clipka <ano### [at] anonymousorg> wrote:

> I think the paramount critera should be that (a) the files can be easily
> exchanged between applications as well as via the internet, and (b) the
> file format does not use lossy compression.

Yes, I do see the need for that. But as a practical matter, I wonder if there is
a discernable visual difference between a .png file and one saved as a
highest-quality .jpeg? (I suppose that's open to debate.) The real point being
that .jpeg *is* a universal standard (lossy, of course); but more importantly,
it has no embedded gamma (AFAIK!!)--which means that how it shows up in
application X is basically the same as in app Y or app Z--regardless of how
those apps deal with embedded gamma in an image. I guess mt main worry is this:
Not all of us have the *latest and greatest* versions of
image-manipulation/viewing software, to view 'correct' .png images in. (My own
version of Photoshop is quite outdated, for example, and AFAIK doesn't read
embedded gamma correctly. And I'm even wondering about the latest version of
Firefox!) I suppose that most/all up-to-date versions of software have addressed
this issue--but that's just a guess. In the final analysis: Can we expect a .png
image to show up correctly even in all 'modern' software? A .jpeg image
eliminates that question (given it's image-quality shortcomings.)

> As for gamma, note that gamma issues also exist with any other image
> format..

True--but that's across-the-board, as you say. I.e., with an image format
lacking an embedded gamma, it's a monitor/system-set-up problem, not an
image-specific one.
>
> For a user adhering to best practices, /at worst/ PNG will still be just
> as good as any other formats.
>

Given *best practices* of course. :-P  If such a .png 'default' is made a part
of POV-Ray, I can only hope that the documentation will make it clear as to what
those best practices are. In the past, this situation has been a can of worms.

Ken

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