title: Which files does not reduce its size after compression
body: <p>I have written a java program for compression. I have compressed some text file. The file size after compression reduced. But when I tried to compress PDF file. I dinot see any change in file size after compression.</p>
  
  <p>So I want to know what other files will not reduce its size after compression.</p>
  
  <p>Thanks
  Sunil Kumar Sahoo</p>