pixelize: 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 Debian possible default full paths are:

/usr/bin/pixelize - from package: pixelize

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

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