Source src = session.needSource(info.getOriginalURI());
ImageInputStream imgStream = ImageUtil.needImageInputStream(src);
SeekableStream seekStream = new ImageInputStreamSeekableStreamAdapter(imgStream);
PNGImageDecoder decoder = new PNGImageDecoder(seekStream, new PNGDecodeParam());
RenderedImage image = decoder.decodeAsRenderedImage();
// need transparency here?
return new ImageRendered(info, image, null);
}