添加阴影图像边框的简单解决方案

Question

我想制作阴影图像边框。我当前的解决方案是使用\shadowbox：

 \documentclass[12pt]{article}
 \usepackage{tikz}
 \usepackage{fancybox, graphicx}  

 \begin{document}
    \shadowsize=1mm
    \color{blue}
    \shadowbox{\fboxsep=3mm\fcolorbox{white}{white}{\includegraphics[width=12cm,height=8cm,keepaspectratio]{example-image-a}}}
\end{document}

因此 1) 必须有一个白色边框 2) 投射阴影。但这会创建一个非常“简单”的实心阴影：

我想实现更加“模糊的效果”。

基于这答案我写了类似这样的内容：

\documentclass[12pt]{article}
\usepackage{tikz}
\usepackage[skins]{tcolorbox}
\usepackage{fancybox, graphicx}

\begin{document}
  \begin{center}
      \begin{tcolorbox}[enhanced,width=12cm,height=8cm, center upper,
          fontupper=\large\bfseries,drop fuzzy shadow southeast,
          boxrule=0.4pt,sharp corners,colframe=yellow!80!white,colback=white!10]

      \includegraphics[width=12cm,height=7.9cm,keepaspectratio]{example-image-a}
      \end{tcolorbox}
      \end{center}
\end{document}

但正如您所看到的，我需要这个颜色框根据我的图像进行缩放（最大尺寸为 8x12cm，保持纵横比）。

我看到一些过于复杂的答案并应用了一些规则，但我确实相信一定有一个更简单的解决方案。

此外 - 上述解决方案实际上可以将阴影投射到世界的 4 个侧面，而不仅仅是southeast等等？

Answer 1

\tcolorbox正在使用\linewidth或指定的尺寸width和，但height考虑到内部内容，这可能是错误的。

\tcbox根据内部内容改变尺寸并适当缩放。

我已经定义了\whiteshadowbox一些选项，定心是通过before和after键完成的。

\documentclass[12pt]{article}
\usepackage[skins]{tcolorbox}

\newtcbox{\whiteshadowbox}[1][]{%
  enhanced, 
  center upper,
  fontupper=\large\bfseries,
  drop fuzzy shadow southeast,
  boxrule=0.4pt,
  sharp corners,
  colframe=blue,
  colback=white!10,
  before={\begin{center}},
    after={\end{center}},
  #1%
}

\begin{document}
  \whiteshadowbox{%
    \includegraphics[width=12cm,height=7.9cm,keepaspectratio]{example-image-a}
  }

  \whiteshadowbox[colback=green]{%
    \includegraphics[width=5cm,height=6cm,keepaspectratio]{example-image-a}
  }
\end{document}

使用halo选项更新

\documentclass[12pt]{article}
\usepackage[skins]{tcolorbox}

\newtcbox{\whiteshadowbox}[1][]{%
  enhanced, 
  center upper,
  fontupper=\large\bfseries,
  fuzzy halo={0.9mm with gray},
%  drop fuzzy shadow southeast,
  boxrule=0.4pt,
  sharp corners,
  colframe=blue,
  colback=white!10,
  before={\begin{center}},
    after={\end{center}},
  #1%
}

\begin{document}
  \whiteshadowbox{%
    \includegraphics[width=12cm,height=7.9cm,keepaspectratio]{example-image-a}
  }

  \whiteshadowbox[colback=green]{%
    \includegraphics[width=5cm,height=6cm,keepaspectratio]{example-image-a}
  }
\end{document}

使用size=tight和boxsep=1cm设置

\documentclass[12pt]{article}
\usepackage[skins]{tcolorbox}

\tcbset{
  halobox/.style={
    enhanced,
    center upper,
    fontupper=\large\bfseries,
    size=tight,
    boxsep=1cm,
    fuzzy halo={0.9mm with gray},
    boxrule=0.4pt,
    sharp corners,
    colframe=blue,
    colback=white!10,
    before={\begin{center}},
      after={\end{center}}}
  }

\newtcbox{\whiteshadowbox}[1][]{%
  halobox,
  #1%
}

\begin{document}
  \whiteshadowbox{%
    \includegraphics[width=12cm,height=7.9cm,keepaspectratio]{example-image-a}
  }

  \whiteshadowbox[colback=green]{%
    \includegraphics[width=5cm,height=6cm,keepaspectratio]{example-image-a}
  }
\end{document}

Answer 2

该pstricks模块非常简单pst-blur：

\documentclass[12pt, svgnames]{article}
\usepackage{graphicx}
\usepackage{pst-blur} 
%\usepackage{auto-pst-pdf}% to compile with pdflatex --enable-write18 (MiKTeX) or pdflatex --shell-escape (TeXLive, MacTeX)

 \begin{document} 

\begin{pspicture}
 \psframebox[linecolor = RoyalBlue, framesep = 4mm, shadow, blur, shadowcolor = RoyalBlue, shadowsize = 1.5mm ]{%
 \includegraphics[width = 12cm, height = 8cm, keepaspectratio]{example-image-a}}
\end{pspicture}

\end{document}