在WP7中为BitmapImage调用SetSource时出现OutOfMemoryException

Question

I am basically trying to convert a GIF image to a PNG image using the ImageTools library in WP7.

byte[] gifBytes = // GIF image bytes from the web

ImageTools.IO.Decoders.AddDecoder<GifDecoder>();
ImageTools.IO.Encoders.AddEncoder<PngEncoder>();
ImageTools.IO.Png.PngEncoder enc = new PngEncoder();

ExtendedImage gifImage = new ExtendedImage();
gifImage.SetSource(new MemoryStream(gifBytes));                

MemoryStream pngBytes = new MemoryStream();
enc.Encode(gifImage, pngBytes);

BitmapImage pngImage = new BitmapImage(); 
pngImage.SetSource(pngBytes);

As soon as I call pngImage.SetSource(pngBytes) I get OutOfMemoryException .

Maybe there's something else I don't grock here since the debugger also shows that gifImage is 0x0 after I called gifImage.SetSource(new MemoryStream(gifBytes)) . For what's its worth, I've checked that gifBytes[] contains valid GIF bytes...

Any ideas what I am doing wrong?

Answer 1

I am pretty sure the issue is with the ImageTools library that I am using. Not sure how to 100% confirm this, but it seems that if ImageTools encodes faulty image bytes that I try to set as source for the BitmapImage, the BitmapImage will throw an OutOfMemoryException.

So I would call this a bug in both ImageTools library for not being able to encode a perfectly good Gif image to PNG format but also in BitmapImage for throwing the wrong exception in this case.