mdatopbm: 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/mdatopbm - from package: netpbm-progs

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

On Debian possible default full paths are:

/usr/bin/mdatopbm - from package: netpbm

You may install the required package with command apt-get install {package}

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