BitmapFactory.decodeStream returning null when options are set

Question

I'm having issues with BitmapFactory.decodeStream(inputStream). When using it without options, it will return an image. But when I use it with options as in .decodeStream(inputStream, null, options) it never returns Bitmaps.

What I'm trying to do is to downsample a Bitmap before I actually load it to save memory. I've read some good guides, but none using .decodeStream.

• Handling large Bitmaps

• And here

• Image Processing in Android

WORKS JUST FINE

URL url = new URL(sUrl); HttpURLConnection connection  = (HttpURLConnection) url.openConnection();  InputStream is = connection.getInputStream(); Bitmap img = BitmapFactory.decodeStream(is, null, options); 

DOESN'T WORK

InputStream is = connection.getInputStream(); Bitmap img = BitmapFactory.decodeStream(is, null, options);  InputStream is = connection.getInputStream();  Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true;  BitmapFactory.decodeStream(is, null, options);  Boolean scaleByHeight = Math.abs(options.outHeight - TARGET_HEIGHT) >= Math.abs(options.outWidth - TARGET_WIDTH);  if (options.outHeight * options.outWidth * 2 >= 200*100*2){     // Load, scaling to smallest power of 2 that'll get it <= desired dimensions     double sampleSize = scaleByHeight     ? options.outHeight / TARGET_HEIGHT     : options.outWidth / TARGET_WIDTH;     options.inSampleSize =         (int)Math.pow(2d, Math.floor(         Math.log(sampleSize)/Math.log(2d))); }  // Do the actual decoding options.inJustDecodeBounds = false; Bitmap img = BitmapFactory.decodeStream(is, null, options); 

Answer 1

The problem was that once you've used an InputStream from a HttpUrlConnection to fetch image metadata, you can't rewind and use the same InputStream again.

Therefore you have to create a new InputStream for the actual sampling of the image.

  Options options = new BitmapFactory.Options();   options.inJustDecodeBounds = true;    BitmapFactory.decodeStream(is, null, options);    Boolean scaleByHeight = Math.abs(options.outHeight - TARGET_HEIGHT) >= Math.abs(options.outWidth - TARGET_WIDTH);    if(options.outHeight * options.outWidth * 2 >= 200*200*2){          // Load, scaling to smallest power of 2 that'll get it <= desired dimensions         double sampleSize = scaleByHeight               ? options.outHeight / TARGET_HEIGHT               : options.outWidth / TARGET_WIDTH;         options.inSampleSize =                (int)Math.pow(2d, Math.floor(               Math.log(sampleSize)/Math.log(2d)));      }          // Do the actual decoding         options.inJustDecodeBounds = false;          is.close();         is = getHTTPConnectionInputStream(sUrl);         Bitmap img = BitmapFactory.decodeStream(is, null, options);         is.close(); 

Answer 2

Try wrap InputStream with BufferedInputStream.

InputStream is = new BufferedInputStream(conn.getInputStream()); is.mark(is.available()); // Do the bound decoding // inJustDecodeBounds =true is.reset();   // Do the actual decoding