dh_perl_imager: 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/dh_perl_imager - from package: libimager-perl

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

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