When producing screendumps, the spectacle KDE screenshot program makes
screenshots at 300 dpi. 

Do not change anything and export to web-<filename>.png

In the DocBook source, for role "html", do not scale anyting.

Then scale to the proper dimensions (typically 120 mm)  specifying 300x300
pix/inch export to "print-<filename>" and then for the role "fo", scale="100" is good.

Example:


				<figure xml:id="fig_minexpert-tic-chrom-wnd-two-traces">

					<title>The total ion current (TIC) chromatogram window</title>

					<mediaobject>

						<imageobject role="fo">
							<imagedata fileref="print-minexpert-tic-chrom-wnd.png" format="PNG" scale="100"/>
						</imageobject>

						<imageobject role="html">
							<imagedata fileref="web-minexpert-tic-chrom-wnd.png" format="PNG" scale="100"/>
						</imageobject>

						<caption><para>As many traces as necessary can be shown in the window.
								Each plot has its own set of markers.</para></caption>

					</mediaobject>

				</figure>


