detect_spheres_matched_filter: 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/lib/cmtk/bin/detect_spheres_matched_filter - from package: cmtk

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

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