TeX4ht and Calibre

Question

I try to use TeX4ht and Calibre to create an ebook that I can read with an iPad. I use the following command: htlatex file.tex "xhtml, jsmath""-cmozhtf". The result with Calibre is correct except for some mathematical formulas.

For example, the equation : $ x ^ 2 - 6x +6 = 0$ , we obtain : {x} ^ {2} - 6x + 6 = 0.

To : \ [B (x) =-x ^ 2 + 60x-500, \ quad \ textrm {where $ x $ belongs to the interval $ \ left [0 \, 60 \ right] $.} \] we obtain : B (x) = - {x} ^ {2} + 60x - 500, \ quad \ textrm {where $ x $ belongs to the interval $ \ left [0 \ kern 1.81503pt, 60 \ right] $ .}

For : $ T_1 $, we obtain : {T} _ {1}.

---

First question :

Why, in this code, formulas framed dollars are not transformed into images (and the record is best !)?

\documentclass[a4paper,11pt]{article} 

\usepackage[utf8]{inputenc} 
\usepackage{amsmath,amsfonts} 

\begin{document} 

\section*{Sample French Text}

Lucie, étudiante des États-Unis, vient d'arriver à Charles de
Gaulle, l'aéroport qui accueille chaque jour à Paris, 1 million de
visiteurs. Paris. Enfin. Ça a toujours été le rêve de Lucie : vivre
dans la Ville lumière, la ville des beaux arts, du quartier latin, du
vin, et qui sait, peut-être la ville d'une petite histoire d'amour.

\section*{Math Part}
Numbered equation:
\begin{equation} 
P_{r-j}= 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{equation} 
Un-numbered equation:
\begin{equation*} 
P_{r-j}= 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{equation*} 
Inline equation: 
$ x ^ 2 - 6x +6 = 0$ and $B (x) =-x ^ 2 + 60x-500, \quad
\textrm{where $ x $ belongs to the interval $ [0 \, ; 60 ] $.}$ 

Eqnarray
\begin{eqnarray} 
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} \\
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{eqnarray} 
Starred eqnarray
\begin{eqnarray*} 
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} \\
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{eqnarray*} 

\end{document}

Second question : I followed the method described in the link, and the pictures are better but in my opinion, too small. How to resize images ?

Third question : I tried to put the images in svg format, but it does not work:

   Erreur d'analyse XML : mal formé
   Emplacement : file:///home/fab/der1x.svg
   Numéro de ligne 1, Colonne 2 :
   %!PS-Adobe-3.0
   -^

Here are the contents of tex4ht.env modified and the file contents myconfig.cfg :

     <dvipng>
    G.png
    Gdvipng -T tight -x 1400 -D 72 -bg Transparent -pp %%2:%%2 %%1 -o %%3
    G.gif
    Gdvipng -T tight -x 1400 -D 72 -bg Transparent -gif -pp %%2:%%2 %%1 -o %%3
    G.
    Gdvips -Ppdf -mode ibmvga -D 110 -f %%1 -pp %%2 > zz%%4.ps
    Gconvert -crop 0x0 -density 110x110 -transparent '#FFFFFF' zz%%4.ps %%3
    Grm zz%%4.ps
    G.svg
    Gdvisvgm -n -p %%2 -c 1.2,1.2 -s %%1 > %%3
     </dvipng

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

Fourth question : use MathJax with TeX4ht gives a very good result in the test.html that the iPad opens without problems, but if you use Calibre to get an ebook, the result is very bad ! The only small problem is that with this little script accented characters are replaced by question marks :

   #!/bin/bash

    if [ $1 ]
    then
    NAME=`echo $1 | sed 's/.tex//g'`
    htlatex $1 "ht5mjlatex.cfg" "-cmozhtf"
    iceweasel $NAME.html;
    exit
    fi

It will be difficult to make an ebook using TeX4ht. I tried to install TeX4ebook, but there is an installation problem :

  fab@debian:~$ texlua /home/fab/texmf/tex/latex/tex4ebook-master /tex4ebook.lua
  /home/fab/texmf/tex/latex/tex4ebook-master/tex4ebook.lua:113: invalid  escape sequence near '\$'

Answer 1

As per the comment, some equations appear correctly after converting. This means that, these equations are converted as image by tex4ht's post process. One way to make other equation to appear correctly is to make them image as well. A sample TeX file with possible type of equations and some text added:

\documentclass[a4paper,11pt]{article} 

\usepackage[utf8]{inputenc} 
\usepackage{amsmath,amsfonts} 

\begin{document} 
\Configure{$}{\PicMath}{\EndPicMath}{}%$
\def\,{\ }

\section*{Sample French Text}

Lucie, étudiante des États-Unis, vient d'arriver à Charles de
Gaulle, l'aéroport qui accueille chaque jour à Paris, 1 million de
visiteurs. Paris. Enfin. Ça a toujours été le rêve de Lucie : vivre
dans la Ville lumière, la ville des beaux arts, du quartier latin, du
vin, et qui sait, peut-être la ville d'une petite histoire d'amour.

\section*{Math Part}
Numbered equation:
\begin{equation} 
P_{r-j}= 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{equation} 
Un-numbered equation:
\begin{equation*} 
P_{r-j}= 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{equation*} 
Inline equation: 
\( x ^ 2 - 6x +6 = 0\) and $B (x) =-x ^ 2 + 60x-500, \quad
\textrm{where $ x $ belongs to the interval $ [0 \, 60 ] $.}$ 

Un-numbered displayed equation: 
\[
B (x) =-x ^ 2 + 60x-500, \quad \textrm{where $ x $ belongs to the interval $ \left [0 \, 60 \right] $.} 
\]
and
$$
B (x) =-x ^ 2 + 60x-500, \quad \textrm{where $ x $ belongs to the interval $ \left [0 \, 60 \right] $.} 
$$
Eqnarray
\begin{eqnarray} 
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} \\
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{eqnarray} 
Starred eqnarray
\begin{eqnarray*} 
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} \\
P_{r-j}&=& 
\begin{cases} 
0 & \text{si $r-j$ est impair,} \\ 
r! \, (-1)^{(r-j)/2} & \text{si $r-j$ est pair.} 
\end{cases} 
\end{eqnarray*} 

\end{document}

After \begin{document} I have added \Configure{$}{\PicMath}{\EndPicMath}{}%$ which will convert all the inline equations to image.

You need to give the following command line to generate html:

htlatex <filename> "xhtml" "-cmozhtf"

Note: I have removed \usepackage[frenchb]{babel} and added some French text in the sample TeX.

Disclaimer: I have not tested the conversion using Calibre. Hope this will work.