ppmglobe: 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/ppmglobe - from package: netpbm-progs

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

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