//
// Implementation of 'Binary Image'
// 
// The following code creates a binary image by replacing every
// pixel by it's compliment by either 0 or 255 depending on the
// threshold of that region
//

public class binaryImage extends Object
{
	private int inPixels[], width, height;
	
	binaryImage(int Pixels[], int w, int h)		// the constructor
	{
		inPixels = new int[Pixels.length];
		inPixels = Pixels;
		width = w;
		height = h;
	}


	// The following function binarizes a part of the image
	// startx,starty,endx and endy are the boundaries of the rectangular area
	
	public int[] binarizeSelection(int startx, int starty, int endx, int endy, int thold)
	{
		int outPixels[] = new int[inPixels.length];
		
		outPixels = inPixels;
		
		for (int y = starty; y < endy; y++)
			for (int x = startx; x < endx; x++)
			{
				if (inPixels[y*width + x] > thold)
					outPixels[y*width + x] = 255;
				else
					outPixels[y*width + x] = 0; 
			}	
		
		return outPixels;
	}
	
	
	// The following function does local binarization by dividing the image in
	// 4 quadrants. Each quadrant can have a different threshold. For global
	// binarization, set all thresholds to the same value.
	
	public int[] binarize(int thold1,int thold2,int thold3,int thold4)
	{
		int outPixels[] = new int[inPixels.length];
		
		for (int y = 0; y < height/2; y++)
			for (int x = width/2; x < width; x++)
			{
				if (inPixels[y*width + x] > thold1)
					outPixels[y*width + x] = 255;
				else
					outPixels[y*width + x] = 0; 
			}
					
		for (int y = 0; y < height/2; y++)
			for (int x = 0; x < width/2; x++)
			{
				if (inPixels[y*width + x] > thold2)
					outPixels[y*width + x] = 255;
				else
					outPixels[y*width + x] = 0; 
			}
					
		for (int y = height/2; y < height; y++)
			for (int x = 0; x < width/2; x++)
			{
				if (inPixels[y*width + x] > thold3)
					outPixels[y*width + x] = 255;
				else
					outPixels[y*width + x] = 0; 
			}
						
		for (int y = height/2; y < height; y++)
			for (int x = width/2; x < width; x++)
			{
				if (inPixels[y*width + x] > thold4)
					outPixels[y*width + x] = 255;
				else
					outPixels[y*width + x] = 0; 
			}

		return outPixels;
	}
}