public Picture shrink(Picture pic)
{
   Picture smaller = new Picture(pic.getWidth()/2, pic.getHeight()/2);
   Pixel sourcePixel = null;
   Pixel targetPixel = null;

   for(int sourceX = 0, targetX = 0; sourceX < pic.getWidth(); sourceX+=2, targetX++)
   {
     for(int sourceY = 0, targetY = 0; sourceY < pic.getHeight(); sourceY+=2, targetY++)
     {
       sourcePixel = pic.getPixel(sourceX, sourceY);
       targetPixel = smaller.getPixel(targetX, targetY);
       targetPixel.setColor(sourcePixel.getColor());
     }
   }

   return smaller;
}


public Picture enlarge(Picture pic)
{
   Picture bigger = new Picture(pic.getWidth()*2, pic.getHeight()*2);
   Pixel sourcePixel = null;
   Pixel targetPixel = null;

   for(double sourceX = 0, targetX = 0; sourceX < pic.getWidth(); sourceX+=0.5, targetX++)
   {
     for(double sourceY = 0, targetY = 0; sourceY < pic.getHeight(); sourceY+=0.5, targetY++)
     {
       sourcePixel = pic.getPixel((int)sourceX, (int)sourceY);
       targetPixel = bigger.getPixel((int)targetX, (int)targetY);
       targetPixel.setColor(sourcePixel.getColor());
     }
   }

   return bigger;
}