image_buffer.py 文件源码

def callback(data):
        """Callback function for subscribing to an Image topic and creating a buffer
        """
        global dtype
        global images_so_far

        # Get cv image (which is a numpy array) from data
        cv_image = bridge.imgmsg_to_cv2(data)
        # Save dtype before we float32-ify it
        dtype = str(cv_image.dtype)
        # Insert and roll buffer
        buffer.insert(0, (np.asarray(cv_image, dtype='float32'), rospy.get_time()))
        if(len(buffer) > bufsize):
            buffer.pop()

        # for showing framerate
        images_so_far += 1

    # Initialize subscriber with our callback