image_to_j2k: 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/image_to_j2k - from package: openjpeg

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

On Debian possible default full paths are:

/usr/bin/image_to_j2k - from package: openjpeg-tools

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

Error in other languages:
image_to_j2k: bevel nie gevind nie
image_to_j2k: comandă negăsită
image_to_j2k: comando não encontrado
image_to_j2k: commande introuvable
image_to_j2k: command not found
image_to_j2k: käsku ei ole
image_to_j2k: không tìm thấy lệnh
image_to_j2k: komanda nerasta
image_to_j2k: Kommando nicht gefunden.
image_to_j2k: kommandot finns inte
image_to_j2k: komut yok
image_to_j2k: nie znaleziono polecenia
image_to_j2k: níor aimsíodh an t-ordú
image_to_j2k: no se encontró la orden
image_to_j2k: no s'ha trobat l'ordre
image_to_j2k: opdracht niet gevonden
image_to_j2k: parancs nem található
image_to_j2k: perintah tidak ditemukan
image_to_j2k: príkaz nenájdený
image_to_j2k: příkaz nenalezen
image_to_j2k: команда не найдена
image_to_j2k: командата не е открита
image_to_j2k: 命令找不到
image_to_j2k: コマンドが見つかりません