Re: imread (repost)

[Thomas Weber]

Am Dienstag, den 05.08.2008, 12:43 -0500 schrieb Daniel J Sebald:
> Bill Denney wrote:
> > I would expect to see the axis background color.  If the axis background 
> > color is set to none, then I would expect to see the figure background 
> > color.  I believe that if you set the figure background color to none in 
> > matlab, you see a cross-hatched pattern.  When exporting, I would 
> > anticipate that the graphics backend would take alpha into account 
> > relative to the output device, so if the output was to ps or pdf, it 
> > would convert the background color to the color as visible on the screen.
> > 
> > I'm not saying that this is easy, just that-- to me-- the above is the 
> > right way to do it.
> 
> In my opinion, the right way is for PostScript to handle alpha
>  blending.  Wish it would.  It's the easiest place to implement such a
>  feature, i.e., at the last step just blend the contents together.

I'm not sure I understand, but Postscript seems to support an alpha
channel:
http://tug.org/PSTricks/main.cgi?file=Examples/Colors/colors#transparency

The code example needs a development version of pstricks.

The main problem is that most postscript _viewers_ don't handle
transparency, so one usually converts to PDF.

        Thomas