Simplest way to convert a low-resolution black and white picture to a matrix-CodePudding

I have a set of very low-resolution pictures (in .png but I can easily convert them to something else). They all only have black or white pixels, like QR codes.

What I want is to be able to read them as binary matrix (a 1 for a black pixel and a zero for a white one).

I don't need anything more fancy than that, what should I use?

CodePudding user response：

Hi you can use PIL to read the image, and then numpy to convert it to a matrix

from PIL import Image
import numpy as np

im = Image.read("imageName.ext")
im_mat = np.asarray(im)

Alternatively you can do all in one step with opencv

import cv2

img = cv2.imread("imageName.ext")

in both cases you will have a matrix with size WxHxC with H the height in pixels, W the widht and c the number of channels (3 or 4 depending if there's an alpha for transparency).

If your image is black and white and you only want a matrix with size WxH take one channel with

img = img_mat[:,:,0] #8-bit matrix

and last you can binarize that givving an umbral or just by comparing

bin = img> 128

bin = img == 255

I corrected this last line I had a typo in it