pdflatex：使用 includepdfmerge(pdf-pages) 生成的 pdf 文件大小比 includegraphics 小得多

Question 1

似乎将 pdf 存储在临时框中一次就足以触发字体优化。只有使用 pdflatex 时才需要它，lualatex 默认会这样做。

\documentclass{article}
\usepackage{graphicx}
\pagestyle{empty}
\makeatletter
\setbox\@tempboxa=\hbox{\includegraphics{example-image-a4-numbered}}% font is included only once
\makeatother
\begin{document}

\includegraphics[width=\textwidth,keepaspectratio,page=1]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=2]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=3]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=4]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=5]{example-image-a4-numbered}%
\end{document}

Answer

似乎将 pdf 存储在临时框中一次就足以触发字体优化。只有使用 pdflatex 时才需要它，lualatex 默认会这样做。

\documentclass{article}
\usepackage{graphicx}
\pagestyle{empty}
\makeatletter
\setbox\@tempboxa=\hbox{\includegraphics{example-image-a4-numbered}}% font is included only once
\makeatother
\begin{document}

\includegraphics[width=\textwidth,keepaspectratio,page=1]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=2]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=3]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=4]{example-image-a4-numbered}%
\newpage
\includegraphics[width=\textwidth,keepaspectratio,page=5]{example-image-a4-numbered}%
\end{document}

Question 2

回答第 1 部分：为什么仅使用 includegraphics 时文件大小会很大

这是由于多次嵌入字体

仅使用includegraphics

$ pdffonts test_includegraphics.pdf 
name                                 type              encoding         emb sub uni object ID
------------------------------------ ----------------- ---------------- --- --- --- ---------
ABCDEE+ScaGoudy                      TrueType          WinAnsi          yes yes no       9  0
ABCDEE+ScaGoudy                      TrueType          WinAnsi          yes yes no      19  0
ABCDEE+ScaGoudy                      TrueType          WinAnsi          yes yes no      31  0
ABCDEE+ScaGoudy                      TrueType          WinAnsi          yes yes no      41  0
ABCDEE+ScaGoudy                      TrueType          WinAnsi          yes yes no      51  0

仅使用以下方式制作的文件includepdfmerge

$ pdffonts test_includepdf.pdf 
name                                 type              encoding         emb sub uni object ID
------------------------------------ ----------------- ---------------- --- --- --- ---------
ABCDEE+ScaGoudy                      TrueType          WinAnsi          yes yes no      12  0

使用第一页制作的文件includepdfmerge，其余部分使用includegraphics

$ pdffonts test_mix.pdf       
name                                 type              encoding         emb sub uni object ID
------------------------------------ ----------------- ---------------- --- --- --- ---------
ABCDEE+ScaGoudy                      TrueType          WinAnsi          yes yes no      15  0

正如所见，5 times当我仅使用includegraphics其他两种情况时，字体才会嵌入once

第 2 部分未找到答案：如何避免

But now the question is how can we avoid font getting embedded mutliple times when made using only includegraphics

我发现了类似的问题：

包含使用独立创建的图形时，相同的字体嵌入两次

其中一个答案说使用 latex 是不可能的。唯一的方法是稍后使用pdfsizeopt https://tex.stackexchange.com/a/83709/221200

还尝试了建议的解决方案\pdfinclusioncopyfonts=0，但它不起作用，或者字体在 pdflatex 中多次嵌入

Answer