subpix: command not found

Have You tried accessing the binary with the full path?

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/subpix - from package: wcstools

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