pamgauss: 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/pamgauss - from package: netpbm-progs

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

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