以下是我对单个图片转化为二值灰度图的程序，没有问题;
import cv2
img = cv2.imread("/home/zhoudeliang/hed-master/image/train/75-1.jpg")
Grayimg = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
ret, thresh = cv2.threshold(Grayimg, 1, 255,cv2.THRESH_BINARY)
cv2.imwrite('/home/zhoudeliang/hed-master/image/train-1/75-1.png', thresh)
以下是我对多个图片转化为二值灰度图的程序，存在问题，但我认为逻辑上说得过去呀，请指教！！
import cv2
while 1：
  img = cv2.imread("/home/zhoudeliang/hed-master/image/train/×.jpg")
  Grayimg = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
  ret, thresh = cv2.threshold(Grayimg, 1, 255,cv2.THRESH_BINARY)
  cv2.imwrite('/home/zhoudeliang/hed-master/image/train-1/×.png', thresh)
谢谢各位！！
谢谢