Font rendering (was: Re: Flash player no longer supported, what happens to media9 and Skim?)

[Jim Diamond]

On Mon, Aug  3, 2020 at 00:34 (-0700), Alan E. Davis wrote:

> Off topic

I wouldn't say so.

> and out of order.  Please feel free to ignore this if it is
> completely bonkers.

> I have been pulling my hair out about differences between pdfs
> produced by conversions by ps2pdf, of PostScript output by the Gri
> graphing language.

Well, OK, maybe it is off-topic.

> This did not involved text.  A friend converted on a Mac and got
> much prettier results than my results from ps2pdf, either standalone
> or by way of Inkscape.  My workflow has been working fine for at
> least two years, and other edits with Inkscape too that suddenly are
> not working the same.

> Why I thought this message thread relevant to my issue: I never
> understood previous to the past month that PDFs are rendered
> differently by different software.

In theory, I don't think they should be.  In practice, keep in mind
that the mathematical shapes (of the characters, as well as lines and
curves drawn for other purposes) have to be mapped to a discrete grid
of points.  And, as I understand it, that is where things get ugly.
Different rendering engines can do different things.  In some cases
you might not see the difference, but in some cases you might.

> Even a push or a shove in some direction would be gratefully
> received, toward learning more about this entire process.  It
> troubles me that my work, as trivial as it is---tide graph
> calendars, and other graphs---would not be rendered consistently on
> different media.  I get it that in print, my carefully edited grid
> line widths will look differently on photo paper in a consumer
> printer than on, say, generic printer paper.

> I have been looking at them with evince, okular, acroread (on
> GNU/Linux), and other pdf readers.  My eye is obviously not as
> discerning as yours, because I seem little difference between the
> two images in your attachment.  I don't know what to look for.

Did you read my comment that, for example, the '0' in "10 pt" looks
different to me?  I find the evince rendering far less readable.  For
the bigger fonts, I notice the difference between the Acroread and
the evince rendering, but I find them both quite readable.

> I apologize that this is probably not related to your discussion.

I think it is, indirectly.  The reality is that if we depend on PDF as
a document format we can share with others, it is important for other
people to see your documents how you see them (or as closely matching
as possible).

> I can provide graphics if anyone wants to look at them.

Just out of curiosity, what program did your mac friend use to convert
PS to PDF?  (I'd be interested in some examples, but probably all I
can do is commiserate.)

                                Jim