jpegdump: 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/jpegdump - from package: dicom3tools

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

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