Pixelation.java

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public class Pixelation 
{
	public BufferedImage pixelateImage(File inputFile, int boxSize) throws IOException
	{
		
		BufferedImage bufferedImage = ImageIO.read(inputFile);
		
		for(int w = 0 ; w < bufferedImage.getWidth() ; w+=boxSize)
		{
			for(int h = 0 ; h < bufferedImage.getHeight() ; h+=boxSize)
			{
				Color color = new Color(bufferedImage.getRGB(w, h));
				
				Graphics imageGraphics = bufferedImage.getGraphics();
				
				imageGraphics.setColor(color);
				imageGraphics.fillRect(w, h, boxSize, boxSize);
			}
		}
		
		return bufferedImage;
	}
}