I don’t know if this helps narrow it down: It seems to be related to having a transparent background. The JPEG looked OK because it has a white rectangle underneath the text; the PNG and the printing/print to PDF had a transparent background. Adding a white rectangle to the background of the MemoryDC before Blit-ing to the PrintDC makes the printing quality look fine. However, since the whole point of a PNG (or at least, the point that distinguishes it from a JPG in this case) is that it has a transparent background, I can’t do that with the PNG.
Again, this seems to be an Intel/PPC difference; at least, the only reports I’ve had about it have come from PPC users, and no Intel machine I’ve tried has given a problem.
I thought I remembered reading something about transparent backgrounds in wx/Mac, but Google doesn’t seem to be helping me right now.
I’ll file it as a bug report, anyway.
···
---------- Forwarded message ----------
From: Robin Dunn robin@alldunn.com
To: wxPython-users@lists.wxwidgets.org
Date: Tue, 05 Jun 2007 10:01:53 -0700Subject: Re: [wxPython-users] bitmap.SaveFile - resolutions
Ian York wrote:This is prepared on an Intel Mac, running MacOS10.4.9. On the three
Intel Macs I’ve tried, both the JPEG and the PNG come out looking fine,as does printing and saving the print as a PDF using the Mac’s Print
Dialog built-in Save As PDF option.However, on PPC macs (also running 10.4.9) the JPEG comes out looking
fine, but the PNG looks terrible; the text, in particular, comes out asmere blocks of smeary black. The same is true on the PDF from the Save
As PDF option.Is this a known issue? -an OS or hardware issue? Is there a workaround,
or am I doing something wrong I can fix?This is the first I’ve heard of it, please enther a bug report about it
with a category of “wxMac specific”. It sounds to me like it could be
an endianness issue (order of bytes in integer values.)–
Robin Dunn
Software Craftsman
http://wxPython.org Java give you jitters? Relax with wxPython!
–
Ian York (iayork@iayork.com) <http://www.iayork.com/>
"-but as he was a York, I am rather inclined to suppose him a
very respectable Man." -Jane Austen, The History of England