Re: [ gnuplot-Bugs-1575425 ] "with image" ignores gamma for postscript output (fwd)

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

Ethan Merritt wrote:

> So "settransfer" should be OK by itself.
> However, there is a little more to it...

There was a lot there to read.


> The PostScript Language Reference Manual (3rd Edition) says:
> 
>   Because the effect of the transfer function is device-dependent
>   settransfer should not be used in a page description that is intended
>   to be device-independent.

One would think that the PostScript interpretter would be smart enough to separate the settransfer and possibly remove it.  I guess the assumption is that the interpretter might have its own gamma correction.  Not sure.


> I don't think the setcachedevice restriction is relevant to gnuplot,
> but gnuplot's pattern-fill does use PaintProc in uncolored tiling
> patterns.
> 
> No idea what this means in practice, however.  Perhaps it just means
> that the gamma correction wouldn't affect the color of pattern fill
> areas. That would be no big deal.

I was hoping that the "gsave" isolates the transfer function for the image from that for the rest of the plot.  But I'm not sure if PostScript works that way.

Dan