title: How can I load a bitmap image and manipulate individual pixels?
body: <p>I want to load a single large bitmap image from a file, run a function that manipulates individual pixels and then re save the bitmap.</p>
  
  <p>File formats can be either PNG or BMP, and the manipulating function is something simple such as:</p>
  
  <pre><code>if r=200,g=200,b=200 then +20 on all values, else -100 on all values
  </code></pre>
  
  <p>The trick is being able to load a bitmap and being able to read each pixel line by line</p>
  
  <p>Is there standard library machinery in Java that can handle this I/O?</p>
  
  <p>(The bitmap will need to be several megapixels, I need to be able to handle millions of pixels)</p>