How to get pixel locations of 4 corner white pixels in a binary image

Question

I have a binary raster image as shown below:

import rasterio
import numpy as np

path = r'D:\LE07_L1TP_147048_20070221_20170105_01_T1\LE07_L1TP_147048_20070221_20170105_01_T1_B1.tif'

with rasterio.open(path) as dataset:
    image = dataset.read(1)
    mask = np.where(image > 1, 255, 0)

white_pixels = np.array(np.where(mask == 255))
pixel_1 = white_pixels[:,0]
pixel_4 = white_pixels[:,-1]

By running the above code I am able to get locations of "pixel_1" & "pixel_4". Can someone help me out in getting pixel locations of "pixel_2" & "pixel_3".

Answer 1

Find x and then y.

white_pixels_x = np.nonzero(np.sum(mask, axis=0))

p3x = white_pixel_x[0][0]
p2x = white_pixel_x[0][-1]

p3y = np.nonzero(mask[:, p3x])[0][0]
p2y = np.nonzero(mask[:, p2x])[0][0]