pbmpage: 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/pbmpage - from package: netpbm-progs

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

On Debian possible default full paths are:

/usr/bin/pbmpage - from package: netpbm

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

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