pamdepth: 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/pamdepth - from package: netpbm-progs

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

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