如何在 python 的单个列表中制作每个强度值的像素？

Question

I need to make the pixels with the same intensity value in a list so I will get a list of lists of intensity values and each list has the pixels with the same intensity value.

import nibabel as nib
import numpy as np 
from PIL import Image
import seaborn as sns
import matplotlib.pyplot as plt
from numpy import asarray
from scipy import ndimage, misc, stats
import cv2


### Load the image 

img  = nib.load('input_dir/FLAIR1.nii.gz')
img_data = img.get_fdata()
imgs = img_data[:, :, 23]

rows, col = imgs.shape
my_nlist = [[] for k in range(y.shape[0])]
print(im_arr[2,2])
for i in range(0, rows):
    for j in range(0, col): 
        pixel = imgs[i, j]
        for k in range(y.shape[0]):
            if pixel == [k]:               
                my_nlist[k].append(pixel) 

Answer 1

Don't make it harder on yourself than you have to:) this is exactly what a histogram is meant for!

import matplotlib.pyplot as plt
import cv2 as cv # You won't be needing cv2, it is just needed to create this example

img = cv.imread('dir/to/img', 0) # notice the grayscale flag
hist, bins, _ = plt.hist(img) # hist contains the list of pixels with the same intensity for each intensity in the picture
plt.show() # in case you want to visualize it

This is what it will look like: