opj2_dump: 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/opj2_dump - from package: openjpeg2-tools

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

Error in other languages:
opj2_dump: bevel nie gevind nie
opj2_dump: comandă negăsită
opj2_dump: comando não encontrado
opj2_dump: commande introuvable
opj2_dump: command not found
opj2_dump: käsku ei ole
opj2_dump: không tìm thấy lệnh
opj2_dump: komanda nerasta
opj2_dump: Kommando nicht gefunden.
opj2_dump: kommandot finns inte
opj2_dump: komut yok
opj2_dump: nie znaleziono polecenia
opj2_dump: níor aimsíodh an t-ordú
opj2_dump: no se encontró la orden
opj2_dump: no s'ha trobat l'ordre
opj2_dump: opdracht niet gevonden
opj2_dump: parancs nem található
opj2_dump: perintah tidak ditemukan
opj2_dump: príkaz nenájdený
opj2_dump: příkaz nenalezen
opj2_dump: команда не найдена
opj2_dump: командата не е открита
opj2_dump: 命令找不到
opj2_dump: コマンドが見つかりません