//Kevin Liu
//module for the median filter
import java.io.*;
import java.util.*;

class Median 
{	
        private int[][] data;
	private int numRow;
	private int numCol;
	private int[][] result;
	
	//takes as input the two dimensional array representing the input image
	public Median(int[][] image, int row, int column) 
	{
		data = image;		
		numRow = row;
		numCol = column;
		result = new int[numRow][numCol]; // this represents the resulting filtered image	
	}	
	public int[][] process()
        {              
        	int column;
		int row;
		int r;
		int c;
		int iterator;
		int[] surround = new int[9];
		// slides the window across the image and copies the nine pixels inside into an array called "surround"
		for(row = 0; row < numRow; row++)
		{
			for(column = 0; column < numCol; column++)
			{								
				if(row == 0 || row == numRow-1 || column == 0 || column == numCol-1)
				{
					result[row][column] = data[row][column];
					continue;
				}
				iterator = 0;
				for(r=row-1; r < row+2; r++)
					for(c=column-1; c < column+2; c++)
					{	
						surround[iterator] = data[r][c];
						iterator++;
					}
				result[row][column] = insertionSortMedian(surround, 9); //calls the sorting method and 											enters the median value
				
			}	
		}
		return result;		
        }
	
	private int insertionSortMedian(int numbers[], int array_size) //sorts array and returns median value
	{
  		int i, j, index;

		for(i = 0; i < array_size; i++)
			System.out.print(numbers[i] + " ");
		System.out.println();

  		for (i=1; i < array_size; i++)
  		{
    			index = numbers[i];
    			j = i;
    			while ((j > 0) && (numbers[j-1] > index))
    			{
      				numbers[j] = numbers[j-1];
      				j = j - 1;
    			}
    			numbers[j] = index;
  		}

		for(i = 0; i < array_size; i++)
			System.out.print(numbers[i] + " ");
		System.out.println();
		
		System.out.println(numbers[array_size/2]);		
		return (numbers[array_size/2]);
	}
	
	
}