vipsheader: 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/vipsheader - from package: libvips-tools

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

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