environment.py 文件源码

def preprocess(self, screen, new_game=False):
        luminance = screen.astype('float32').mean(2)  # no need in true grayscale, just take mean
        # crop top/bottom Atari specific borders
        if self.env.spec.id == 'SpaceInvaders-v0':
            # crop only bottom in SpaceInvaders, due to flying object at the top of the screen
            luminance = luminance[:-15, :]
        else:
            luminance = luminance[36:-15, :]
        # convert into [0.0; 1.0]
        s = imresize(luminance, (self.W, self.H)).astype('float32') * (1. / 255)
        s = s.reshape(1, s.shape[0], s.shape[1], 1)
        if new_game or self.stacked_s is None:
            self.stacked_s = np.repeat(s, self.memlen, axis=3)
        else:
            self.stacked_s = np.append(s, self.stacked_s[:, :, :, :self.memlen - 1], axis=3)
        return self.stacked_s