title: Android: How to render a streaming image on-the-fly to ImageView without loading the complete bitmap?
body: <p>I am loading an image from a URL to be shown in an ImageView. The standard way is to create a bitmap as follows (where the InputStream <code>is</code> has been obtained from the URL):</p>
  
  <pre><code>Bitmap bm = BitmapFactory.decodeStream(is);
  </code></pre>
  
  <p>But I am dealing with large images, and I want to start displaying pixels before the entire image is loaded in the bitmap i.e. I want achieve progressive rendering of the image (similar to loading of large images in web browsers). If the image is, for instance, an interlaced PNG, this will allow me to show a lower quality image to users while they wait for the full image to load.
  Basically, I want to achieve rendering as shown in <a href="http://www.codinghorror.com/blog/2005/12/progressive-image-rendering.html">http://www.codinghorror.com/blog/2005/12/progressive-image-rendering.html</a></p>
  
  <p>I know if I could implement a PNG decoder, or use an opensource implementation, I could modify it to render pixels to the ImageView's bitmap as soon as I read them, but that looks like a mammoth effort for what I intend.</p>