实例face_eye_detection中face_cascade = image.HaarCascade("/rom/haarcascade_frontalface.cascade", stages=25)报错OSError: [Errno 19] ENODEV
代码如下

import sensor
import time
import image

sensor.set_contrast(1)
sensor.set_gainceiling(16)
sensor.set_framesize(sensor.HQVGA)
sensor.set_pixformat(sensor.GRAYSCALE)

face_cascade = image.HaarCascade("/rom/haarcascade_frontalface.cascade", stages=25)
eyes_cascade = image.HaarCascade("/rom/haarcascade_eye.cascade", stages=24)
print(face_cascade, eyes_cascade)

clock = time.clock()

while True:
clock.tick()

img = sensor.snapshot()


objects = img.find_features(face_cascade, threshold=0.5, scale_factor=1.5)


for face in objects:
    img.draw_rectangle(face)
   
    eyes = img.find_features(
        eyes_cascade, threshold=0.5, scale_factor=1.2, roi=face
    )
    for e in eyes:
        img.draw_rectangle(e)


print(clock.fps())

是实例的源代码但是报错了