為圖像添加標題和來源，保持標題居中，來源與圖像左對齊

Question

我有一個相當令人討厭的論文指南需要遵循，不幸的是我無法用我的 LATEX 技能來滿足它。

我需要將圖形的標題居中，並且該標題可能是多行文字。我還需要添加來源，但來源必須位於標題上方。對我來說真正困難的部分是滿足來源必須與圖像對齊的規則，在左側（而不是頁面的邊緣）。

另外，如果不太麻煩的話，原始碼和標題之間的垂直間距應該是 6pt（MS Word 單位）。

下面的程式碼是我嘗試遵循準則的嘗試。第二張圖片只是為了檢查標題編號是否一致。

\documentclass{article}

\usepackage{graphicx}
\usepackage{float}

\usepackage[justification=centering]{caption}

\newcommand*{\captionsource}[2]{%
    
    \captionsetup{labelformat=empty}
    \caption{Source: {#2}}
    \addtocounter{figure}{-1}
    \captionsetup{labelformat=original}
    \caption{ {#1} }
} %


\begin{document}
    \begin{figure}[H]
        \centering
        \includegraphics[scale=0.3]{eta-carinae.jpg}
        \captionsource{Caption text of the image, with more than one line of text, centered, I'll just be filling with text until it overflows to next line.}{A source with ref, cite or free text.}
        \label{Source with cite.}
    \end{figure}


    \begin{figure}[H]
    \centering
    \includegraphics[scale=0.5]{crab-nebula.jpg}
    \captionsource{Caption text of the image, with more than one line of text, centered, I'll just be filling with text until it overflows to next line.}{A source with ref, cite or free text.}
    \label{Source with cite.}
\end{figure}

\end{document}

% Image sources:    
% Eta Carinae https://pt.wikipedia.org/wiki/Eta_Carinae#/media/Ficheiro:EtaCarinae.jpg
% Crab Nebula:  
% https://en.wikipedia.org/wiki/File:Crab_Nebula.jpg

這是所需的輸出：

Answer 1

我假設來源標題始終與圖形寬度相同且左對齊。我寧願不使用兩個\caption命令，它會增加你的數字列表。這是將圖形和來源放在\parbox與圖形相同寬度的解決方案中。

\documentclass{article}

\usepackage{graphicx}
\usepackage{float}

\usepackage[justification=centering,skip=6pt]{caption}

\newcommand{\graphicsandsource}[2]{%
\sbox0{#1}\parbox{\wd0}{#1\par Source: #2}
}


\begin{document}
    \begin{figure}[H]
        \centering\graphicsandsource{\includegraphics[scale=0.3]{example-image-a}}{A source with ref, cite or free text.} 
        \caption{Caption text of the image, with more than one line of text, centered, I'll just be filling with text until it overflows to next line.}
        \label{Source with cite1.}
    \end{figure}


    \begin{figure}[H]
    \centering\graphicsandsource{\includegraphics[scale=0.5]{example-image-b}}{A source with ref, cite or free text.} 
    \caption{Caption text of the image, with more than one line of text, centered, I'll just be filling with text until it overflows to next line.}
    \label{Source with cite2.}
\end{figure}

\end{document}