pnmremap: 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/pnmremap - from package: netpbm-progs

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

On Debian possible default full paths are:

/usr/bin/pnmremap - from package: netpbm

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

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