Poor quality image scaling
Hi, Picture of the issue: http://i43.tinypic.com/2hq4ilf.png I use 256x256 PNG admonition images. They are specced in the generated .fo file as having content-width of 36 pt, which is half an inch I understand. At a target DPI of 300, this would be 150x150. As you can see in the pic, it's obvious FOP uses a poor quality image scaling algorithm, nearest-neighbor, or point sampling in GL terms. How can I tell FOP to use a better quality algorithm? Ideally at least bicubic, but bilinear would be a great improvement too. Thanks, - Lauri PS: Please CC me, not subscribed. - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Your screen capture is not half an inch, so we don't know where the scaling comes from. Have you tried to zoom in with your PDF viewer? If you still have questions please provide original image, your fo file, any fop.xconf if using it, and the generated pdf. I was unable to reproduce the issue you describe with a stock png image. On Tue, Jul 2, 2013 at 11:07 AM, Lauri Kasanen c...@gmx.com wrote: Hi, Picture of the issue: http://i43.tinypic.com/2hq4ilf.png I use 256x256 PNG admonition images. They are specced in the generated .fo file as having content-width of 36 pt, which is half an inch I understand. At a target DPI of 300, this would be 150x150. As you can see in the pic, it's obvious FOP uses a poor quality image scaling algorithm, nearest-neighbor, or point sampling in GL terms. How can I tell FOP to use a better quality algorithm? Ideally at least bicubic, but bilinear would be a great improvement too. Thanks, - Lauri PS: Please CC me, not subscribed. - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Luis Bernardo lmpmbernardo at gmail.com writes: Your screen capture is not half an inch, so we don't know where the scaling comes from. Have you tried to zoom in with your PDF viewer? If you still have questions please provide original image, your fo file, any fop.xconf if using it, and the generated pdf. I was unable to reproduce the issue you describe with a stock png image. Here's a zip containing the requested files: http://bayfiles.net/file/S52n/Gw7iCz/fopzip.zip The image in the PDF looks bad at all zoom levels (100%, fit to window, fit to width, 300%, ...). Thanks, - Lauri - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Can you attach the file? I am unable to download it. On Tue, Jul 2, 2013 at 3:15 PM, Lauri Kasanen c...@gmx.com wrote: Luis Bernardo lmpmbernardo at gmail.com writes: Your screen capture is not half an inch, so we don't know where the scaling comes from. Have you tried to zoom in with your PDF viewer? If you still have questions please provide original image, your fo file, any fop.xconf if using it, and the generated pdf. I was unable to reproduce the issue you describe with a stock png image. Here's a zip containing the requested files: http://bayfiles.net/file/S52n/Gw7iCz/fopzip.zip The image in the PDF looks bad at all zoom levels (100%, fit to window, fit to width, 300%, ...). Thanks, - Lauri - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Luis Bernardo lmpmbernardo at gmail.com writes: Can you attach the file? I am unable to download it. Gmane does not let me do that. Trying another hoster: https://anonfiles.com/file/ba2371af6890b4f038dbfe0665d49c96 http://stashbox.org/v/1170761/fopzip.zip - Lauri - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Am 02.07.2013 16:15, schrieb Lauri Kasanen: Luis Bernardo lmpmbernardo at gmail.com writes: Your screen capture is not half an inch, so we don't know where the scaling comes from. Have you tried to zoom in with your PDF viewer? If you still have questions please provide original image, your fo file, any fop.xconf if using it, and the generated pdf. I was unable to reproduce the issue you describe with a stock png image. Here's a zip containing the requested files: http://bayfiles.net/file/S52n/Gw7iCz/fopzip.zip The image in the PDF looks bad at all zoom levels (100%, fit to window, fit to width, 300%, ...). It does look fine here in Acroread as well as in Okular; I would not expect FOP to actually do the scaling but the PDF viewer, but maybe the devs can answer that better than I do. Philipp - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Am 02.07.2013 17:54, schrieb Philipp Wagner: Am 02.07.2013 16:15, schrieb Lauri Kasanen: Luis Bernardo lmpmbernardo at gmail.com writes: Your screen capture is not half an inch, so we don't know where the scaling comes from. Have you tried to zoom in with your PDF viewer? If you still have questions please provide original image, your fo file, any fop.xconf if using it, and the generated pdf. I was unable to reproduce the issue you describe with a stock png image. Here's a zip containing the requested files: http://bayfiles.net/file/S52n/Gw7iCz/fopzip.zip The image in the PDF looks bad at all zoom levels (100%, fit to window, fit to width, 300%, ...). It does look fine here in Acroread as well as in Okular; I would not expect FOP to actually do the scaling but the PDF viewer, but maybe the devs can answer that better than I do. Actually, extracting the images using pdfimages (from poppler-utils) confirms that, the images are 256x256 px inside the PDF, just as the original ones. So all scaling comes from the PDF viewer. Philipp - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Philipp Wagner lists at philipp-wagner.com writes: It does look fine here in Acroread as well as in Okular; I would not expect FOP to actually do the scaling but the PDF viewer, but maybe the devs can answer that better than I do. Further googling lead me to see that there's a flag embedded in the PDF saying whether or not an image should be interpolated. http://superuser.com/questions/358134/pdf-rendering-of-images-seems-to-vary- from-viewer-to-viewer-with-blurring https://bugs.freedesktop.org/show_bug.cgi?id=25268 It appears that FOP does not set this flag. Any comments? - Lauri - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
Re: Poor quality image scaling
Hi, please consider this issue solved. Other PDF viewers don't show the issue, so apparently the flag is not that important. - Lauri - To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
