如何设置 beamer 中帧的背景图像的透明度?我已经尝试过了。
\documentclass[bigger]{beamer}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
%Global Background must be put in preamble
\usebackgroundtemplate%
{%
\includegraphics[width=\paperwidth,height=\paperheight]{Doc8}%
}
\begin{document}
\begin{frame}{Introduction}
\begin{itemize}
\item 1
\item 2
\item 3
\end{itemize}
\end{frame}
% Local background must be enclosed by curly braces for grouping.
{
\usebackgroundtemplate{\includegraphics[width=\paperwidth]{GPGC}}%
\begin{frame}{Kitten}
\begin{itemize}
\item 1
\item 2
\item 3
\end{itemize}
\end{frame}
}
\begin{frame}{Summary}
\begin{itemize}
\item 1
\item 2
\item 3
\end{itemize}
\end{frame}
\end{document}