pklas2img: 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/pklas2img - from package: pktools

You may install the required package with command apt-get install {package}
Error in other languages:
pklas2img: bevel nie gevind nie
pklas2img: comandă negăsită
pklas2img: comando não encontrado
pklas2img: commande introuvable
pklas2img: command not found
pklas2img: käsku ei ole
pklas2img: không tìm thấy lệnh
pklas2img: komanda nerasta
pklas2img: Kommando nicht gefunden.
pklas2img: kommandot finns inte
pklas2img: komut yok
pklas2img: nie znaleziono polecenia
pklas2img: níor aimsíodh an t-ordú
pklas2img: no se encontró la orden
pklas2img: no s'ha trobat l'ordre
pklas2img: opdracht niet gevonden
pklas2img: parancs nem található
pklas2img: perintah tidak ditemukan
pklas2img: príkaz nenájdený
pklas2img: příkaz nenalezen
pklas2img: команда не найдена
pklas2img: командата не е открита
pklas2img: 命令找不到
pklas2img: コマンドが見つかりません