Increase equation resolution in TeX4ht using accessible images or typeset text

Question

When TeX4ht compiles my latex code it generates a png of my equation and includes this in the html file. Until a better alternative for this comes along I am quite happy with this way of managing/presenting my equations.

This is a collaborative project and I am working with some very anti-latex and anti software people, so I generate html files that they can edit. By ensuring complete compatibility between the html file and pdf generation everyone remains happy. I would however prefer to have a higher resolution image that my collaborators can read without getting frustrated with the document quality.

Approaches I have investigated and been unsuccessful with:

1. An excellent explanation that I apologize for missing during my initial week spent trying to solve this issue here LaTeX --> (X)HTML with tex4ht: bad quality images of equations uses a conversion of eps to svg.

Unfortunately eps are not file extensions that my collaborators can open, nor is it something they are willing or even capable to upgrade software to work with. So This solution is not my preferred approach unless the final image type is not an eps.

I am sure I am not doing something quite right with the implementation of this as on our work computers I am left only with the eps file, no png or svg are created, and browser/editable integration of the eps is hit or miss. If memory serves, the mentioned convert program is part of imagemagick which we do have installed, so I am at a loss why the svg or png creation is absent using the custom cfg file mentioned in the solution. Maybe this should be the question itself which I believe is completely distinct albeit related to the question that this is currently marked as a duplicate for.

2. It might be neat to use a completely different approach maybe using http://latex2html5.com which honestly I haven't even been able to figure out how to compile their examples - but I feel it holds promise for the issue I described above if I can figure out what it is supposed to do and how to do it (unless this tool is the best option to solve my problem, this is a question for another day which I will post and edit this question to remove this aspect to prevent duplication). One aspect of this approach that would interest me, is the appearance that this is not a picture, but formatted text...

Here is my MWE.

\documentclass{report}  
\usepackage{amsmath}
\begin{document}
        \begin{equation}
            \text{C~=~}{\frac{a}{b}}
        \end{equation}
\end{document}

Answer 1

There are several approaches described in the linked answer. Route from eps to output formats is the default way tex4ht deals with generated images. You shouldn't get eps images as final format, it is always converted to something which can be displayed with a browser.

another way is to use some dvi to image converter such as dvipng or dvisvgm. To avoid need to modify the .env file, which was in depth described in the linked answer, I will show solution using make4ht.

create a build file, named as texfilename + .mk4 suffix:

Make:htlatex{}
Make:image("png$","dvipng -bg Transparent -T tight -D151 --freetype -o     ${output}  -pp ${page} ${source}")
Make:image("svg$","dvisvgm -n -p ${page} -c 1.4,1.4 -s ${source} > ${output}")

this build file calls htlatex only once, as you don't use hyperlinks and references, which need more htlatex runs.

Make:image declaration are used depending on the used image output (which can be configured). for png output, dvipng is used, for svg, it is dvisvgm. you can set the image resolution with -D option for dvipng and -c option for dvisvgm, you need to try some values, which one will fit your text best.

for png output, compile with

make4ht filename

the result:

to compile to svg, you need to configure image output, for example with such config file., hello.cfg:

\Preamble{xhtml}
\Configure{Picture}{.svg}
\begin{document}
\EndPreamble

compile now with

make4ht -c hello filename

and the output:

you may need to read man pages for dvipng or dvisvgm and play with parameters to suit your needs