StegoImage

/**
 * @author...
 * @version October 2019
 */
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.awt.Color;
import java.lang.IllegalArgumentException;

public class StegoImage
{
    BufferedImage image;
    int width;
    int height;
    public StegoImage(String filename)
    {
        //create a StegoImage by reading an image from a file.
        try
         {
            File file = new File(filename);
            image = ImageIO.read(file);
            width = image.getWidth();
            height = image.getHeight();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        catch (NullPointerException e)
        {
            System.out.println("NullPointerException Caught");
        }
        if(image.getHeight() <= 0 && image.getWidth() <= 0)
        {
            throw new IllegalArgumentException("Please input an image with valid dimensions");
        }
    }

    public BufferedImage getImage()
    {
        image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        return image;
    }

    public int getHeight()
    {
        height = StegoViewer.IMG_HEIGHT;
        return height;
    }

    public int getWidth()
    {
        width = StegoViewer.IMG_WIDTH;
        return width;
    }

    public void scaleImage(int div, int mult)
    {
        //Modify this image by changing every pixel
        for(int y = 0; y < image.getHeight(); y++)
        {
           for(int x = 0; x < image.getWidth(); x++)
           {
               if(div > 0 && mult > 0)
               {
                   Color s = new Color(image.getRGB(x,y));
                   int r = s.getRed();
                   int g = s.getGreen();
                   int b = s.getBlue();

                   r = (r/div)*mult;
                   g = (g/div)*mult;
                   b = (b/div)*mult;

                   image.setRGB(r,g,b);
               }
               else
               {
                   break;
               }
           }
        }
    }

    public void clearLowBit()
    {
        //Modify this image by setting the lowest bit of each pixel colour to 0
        for(int y = 0; y < image.getHeight(); y++)
        {
           for(int x = 0; x < image.getWidth(); x++)
           {

               Color a = new Color(image.getRGB(x,y));
               int r = a.getRed();
               int g = a.getGreen();
               int b = a.getBlue();

               image.setRGB(0,0,0);
           }
        }
    }
    public void setZeroOne()
    {
        //Modify this image by thresholding its pixels to 0 or 1 in each pixel colour
        for(int y = 0; y<image.getHeight(); y++)
        {
            for(int x = 0; x < image.getWidth(); x++)
            {
               int pixel = image.getRGB(x,y);
               int r = (pixel >> 16) & 0xff;
               int g = (pixel >> 8) & 0xff;
               int b = pixel & 0xff;
               r = 0;
               g = 0;
               b = 1;

               pixel = (r<<16) | (g<<8) | b;
               image.setRGB(x,y,pixel);
            }
        }
    }

    public void setBlackWhite()
    {
        //Modify this image by upscaling each 0,1 pixel to a greyscale for viewing
        for(int y = 0; y < image.getHeight(); y++)
        {
            for(int x = 0; x < image.getWidth(); x++)
            {
               Color blkWht = new Color(image.getRGB(x,y));
               int p = image.getRGB(x,y);
               int r = (p>>16) & 0xff;
               int g = (p>> 8) & 0xff;
               int b = (p) & 0xff;

               int grey = (b/b)+255;

               image.setRGB(x,y,grey);
            }
        }
    }

    public void setToLowBit()
    {
        //Modify this image by setting each pixel to just its low bit value (0 or 1)
        for(int y = 0; y < image.getHeight(); y++)
        {
            for(int x = 0; x < image.getWidth(); x++)
            {
                Color w = new Color(image.getRGB(0,0));
                int r = w.getRed();
                int g = w.getGreen();
                int b = w.getBlue();
                int lowBit = (r<<16)|(g<<8)|b;

                image.setRGB(r,g,lowBit);
            }
        }
    }

    public void mergeImage(StegoImage newimage)
    {
        //Modify this image to become this + newimage by adding each of their RGB pixels
        for(int y = 0; y < image.getHeight(); y++)
        {
            for(int x = 0; x < image.getWidth(); x++)
            {
                StegoImage img1 = new StegoImage("");
                StegoImage img2 = new StegoImage("");

                Color one = new Color(img1.image.getRGB(x,y));
                Color two = new Color(img2.image.getRGB(x,y));

                int r = one.getRGB() + two.getRGB();
                int g = one.getRGB() + two.getRGB();
                int b = one.getRGB() + two.getRGB();

                newimage.image.setRGB(r,g,b);
            }
        }
    }
}