dcml2pnm: 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/dcml2pnm - from package: dcmtk

You may install the required package with command apt-get install {package}
Error in other languages:
dcml2pnm: bevel nie gevind nie
dcml2pnm: comandă negăsită
dcml2pnm: comando não encontrado
dcml2pnm: commande introuvable
dcml2pnm: command not found
dcml2pnm: käsku ei ole
dcml2pnm: không tìm thấy lệnh
dcml2pnm: komanda nerasta
dcml2pnm: Kommando nicht gefunden.
dcml2pnm: kommandot finns inte
dcml2pnm: komut yok
dcml2pnm: nie znaleziono polecenia
dcml2pnm: níor aimsíodh an t-ordú
dcml2pnm: no se encontró la orden
dcml2pnm: no s'ha trobat l'ordre
dcml2pnm: opdracht niet gevonden
dcml2pnm: parancs nem található
dcml2pnm: perintah tidak ditemukan
dcml2pnm: príkaz nenájdený
dcml2pnm: příkaz nenalezen
dcml2pnm: команда не найдена
dcml2pnm: командата не е открита
dcml2pnm: 命令找不到
dcml2pnm: コマンドが見つかりません