title: Gaussian filter not effecting the input image in java
body: <p>So I was trying to apply a gaussian filter to an image I have using Java. However the image is not at all being effected by the filter. I am using the inbuilt convolution operator. Could some one point to me what is going wrong ?</p>
  
  <pre><code>public static void main(String[] args) {
    File img = new File( "C:\\Users\\Aditya\\Pictures\\20130729_140153.jpg" );
    BufferedImage a = null;
    try{ 
        a= ImageIO.read( img );
    }
    catch( Exception e ){
        System.out.print( e.toString() );
        return;
    }
    BufferedImage a9 = new BufferedImage( a.getWidth() , a.getHeight() , a.getType() ); 
    float[] matrix = {
      1f/273,4f/273,7f/273,4f/273,1f/273,
      4f/273,16f/273,26f/273,16f/273,4f/273,
      7f/273,26f/273,41f/273,26f/273,7f/273,
      4f/273,16f/273,26f/273,16f/273,4f/273,
      1f/273,4f/273,7f/273,4f/273,1f/273
      };
      BufferedImageOp op = new ConvolveOp( new Kernel( 5, 5, matrix ) );
      a9 = op.filter( a, a9 );
      try{
          ImageIO.write( a9 , "jpg" ,new File( "C:\\Users\\Aditya\\Pictures\\jim.jpg" ));
      }catch( Exception e ){
          System.out.println( e );
      }
      }
  }
  </code></pre>
  
  <p>By not working I mean that there is no difference in the images of a and a9 at all. Its like they have been copied !</p>