Reading RAW image files as GDI+ bitmaps [closed]

Question

Is there a good way to read RAW image files (especially Canon CR2 and Adobe DNG files) as GDI+ bitmaps that is reasonably fast?

I found an example running under WPF that would read an image using any installed image codec and then display it in an image control. And I modified this example to create a GDI+ bitmap by writing the WPF image to a MemoryStream and creating the Bitmap from that. But this process is slow! Horribly slow! Opening a simple image takes around 10 seconds on my computer. This solution also requires references to the WPF assemblies and that doesn't feel right, especially not since I would like to run the code in an ASP.NET project.

There are programs that will do batch conversions of the images, but I would prefer converting the images dynamically when requested.

So, any suggestions?

Answer 1

Here is a C# port of dcraw, albeit rather old (v8.88) which could be adapted to include newer Canon models:
https://sourceforge.net/projects/dcrawnet/

EDIT :
I just got it to work in my own project for reading EXIF data from RAW files:

1. Open project properties and set Output Type to Class Library.
2. Recompile.
3. Add a reference to the DLL in your own project.
4. Add using dcraw; at the top.

5. Declare these lines of code:

   DcRawState state = new DcRawState();
   state.inFilename = filename;
   state.ifp = new RawStream(filename);
   
   
   Identifier id = new Identifier(state);
   id.identify(state.ifp);
   

Now check out all the goodies inside state (assuming your RAW file is supported and didn't cause an exception ;)