如何在一张图片上随机放置问号？

Question

我想在一张图片上以随机大小和随机旋转角度放置几个问号，我做不到，如有任何建议我将不胜感激。

\documentclass[tikz,border=5pt]{article}
    \usepackage{graphicx}
    \usepackage{picture}
    \usepackage{eso-pic}
    \usepackage[first=1,last=1000]{lcg}
    \usepackage{calc} 
    \begin{document}
    \pagestyle{empty}
    \centering
    \includegraphics{librarys}
    \def\wordlist{\textquestiondown,\textquestiondown,\textquestiondown,\textquestiondown,\textquestiondown}
      \makeatletter                        
    \newlength{\randx} \newlength{\randy} % Coordinates of the next word should be saved as random generator produces one number
    \AddToShipoutPictureBG*{
      \@for\TempVar:=\wordlist\do{%
        \rand \setlength{\randx}{\paperwidth*\ratio{\value{rand}mm}{1000mm}}  % Set random x position
        \rand \setlength{\randy}{\paperheight*\ratio{\value{rand}mm}{1000mm}} % Set random y position
        \rand  % Generate new random to use as angle
        \put(\randx,\randy){\makebox(0,0)[c]{\rotatebox{\value{rand}}{\TempVar}}}% Show next word
      }
    } 



    \end{document} 

Answer 1

以下是使用 tikz 的示例。请注意，由于记住图片缓存内容，您可能需要删除辅助文件以强制其重新定位。

\documentclass[a4paper]{article}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\thispagestyle{empty}
\begin{tikzpicture}
   \fill[blue] (0,0) circle (5);
\end{tikzpicture}
\begin{tikzpicture}[remember picture,overlay]
  % I'll just use letters
  \foreach \letter in {A,B,C,D,E}{
    \pgfmathsetmacro\randA{random()}
    \coordinate (A) at ($(current page.north west)!\randA!(current page.north east)$);
    \pgfmathsetmacro\randB{random()}
    \coordinate (B) at ($(current page.north west)!\randB!(current page.south west)$);
    \coordinate (C) at ($(A |- B)$);
    \typeout{A: \randA; B: \randB} 
    \node at (C) {\Huge \letter};
  }
\end{tikzpicture}
\end{document}