Am 05.04.2019 um 18:14 schrieb STAMPF Lukas:
Hi,
I guess the reason for that is that if you set a single RenderingHint, you need
to provide all of them or lose the rest from Default.
Yes.
By setting KEY_ANTIALIASING I essentially removed VALUE_RENDER_QUALITY and so
it didn't work.
But now the interesting part: By setting VALUE_RENDER_QUALITY I kept that
setting, but removed the KEY_INTERPOLATION setting.
That would be that there would be no interpolation
(VALUE_INTERPOLATION_NEAREST_NEIGHBOR), which makes sense for bitonal
destination.
I just checked: Setting KEY_RENDERING and KEY_ANTIALIASING and therefore
removing KEY_INTERPOLATION from the RenderingHints improved my situation on
2.0.14. Has something changed there?
No, unless I made a mistake... I took care that people get the same as
before.
I could research this, but then I'd need to get a PDF (please upload to
a sharehoster).
Tilman
Lukas
-----Ursprüngliche Nachricht-----
Von: Tilman Hausherr <[email protected]>
Gesendet: Freitag, 5. April 2019 17:55
An: [email protected]
Betreff: Re: QR Image Detection Down 2.0.13 -> 2.0.14
Hi,
This is weird, RenderingHints.VALUE_RENDER_QUALITY is in the default settings?!
See in the source code, PDFRenderer.createDefaultRenderingHints().
antialiasing is off when bitonal destination.
Tilman
Am 05.04.2019 um 17:48 schrieb STAMPF Lukas:
Thanks, seems like it wasn't the antialiasing. Turning it off and on didn't
change the results between 2.0.13 and 2.0.14. What did help however was
hints.put(RenderingHints.KEY_RENDERING,
RenderingHints.VALUE_RENDER_QUALITY);
Setting this on 2.0.14 seems to restore the 2.0.13 behavior. Could be
coincidence though. Need to verify it with a larger amount of documents first.
Has something about this setting changed between versions when rendering in
BINARY mode?
Lukas
-----Ursprüngliche Nachricht-----
Von: Tilman Hausherr <[email protected]>
Gesendet: Freitag, 5. April 2019 17:00
An: [email protected]
Betreff: Re: QR Image Detection Down 2.0.13 -> 2.0.14
Yes, PDFRenderer now allows to pass rendering hints.
Tilman
Am 05.04.2019 um 16:42 schrieb STAMPF Lukas:
Hi,
I am using PDFBox to generate BufferedImages which I feed to ZXing
3.3.3 to do QR scanning. When I updated from 2.0.13 to 2.0.14 I
noticed a severe reduction in scanning reliability. I guess its
related to this change
https://issues.apache.org/jira/browse/PDFBOX-4391
This is the render command I use:
bim = pdfRenderer.renderImageWithDPI(pageCounter, dpi,
ImageType.BINARY);
I try multiple dpi settings between 150 and 300, to increase my changes to find
a QR code.
Is there some flag I can set to test out if the antialiasing causes this?
Kind regards
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