子标题标签位置 - 双面报告的意外行为

Question

我需要将子图标签放置在其各自图形的左上角。对于普通报告，我可以很好地做到这一点，但是如果我更改为双面报告，偶数页上的标签就会不正确。在偶数页上，标签不会移到正确的位置，并且子图会偏移（前提是它们的大小不同）。我不确定从这里开始该怎么做才能解决这个问题。

这是 MWE，任何帮助或见解都将非常有用：

\documentclass[12pt, twoside]{report}

\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}

\usepackage{lipsum}

\captionsetup[subfigure]{
    singlelinecheck = false,
    justification = raggedright,
    margin = {-3ex, 0ex},
}

\begin{document}

%
\begin{figure}[tbp]
    \centering
    \begin{subfigure}[t]{0.4\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-a}
    \end{subfigure}
    \hspace{3ex}
    \begin{subfigure}[t]{0.28\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-b}
    \end{subfigure}
    \caption{Labels in correct position.}
\end{figure}
%

\lipsum[1-3]

%
\begin{figure}[tbp]
    \centering
    \begin{subfigure}[t]{0.4\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-a}
    \end{subfigure}
    \hspace{3ex}
    \begin{subfigure}[t]{0.28\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-b}
    \end{subfigure}
    \caption{Labels in incorrect position, and figures offset.}
\end{figure}
%

\lipsum[4-5]

%
\begin{figure}[tbp]
    \centering
    \begin{subfigure}[t]{0.4\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-a}
    \end{subfigure}
    \hspace{3ex}
    \begin{subfigure}[t]{0.28\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-b}
    \end{subfigure}
    \caption{Labels back in correct position.}
\end{figure}
%

\end{document}

Answer 1

根据caption包裹文件 Page.11, '在双面文档中，偶数页的左右边距会交换。为了防止这种情况，您可以另外指定选项 oneside，例如 \captionsetup{margin= {0pt,10pt},oneside}'。因此，正确的示例是：

\documentclass[12pt, twoside]{report}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{lipsum}
\captionsetup[subfigure]{
    singlelinecheck = false,
    justification = raggedright,
    margin = {-3ex, 0ex},
    oneside
}
\usepackage[showframe]{geometry}

\begin{document}
%
\begin{figure}[t]
    \centering
    \begin{subfigure}[t]{0.4\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-a}
    \end{subfigure}
    \hspace{3ex}
    \begin{subfigure}[t]{0.28\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-b}
    \end{subfigure}
    \caption{Labels in correct position.}
\end{figure}
%
\lipsum[1-3]
%
\begin{figure}[t]
    \centering
    \begin{subfigure}[t]{0.4\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-a}
    \end{subfigure}
    \hspace{3ex}
    \begin{subfigure}[t]{0.28\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-b}
    \end{subfigure}
    \caption{Labels in incorrect position, and figures offset.}
\end{figure}
%
\lipsum[4-5]
%
\begin{figure}[t]
    \centering
    \begin{subfigure}[t]{0.4\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-a}
    \end{subfigure}
    \hspace{3ex}
    \begin{subfigure}[t]{0.28\linewidth}
        \subcaption{}
        \includegraphics[width=\linewidth]{example-image-b}
    \end{subfigure}
    \caption{Labels back in correct position.}
\end{figure}
%
\end{document}