EDIT-2 see code below. I fixed it, and it works. My question is whether reledpar may help with what I need. This is to publish - face to face - scans of handwritten letters and their trascripts, for about 100 scans. Code below does not help because it seems I need to insert some dummy text on the leftside, and the final output is: a page with the scan, leftside page with dummy text, rightside page. (scan and dummy text goes within the same page if I downsize scan, but that is not good enough for my present)
\documentclass[titlepage,a4paper,12pt]{article}
\usepackage[OT2,T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage{graphicx}
\usepackage[american,russian,italian]{babel}
\usepackage[babel,italian=guillemets]{csquotes}
\usepackage{reledmac}
\usepackage{reledpar}
\begin{document}
\begin{pages}
\begin{Leftside}
\beginnumbering
\pstart[
{\begin{figure}
\centering
\includegraphics[scale=.25]{test/001.jpg}
\end{figure}} <--- I need to {} code within [], don't I?
] DUMMY TEXT
\endnumbering
\end{Leftside}
\begin{Rightside}
\beginnumbering
\pstart
\input{test/001.tex }
\pend
\endnumbering
\end{Rightside}
\end{pages}
\Pages
\begin{pages}
\begin{Leftside}
\beginnumbering
\pstart[
{\begin{figure}
\centering
\includegraphics[scale=.25]{test/002.jpg}
\end{figure}}
] DUMMY TEXT
\pend
\endnumbering
\end{Leftside}
\begin{Rightside}
\beginnumbering
\pstart
\input{test/002.tex }
\pend
\endnumbering
\end{Rightside}
\end{pages}
\Pages
\end{document}
ps also, I do not need to show line numbers, is there a option to hide them?