Image conversion fails when using `--build-dir`

[julienlabbe]

The image conversion fails with --build-dir: the conversion program can't find the image files.

Example:

\documentclass{article}
\usepackage{graphicx}
\begin{document}
This is a test.
\includegraphics{example-image.pdf}
\end{document}

Run with:

cp $(kpsewhich example-image.pdf) . 
make4ht --loglevel debug --build-dir html test.tex

This gives

System call: rungs -q -dNOPAUSE -dBATCH -dusecropbox -sDEVICE=pngalpha -r300  -sOutputFile="example-image-.png" "example-image.pdf" 
--- Warning --- System return: 256

[michal-h21]

This issue is complicated to solve automatically, because the command for the PDF conversion is configured on the TeX side, which doesn't know about the build dir. You can change the conversion command using \Configure{PdfConvert}:

\Preamble{xhtml}
\catcode`\:=11
\makeatletter
\Configure{PdfConvert}{png}{"rungs -q -dNOPAUSE -dBATCH -dusecropbox -sDEVICE=pngalpha -r\gr:density\space \ifx\Gin@page\@empty\else -dFirstPage="\Gin@page"  -dLastPage="\Gin@page"\fi\space -sOutputFile="\Gin@base-\Gin@page.\a:PdfConvert" "../\Gin@base.pdf" "}
\makeatother
\catcode`\:=12
\Css{img { max-width: 100\%; height: auto; } }
\begin{document}
\EndPreamble

This is basically just a copy from html4.4ht, I've just changed the PDF file path passed to rungs to include .., as the compilation happens in the html directory, but the PDF file is in a parent directory.

A better solution may be to convert the PDF file to PNG or SVG manually and use the \includegraphics command without extension. LaTeX will then pick the best version of the file.