ptova grayscale

Signed-off-by: Sebastiano Mariani <seba0691@gmail.com>
compila

Signed-off-by: Sebastiano Mariani <seba0691@gmail.com>
commentato codice

Signed-off-by: Sebastiano Mariani <seba0691@gmail.com>
fatto Android.mk per far convivere piu moduli

Signed-off-by: Sebastiano Mariani <seba0691@gmail.com>
merge ndk_grayscale

Signed-off-by: Sebastiano Mariani <seba0691@gmail.com>