numpy数组重塑astype太慢

Question

对于从摄像头读取的640x480x3图像，为TensorFlow准备图像的瓶颈是以下重塑命令：

def load_image_into_numpy_array(image):

    (im_width, im_height) = image.size
    return np.array(image.getdata()).reshape((im_height, im_width, 3)).astype(np.uint8)

为什么要花这么长时间，有什么方法可以加快速度？

Answer 1

我能够通过削减操作

import time
import picamera
import numpy as np

with picamera.PiCamera() as camera:
    camera.resolution = (320, 240)
    camera.framerate = 24
    time.sleep(2)
    output = np.empty((240, 320, 3), dtype=np.uint8)
    camera.capture(output, 'rgb')