[vtkusers] Image cleaned with vtkWin32ImageMapper

[Emiliano Beronich]

Hi,

I was testing the vtkWin32ImageMapper class (obsolete). I found that is 
much faster than vtkOpenGLImageMapper. It can show an image on less than 
the half of the time needed by vtkOpenGLImageMapper. So I don't 
understand why is deprecated. Why?

However I had a trouble with this Mapper. I hope this is not the reason 
because it is obsolete now. When I ask for a Render(), the image is 
shown but immmediately after that it is cleaned with the background 
color. I can show the image if I set on the RenderWindow DoubleBuffer to 
true and SwapBuffer to false.

But I have the same problem when two renderers are superimposed with 
different numbers of layers. The image appears only during a fraction of 
  time.

I don't understand what is happening and the circumstances that make the 
image to dissapear. I would like to show an image with some text above.

Regards,
Emiliano