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| -rw-r--r-- | src/documentation/content/xdocs/faq.xml | 40 | ||||
| -rw-r--r-- | src/documentation/resources/images/acrobat-anti-aliasing-artifacts.png | bin | 0 -> 8128 bytes | |||
| -rw-r--r-- | src/documentation/resources/images/anti-aliasing-artifacts-demo.fo | 57 |
3 files changed, 97 insertions, 0 deletions
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?</question> </p> </answer> </faq> + <faq id="acrobat-anti-aliasing"> + <question>How can I get rid of strange single-pixel lines inside table borders or between table cells in Adobe Acrobat?</question> + <answer> + <p> + 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. + </p> + <p> + 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. + </p> + <p> + 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. + </p> + <p> + Here an example of how the effect can look like (left: anti-aliasing on, right: anti-aliasing off): + </p> + <figure src="images/acrobat-anti-aliasing-artifacts.png" alt="Left: anti-aliasing on, Right: off"/> + <p> + 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. + </p> + </answer> + </faq> </part> <part id="part-iex"> <title>IEx specific stuff</title> diff --git a/src/documentation/resources/images/acrobat-anti-aliasing-artifacts.png b/src/documentation/resources/images/acrobat-anti-aliasing-artifacts.png Binary files differnew file mode 100644 index 000000000..db9c23a2a --- /dev/null +++ b/src/documentation/resources/images/acrobat-anti-aliasing-artifacts.png 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 @@ +<?xml version="1.0" encoding="UTF-8"?> +<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format"> + <fo:layout-master-set> + <fo:simple-page-master master-name="page" page-height="3.1cm" page-width="6cm" margin="2mm"> + <fo:region-body/> + </fo:simple-page-master> + </fo:layout-master-set> + <fo:page-sequence master-reference="page"> + <fo:flow flow-name="xsl-region-body"> + <fo:table table-layout="fixed" inline-progression-dimension="100%"> + <fo:table-column column-width="50%"/> + <fo:table-column column-width="50%"/> + <fo:table-body> + <fo:table-row> + <fo:table-cell border="solid 2mm darkblue"> + <fo:block>Cell 1/1</fo:block> + </fo:table-cell> + <fo:table-cell border="solid 2mm darkblue"> + <fo:block>Cell 2/1</fo:block> + </fo:table-cell> + </fo:table-row> + <fo:table-row> + <fo:table-cell border="solid 2mm darkblue"> + <fo:block>Cell 1/2</fo:block> + </fo:table-cell> + <fo:table-cell border="solid 2mm darkblue"> + <fo:block>Cell 2/2</fo:block> + </fo:table-cell> + </fo:table-row> + </fo:table-body> + </fo:table> + + <fo:table table-layout="fixed" inline-progression-dimension="100%" space-before="2mm"> + <fo:table-column column-width="50%"/> + <fo:table-column column-width="50%"/> + <fo:table-body color="white"> + <fo:table-row> + <fo:table-cell background-color="darkgreen"> + <fo:block>Cell 1/1</fo:block> + </fo:table-cell> + <fo:table-cell background-color="darkgreen"> + <fo:block>Cell 2/1</fo:block> + </fo:table-cell> + </fo:table-row> + <fo:table-row> + <fo:table-cell background-color="darkgreen"> + <fo:block>Cell 1/2</fo:block> + </fo:table-cell> + <fo:table-cell background-color="darkgreen"> + <fo:block>Cell 2/2</fo:block> + </fo:table-cell> + </fo:table-row> + </fo:table-body> + </fo:table> + </fo:flow> + </fo:page-sequence> +</fo:root> |
