IMAGE - PDF - A4

Le Basque
Posts: 147
Joined: Sat Oct 19, 2013 8:21 am

IMAGE - PDF - A4

Post by Le Basque » Mon Oct 28, 2013 2:45 pm

Hi,
I had a question about image management: when you created a publication on A4 pdf , which is the maximum size for an image is displayed correctly in the text ?

We can not know ... how max width must retouch images for this size matches all output formats ...

Thank you

Best regards

sorin_ristache
Posts: 4144
Joined: Fri Mar 28, 2003 2:12 pm

Re: IMAGE - PDF - A4

Post by sorin_ristache » Mon Oct 28, 2013 4:24 pm

Hello,

For the A4 page format of the PDF output the maximum width for an image is about 800 pixels for a 72 DPI output resolution of the FO processor. For example Oxygen comes with Apache FOP and sets an output resolution of 120 DPI and in this case the maximum width is about 1,000 pixels. You can change the resolution in the FOP config file located at: [Oxygen-install-dir]/lib/fop.xconf.

If you use a different FO processor which you set in the Oxygen transformation dialog box you have to check first the output resolution in the config file of your FO processor. For example the default resolution of RenderX XEP is 1440 for which the maximum width that will fit into an A4 page is about 1,000 pixels.

It is best to keep the width of all images under 1,000 pixels so that you can use the same image in all output formats. If your image has a larger width than 1,000 pixels and you want to leave it as it is for other output formats (for example XHTML or Webhelp) but scale it down for PDF output (for example scale the image from 1,500 pixels down to 1,000 pixels) you can duplicate and profile the image in the XML document, one profile for each output, as in the following Docbook example:

Code: Select all

        <figure xml:id="image_ID_webhelp"  condition="webhelp">
<title>Image title here</title>
<mediaobject>
<imageobject>
<imagedata fileref="img/my_image.png"/>
</imageobject>
</mediaobject>
</figure>
<figure xml:id="image_ID_pdf" condition="pdf">
<title>Image title here</title>
<mediaobject>
<imageobject>
<imagedata fileref="img/my_image.png" scale="60"/>
</imageobject>
</mediaobject>
</figure>

In this case you have to set the attribute profiling.condition in the Docbook transformation to the value webhelp for the Webhelp output and to the value pdf for the PDF output. The same image file is used for both output formats (img/my_image.png) but the PDF transformation will shrink the image to fit in the 1,000-pixel width limit.


Regards,
Sorin

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