j2k_to_image: 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/j2k_to_image - from package: openjpeg

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

On Debian possible default full paths are:

/usr/bin/j2k_to_image - from package: openjpeg-tools

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

Error in other languages:
j2k_to_image: bevel nie gevind nie
j2k_to_image: comandă negăsită
j2k_to_image: comando não encontrado
j2k_to_image: commande introuvable
j2k_to_image: command not found
j2k_to_image: käsku ei ole
j2k_to_image: không tìm thấy lệnh
j2k_to_image: komanda nerasta
j2k_to_image: Kommando nicht gefunden.
j2k_to_image: kommandot finns inte
j2k_to_image: komut yok
j2k_to_image: nie znaleziono polecenia
j2k_to_image: níor aimsíodh an t-ordú
j2k_to_image: no se encontró la orden
j2k_to_image: no s'ha trobat l'ordre
j2k_to_image: opdracht niet gevonden
j2k_to_image: parancs nem található
j2k_to_image: perintah tidak ditemukan
j2k_to_image: príkaz nenájdený
j2k_to_image: příkaz nenalezen
j2k_to_image: команда не найдена
j2k_to_image: командата не е открита
j2k_to_image: 命令找不到
j2k_to_image: コマンドが見つかりません