yuvsplittoppm: 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 CentOS possible default full paths are:

/usr/bin/yuvsplittoppm - from package: netpbm-progs

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/yuvsplittoppm - from package: netpbm

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

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