How to edit a WritableBitmap.BackBuffer in non UI thread?

Question

My application runs CPU-heavy algorythms to edit an Image placed at a WPF window. I need the edition to be done in a background thread. However trying to edit the BackBuffer

Answer 1

As Clemens said, this is impossible.

You have three choices:

1) Do your editing in a buffer and blit when finished as Clemens suggests.

2) Do the editing in very small chunks and schedule them at a nice priority on the GUI thread. If you keep your work chunks small enough, the GUI will remain responsive, but obviously this complicates the edit code.

3) Combine 1 & 2. Edit small chunks in another thread, then blit each chunk as it completes. This keeps GUI responsive without using memory for a full back buffer.