Re: Latest lilypond git master creating PDF 1.4 files instead of 1.7

[H. S. Teoh]

On Sat, Sep 11, 2021 at 09:35:00PM +0200, Valentin Petzel wrote:
> From what I see pdftops appears to be intelligent enough to rasterize
> the file only if it does actually contain transparency. If it does it
> uses a much less smooth rasterization that is probably not fit for
> printing, so be careful with this! See the attached picture for a
> comparisation, the left one is poppler (pdftops), the right one gs
> (pdf2ps).

I experimented with pstops, and it does seem to produce a non-rasterized
PS file, which can then be converted back to PDF without transparency,
thus sidestepping this issue.  I'll use that as a workaround for now.
:-D


[...]
> But anyway. Usually there should not be any reason to convert from pdf
> to ps, apart from printing or doing ps-style manipulations. But ps is
> only a subset of pdf, so the conversion in that direction cannot
> always be done in an acceptable manner.

I discovered that converting the pdf to ps and back again significantly
reduces the file size.  So it's kinda my poor-man's way of compressing
pdfs.  Of course, this only works if your pdf doesn't contain any
features incompatible with ps, which in my case is true.  And now that I
know that pdftops does a proper job with the conversion even when there
is transparency, it's a sufficiently-acceptable solution to this issue.


> Also I have tested gv on the pdf-files, but I’m not experiencing these
> delays. 
[...]

I wonder if it has to do with the amount of available RAM, as my PC is
10+ years old, so on a more modern machine the difference would be
unnoticeable.


T

-- 
If it tastes good, it's probably bad for you.