light_correct: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/bin/light_correct - from package: libvips-tools

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