opj2_decompress: 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_decompress - from package: openjpeg2-tools

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

Error in other languages:
opj2_decompress: bevel nie gevind nie
opj2_decompress: comandă negăsită
opj2_decompress: comando não encontrado
opj2_decompress: commande introuvable
opj2_decompress: command not found
opj2_decompress: käsku ei ole
opj2_decompress: không tìm thấy lệnh
opj2_decompress: komanda nerasta
opj2_decompress: Kommando nicht gefunden.
opj2_decompress: kommandot finns inte
opj2_decompress: komut yok
opj2_decompress: nie znaleziono polecenia
opj2_decompress: níor aimsíodh an t-ordú
opj2_decompress: no se encontró la orden
opj2_decompress: no s'ha trobat l'ordre
opj2_decompress: opdracht niet gevonden
opj2_decompress: parancs nem található
opj2_decompress: perintah tidak ditemukan
opj2_decompress: príkaz nenájdený
opj2_decompress: příkaz nenalezen
opj2_decompress: команда не найдена
opj2_decompress: командата не е открита
opj2_decompress: 命令找不到
opj2_decompress: コマンドが見つかりません