Re: RGBA image mode (patchset #1589067)

[Daniel J S. <dan...@ie...>]

Ethan A Merritt wrote:

> - The only real use I can think of:  painting a heat map onto a surface in 3D,
>   for instance a pm3d representation of electrostatic potential at the surface
>   of a cube, and then making it semi-transparent so that you can see other plot
>   elements (3D vector fields?) through it.  The thing is, you can *already* do
>   this in gnuplot, using the new "set style fill transparent solid <alpha>" and
>   pm3d quadrilaterals.  It would only require an RGBA mode if you had a need to
>   map a pre-existing image onto the surface, and even then only if each pixel
>   had a separate alpha value.  Are there any such real-world cases?

This seems the best example I can think of.  But I, like Timothée, imagine the 
general alpha channel could be of benefit to someone, especially in the areas of 
image processing.

And if only for the ability to draw non-rectangular images it might be worth it. 
  With that, someone could put a logo on the plot or something.  (Then again, 
that might be possible similar to that cow milk production example.)

Dan