escala.py

def escala_grises(self):
        image = Image.open(self.o_imagen) 
        pixels = image.load()
        ancho,alto = image.size
        self.matriz = numpy.empty((ancho, alto))
        for i in range(ancho):
            for j in range(alto):
                (r,g,b) = image.getpixel((i,j))
                escala = (r+g+b)/3
                pixels[i,j] = (escala,escala,escala)
                self.matriz[i,j] = int(escala)
        return image