如何使用skimage从旋转后的图像中移除灰色边框？

from skimage import io, color, filters
import numpy as np

image = io.imread('image.jpg')
gray_image = color.rgb2gray(image)

edges = filters.sobel(gray_image)

row_sum = np.sum(edges, axis=1)
col_sum = np.sum(edges, axis=0)
row_start = np.argmax(row_sum > np.max(row_sum) * 0.1)
row_end = len(row_sum) - np.argmax(row_sum[::-1] > np.max(row_sum) * 0.1)
col_start = np.argmax(col_sum > np.max(col_sum) * 0.1)
col_end = len(col_sum) - np.argmax(col_sum[::-1] > np.max(col_sum) * 0.1)

cropped_image = image[row_start:row_end, col_start:col_end]

io.imshow(cropped_image)
io.show()