From: Jeremias Maerki Date: Mon, 24 Jan 2011 09:55:52 +0000 (+0000) Subject: FAQ entry for anti-aliasing artifacts in Adobe Acrobat. X-Git-Tag: fop-1_1rc1old~352 X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=a136c6faa5991fbfc60c64998da50e26a8f6660c;p=xmlgraphics-fop.git FAQ entry for anti-aliasing artifacts in Adobe Acrobat. git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1062710 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/src/documentation/content/xdocs/faq.xml b/src/documentation/content/xdocs/faq.xml index c2f6cb7ca..2fd6e16ca 100644 --- a/src/documentation/content/xdocs/faq.xml +++ b/src/documentation/content/xdocs/faq.xml @@ -1016,6 +1016,46 @@ Can I control this?

+ + How can I get rid of strange single-pixel lines inside table borders or between table cells in Adobe Acrobat? + +

+ Since Apache FOP supports the collapsed border model, every border segment consists + of two separate shapes. This is due to the fact that each side of the border + segment can have a different color. Now, Adobe Acrobat may display thin (1 pixel wide) + lines inside the border segment or sometimes even between to adjacent + colored rectangles making up the background of a block or table cell. + This effect is due to the way Adobe Acrobat does anti-aliasing. Adobe's algorithm + seems to cause these artifacts. Other PDF viewers don't have that problem. Or at least + we haven't had any reports in that direction. +

+

+ First of all, these artifacts do not appear in print since no anti-aliasing is done + by Adobe Acrobat in this case (except maybe if you tell Acrobat to print the page + as a bitmap in which case Adobe fully composes the page itself). So, if the artifacts appear + on screen, it doesn't mean they have to appear in print, too. +

+

+ To get rid of the artifacts, you can call up the "Preferences" dialog of + Adobe Acrobat and select the tab "Page display". Enabling "Enhance thin lines" + may help in some situations. Otherwise, you can disable "Smooth line art". + You may have to disable "Use 2D graphics acceleration", too, so you can disable + "Smooth line art" in the first place. +

+

+ Here an example of how the effect can look like (left: anti-aliasing on, right: anti-aliasing off): +

+
+

+ Unfortunately, it is not possible to control the above settings from within the PDF file. + The user has to change these settings himself. Improving FOP to avoid this kind of problem + would be possible although rather hard to achieve because we'd need to add a considerable + amount of code to combine the various line segments. Something like that has been tried already + years ago showing that this is a tricky task. Also, the improvement may not justify the amount + of effort required. +

+ + IEx specific stuff diff --git a/src/documentation/resources/images/acrobat-anti-aliasing-artifacts.png b/src/documentation/resources/images/acrobat-anti-aliasing-artifacts.png new file mode 100644 index 000000000..db9c23a2a Binary files /dev/null and b/src/documentation/resources/images/acrobat-anti-aliasing-artifacts.png differ diff --git a/src/documentation/resources/images/anti-aliasing-artifacts-demo.fo b/src/documentation/resources/images/anti-aliasing-artifacts-demo.fo new file mode 100644 index 000000000..5917e80e0 --- /dev/null +++ b/src/documentation/resources/images/anti-aliasing-artifacts-demo.fo @@ -0,0 +1,57 @@ + + + + + + + + + + + + + + + + Cell 1/1 + + + Cell 2/1 + + + + + Cell 1/2 + + + Cell 2/2 + + + + + + + + + + + + Cell 1/1 + + + Cell 2/1 + + + + + Cell 1/2 + + + Cell 2/2 + + + + + + +