C# - Convert Texture2D to Image

Started by
5 comments, last by remigius 15 years, 11 months ago
Hi, I need to convert an XNA Texture2D image into a System.Drawing.Image file in order to use it in a Winforms PictureBox but I cannot find a method to convert it. This code snippet shows how to convert it to a GDI Image (the same, right?) with unmanaged code, but I wasn't able to do this, even though I set "Allow Unsafe Code" in the project property, and still, I believe there should be easier methods to convert between these two formats which doesn't force me to go unmanaged? edit - some typos.
Advertisement
Just a quick thought - can you not get the full file name of the Texture2D and then do an Image.FromFile(fullFileName) to load the image into a WinForms Image? That would be the quickest way I think but only if XNA Texture2D's let you get the full file name.

The only other way I can think of is converting the Texture into some raw image format that a winforms Image can use (a byte stream?). Again, I'm not sure if XNA Texture2D has any operations that allow you to do this - perhaps there's an easier way I haven't thought of.

Cheers,

James.

NOTE: I just had a quick look at the Texture2D class on the MSDN, there's a Save() method. You should be able to save the Texture2D as a BMP into a MemoryStream object (like a file but in memory) then use this to generate the WinForms image from. I think what you would do is generate a byte array of the data in the MemoryStream object then create a new Image from the raw data in the byte array. It might sound a bit difficult but it's only a few lines of code. Good luck!
I gave it a quick go and came up with this:

[source lang=csharp]Texture2D texture = Content.Load<Texture2D>("smile");// This only works for 32bbpARGB for the bitmap and Color for the texture, since these formats match.// Because they match, we can simply have Marshal copy over the data, otherwise we'd need to go over// each pixel and do the conversion manually (or through some trick I'm unaware off).byte[] textureData = new byte[4 * texture.Width * texture.Height];texture.GetData<byte>(textureData);System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(               texture.Width, texture.Height,                System.Drawing.Imaging.PixelFormat.Format32bppArgb             );System.Drawing.Imaging.BitmapData bmpData = bmp.LockBits(               new System.Drawing.Rectangle(0, 0, texture.Width, texture.Height),                System.Drawing.Imaging.ImageLockMode.WriteOnly,               System.Drawing.Imaging.PixelFormat.Format32bppArgb             );IntPtr safePtr = bmpData.Scan0;System.Runtime.InteropServices.Marshal.Copy(textureData, 0, safePtr, textureData.Length);bmp.UnlockBits(bmpData);// just some test outputbmp.Save(@"c:\workbench\smile.bmp", System.Drawing.Imaging.ImageFormat.Bmp);


Mind the warning about the surface formats, in case you run into problems later. James's approach is probably more robust, but this should be faster I think.

Don't forget to add a reference to System.Drawing to your project! [smile]
Rim van Wersch [ MDXInfo ] [ XNAInfo ] [ YouTube ] - Do yourself a favor and bookmark this excellent free online D3D/shader book!
This is what I was talking about but I'm not sure if the Save method of a texture2d lets you save to a stream. Have a look and see if it does. Here's some code:

MemoryStream mem = new MemoryStream();yourTexture.Save(mem, ImageFileFormat.Bmp);Image winFormsImage = Image.FromStream(mem);


James
Thanks both of you! Your "safe" conversion worked very well in my solution.

Quote:Original post by JamesLewis
Just a quick thought - can you not get the full file name of the Texture2D and then do an Image.FromFile(fullFileName) to load the image into a WinForms Image? That would be the quickest way I think but only if XNA Texture2D's let you get the full file name.


I have a map editor that loads stuff like NPC data like Texture2D images which represents spritesheets so I can place entities on my map and use a different portion of the sheet based on the entities current direction and so on.


Again, thanks! :)
Quote:Original post by JamesLewis
This is what I was talking about but I'm not sure if the Save method of a texture2d lets you save to a stream. Have a look and see if it does. Here's some code:

*** Source Snippet Removed ***

James


As you suspect, it would seem that it can only save to a filepath. Maybe there's some XNA method which takes a Texture2D and saves it into memory or lets you handle this within the Content system? I'm new to XNA, so I'm not really sure..
Quote:Original post by Nunyah
As you suspect, it would seem that it can only save to a filepath. Maybe there's some XNA method which takes a Texture2D and saves it into memory or lets you handle this within the Content system? I'm new to XNA, so I'm not really sure..


Yeah, I ran into that when trying James's 2nd suggestion. I've looked around a bit more in the API, but can't find anything about saving a texture to memory. Saving the texture out to disk and then loading it back into an image might still be a good alternative though. Of course it depends on what performance you need, but this way you're working with reliable image formats, so it lets you avoid potential pitfalls you might run into with simply copying the data.
Rim van Wersch [ MDXInfo ] [ XNAInfo ] [ YouTube ] - Do yourself a favor and bookmark this excellent free online D3D/shader book!

This topic is closed to new replies.

Advertisement