Add the word "slow" to preserved unreferenced resources docs (fixes #380)

This makes it more likely for someone who notices a big slow-down in
page splitting to discover the option.
This commit is contained in:
Jay Berkenbilt 2019-11-09 11:42:16 -05:00
parent 5508f74603
commit c9cc83621b
1 changed files with 15 additions and 9 deletions

View File

@ -1862,10 +1862,14 @@ outfile.pdf</option>
Starting with qpdf 8.1, when splitting pages, qpdf ordinarily
attempts to remove images and fonts that are not used by a
page even if they are referenced in the page's resources
dictionary. This option suppresses that behavior. The only
reason to use this is if you suspect that qpdf is removing
resources it shouldn't be removing. If you encounter that
case, please report it as a bug.
dictionary. This option suppresses that behavior. There are
few reasons to use this option. One reason to use this is if
you suspect that qpdf is removing resources it shouldn't be
removing. If you encounter that case, please report it as a
bug. Another reason is that the new behavior can be much
slower for files that include a very large number of images or
other XObjects on a page. In that case, using this option will
return qpdf to the old behavior and speed.
</para>
<para>
See also <option>--preserve-unreferenced</option>, which does
@ -6013,11 +6017,13 @@ print "\n";
not actually referenced and omits them from the output file.
This change can cause a significant reduction in the size of
split PDF files for files created by some software packages.
Prior versions of qpdf would believe the document metadata
and sometimes include all the images from all the other
pages even though the pages were no longer present. In the
unlikely event that the old behavior should be desired, it
can be enabled by specifying
In some cases, it can also make page splitting slower. Prior
versions of qpdf would believe the document metadata and
sometimes include all the images from all the other pages
even though the pages were no longer present. In the
unlikely event that the old behavior should be desired, or
if you have a case where page splitting is very slow, the
old behavior (and speed) can be enabled by specifying
<option>--preserve-unreferenced-resources</option>. For
additional details, please see <xref
linkend="ref.advanced-transformation"/>.