unprocessed_raw: 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/unprocessed_raw - from package: LibRaw-samples

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

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