jpstoimg: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/jpstoimg - from package: latex2html

You may install the required package with command yum install {package}

Error in other languages:
jpstoimg: bevel nie gevind nie
jpstoimg: comandă negăsită
jpstoimg: comando não encontrado
jpstoimg: commande introuvable
jpstoimg: command not found
jpstoimg: käsku ei ole
jpstoimg: không tìm thấy lệnh
jpstoimg: komanda nerasta
jpstoimg: Kommando nicht gefunden.
jpstoimg: kommandot finns inte
jpstoimg: komut yok
jpstoimg: nie znaleziono polecenia
jpstoimg: níor aimsíodh an t-ordú
jpstoimg: no se encontró la orden
jpstoimg: no s'ha trobat l'ordre
jpstoimg: opdracht niet gevonden
jpstoimg: parancs nem található
jpstoimg: perintah tidak ditemukan
jpstoimg: príkaz nenájdený
jpstoimg: příkaz nenalezen
jpstoimg: команда не найдена
jpstoimg: командата не е открита
jpstoimg: 命令找不到
jpstoimg: コマンドが見つかりません