Marius Jan Klein <mjk524@...2865...> writes:

I want to edit the metadata of pdf- or png-files when creating one of
these files. I do not want to use for example Pypdf because then
Python must read the file first before it can be edited.

Concerning pdf files, there is no current support for that,

Jouni K. Seppänen <jks@...2866...> writes:

Now there is (in the trunk, revision 7964), via the PdfPages mechanism:

from matplotlib.backends.backend_pdf import PdfPages
from pylab import *
pdf = PdfPages('testing.pdf')
d = pdf.infodict()
d['Title'] = 'Testing'
d['Author'] = u'Jouni K. Sepp\xe4nen'

Thanks for your help concerning the pdf files! It was exactly what I was looking for. Is there anything similar for png-files?