如何用 python 制作二值图像？

Question

我用 cv2.THRESH_BINARY 和函数

构建了我的图像

ret, im_thresh = cv2.threshold( gray_image, 40, 255, cv2.THRESH_BINARY )

但是怀特必须是 1 才能使用我的程序。

为了帮助我做了：

height = int(np.size(im_thresh, 0))
width = int(np.size(im_thresh, 1))

for x in range(height):
    for y in range(width):
        if im_thresh[x,y]==255:
            im_thresh[x,y] = 1

我的问题：有什么方法可以在 python 中更快地做到这一点？

Answer 1

尝试使用布尔索引来获取和设置数组的值，从而避免嵌套的 for 循环。

import numpy as np
from numpy import random

# Generating an image of values between 1 and 255. 
im_thresh = random.randint(1,256, (64,64))

# Set anything less than 255 to 0. Unnecessary if cv2 does this during threshold. 
# Must go before the operation below in order not to set all values to 0. 
im_thresh[im_thresh<255] = 0

# Set all values at indices where the array equals 255 to 1.
im_thresh[im_thresh==255] = 1

如何用 python 制作二值图像？

How to make a binary image with python?

python

binary

rgb

image