是否可以在 beamer 中的文本框框架中创建备用覆盖背景？

Question

这是示例代码。但基本上我的演示文稿中有一个自定义背景，但文本的某些部分偶尔会干扰背景的颜色。所以我想我在 mdframed 环境中制作另一个叠加背景来解决这个问题。我认为这样的背景会是原始背景的模糊背景。这在 LaTeX 中可行吗，还是我必须在 Photoshop 之类的软件中执行此操作？

\documentclass{beamer}
\mode<presentation>

\usepackage{graphicx} 
\graphicspath{ {images/} }
\usebackgroundtemplate{
  \includegraphics[width=6in,height=4in]{Custom BackgroundName}} 
  \beamertemplatenavigationsymbolsempty
\begin{document}

  \begin{frame}
   So right here is the frame and text with a custom background. Now I want to create a textbox because my textcolor interfers with certain parts of my custom background. So I thought the easiest way out would be to create a smudged overlayered background in a mdframed environcment such as

   \begin{mdframed}

    Text here but in this environment you can read clearer, but the mdframed environment introduces a white background. I want this to be something else, like a smudged background. Also the environment should blend in *smoothly* with the custom background.

    \end{mdframed}


   \end{frame}

\end{document}

Answer 1

如果你正在寻找一些半透明的块，你可以这样做

\documentclass{beamer}
\usetheme{Berlin}

\usebackgroundtemplate{\includegraphics[width=\paperwidth,height=\paperheight]{example-grid-100x100bp}}

\addtobeamertemplate{block begin}{%
    \pgfsetfillopacity{0.65}%
}{
    \pgfsetfillopacity{1}%
}


\begin{document}
  \begin{frame}
    \begin{block}{Test}
            Bla
    \end{block}
  \end{frame}
\end{document}

如果您正在寻找一种方法来模糊背景图像，那么最好使用像这样的图像处理工具gimp。