dx)+(dy*dy));
                            float one=(float)   -(dx/Math.pow(sigma,2));
                            float two=(float)(-r/(2.0*Math.pow(sigma,2)));
                            float three=(float)Math.exp(two);
                            Drog[(int)(dx+aperture)][(int)(dy+aperture)]=(float)( one  * three  );
                            sum+=Drog[(int)(dx+aperture)][(int)(dy+aperture)];
                     }
              }
              sum=sum/(window*window);
              for(float dy=-aperture;dy<=aperture;dy=dy+1)
                     for(float dx=-aperture;dx<=aperture;dx=dx+1)
                            out[k++]= Drog[(int)(dx+aperture)][(int)(dy+aperture)]-sum;
              return out;
       }
       
       
       
       /**
        * This method checks the gaussian value.
        * @param window the window of the gaussian.
        * @param sigma the gaussian sigma.
        * @throws IllegalArgumentException if the window is negative zero or it is not odd.
        *                                  If sigma is zero or negative.
        */
       private static void controlInput(short window,float sigma)throws IllegalArgumentException
       {
              if(window%2==0)
                     throw new IllegalArgumentException("Window isn't an odd.");
              if(window<=0)
                     throw new IllegalArgumentException("Window is negative or zero");
              if(sigma<=0)
                     throw new IllegalArgumentException("Sigma of the gaussian is zero or negative.");
       }
}