batch_crop: 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 Debian possible default full paths are:

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

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

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