Re: Beamer, transparent background colour

On Sep 29, 6:29 pm, Sebastian Szwarc <beyond...@xxxxxxx> wrote:
Kjell could you explain a little this code:

\defbeamertemplate{background}{image}[1][]{
\pgfdeclareimage[interpolate=true,
height=.8\textheight]{background image}{#1}
\begin{pgfpicture}{0cm}{0cm}{\the\paperwidth}{-\the\paperheight}
\pgfputat{\pgfxy(6.4,-4.8)}
{\pgfbox[center,center]%
{\pgfuseimage{background image}}}
\end{pgfpicture}%
\setbeamertemplate{background}[image][slika3]

I dont see this intuitive...{image} is command or just name of the image?
and why to use:
\setbeamertemplate{background}[image][slika3] if earlier there is only
one paramter [1][]

Your question should be directed to Zarko, but here it goes:

Zarko has used the \defbeamertemplate command to override the
background template. The \defbeamertemplate is powerful and highly
configurable. What Zarko does in this case is to first assign a
predefined option called 'image' to the background template. The
element takes one parameter, no default value is specified:

\defbeamertemplate{template name}{predefined option}[#arguments]
[default value]{template contents}

So when he wants to use this template he uses:
\setbeamertemplate{template name}[predefined option][argument]

I don't know if this makes much sense. I recommend reading chapter
'16.3.2 Using Beamer’s Templates' in the Beamer manual carefully to
understand all the details. 'image' is in this case just a name used
to trigger a specific variant of the background template. Beamer
defines a few variants of the background template, like for instance
grid. You invoke it using:

\setbeamertemplate{background}[grid]

You can even give it a parameter:

\setbeamertemplate{background}[grid][step=1cm]

- Kjell Magne Fauske

.