Texture2D.LoadImage texture format override problem

Hi.
I use LoadImage() to work with external textures (JPG and PNG files) in my project. It has a problem with texture format preserving. For example I have 8-bit JPG (or PNG) texture (gray) and I want to upload it to Alpha8 format texture using next piece of code:

Code (CSharp):

1. Texture2D outTexture = new Texture2D( 1, 1, TextureFormat.Alpha8, false, true );
2. if ( outTexture.LoadImage( atlasRawBytes.bytes, true ) )
3. {
4.     // use texture..
5. }

But texture format is overrided to RGB24 after loading. I can use LoadRawTextureData() to upload manually decoded jpg, but c# jpg decoding is too slow.
Could LoadImage() have a flag to preserve specified texture format or to respect file texture format?
Thanks.

 

You can see this behaviour is documented in the Texture2D.LoadImage docs (here: http://docs.unity3d.com/ScriptReference/Texture2D.LoadImage.html):

 

Unity should just assign alpha channel instead of changing the format.