try {
         File input = new File("digital_image_processing.jpg");
         image = ImageIO.read(input);
         width = image.getWidth();
         height = image.getHeight();

         for(int i=0; i<height; i++){

            for(int j=0; j<width; j++){

               Color c = new Color(image.getRGB(j, i));
               int red = (int)(c.getRed() * 0.299);
               int green = (int)(c.getGreen() * 0.587);
               int blue = (int)(c.getBlue() *0.114);
               Color newColor = new Color(red+green+blue,

               red+green+blue,red+green+blue);

               image.setRGB(j,i,newColor.getRGB());
            }
         }

         File ouptut = new File("grayscale.jpg");
         ImageIO.write(image, "jpg", ouptut);

      } catch (Exception e) {}
   }