tifffile: 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/tifffile - from package: python-tifffile

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

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