解决plt.savefig()保存到本地的图片上下左右会有白边

plt.imshow(datalistall[i])
plt.axis('off')
# plt.gca().xaxis.set_major_locator(plt.NullLocator())
# plt.gca().yaxis.set_major_locator(plt.NullLocator())
plt.margins(0, 0)
plt.savefig('自己改一下要保存的地址', bbox_inches='tight', dpi=300, pad_inches=0.0)
plt.show()

plt.axis('off')

plt.axis('off')
fig = plt.gcf()
fig.set_size_inches(7.0/3,7.0/3) #dpi = 300, output = 700*700 pixels
plt.gca().xaxis.set_major_locator(plt.NullLocator())
plt.gca().yaxis.set_major_locator(plt.NullLocator())
plt.subplots_adjust(top = 1, bottom = 0, right = 1, left = 0, hspace = 0, wspace = 0)
plt.margins(0,0)
fig.savefig(out_png_path, format='png', transparent=True, dpi=300, pad_inches = 0)

import h5py
import matplotlib.pyplot as plt
import numpy as np
import cv2
#
train_imgs = h5py.File("./datafuse/test_images.hdf5", 'r')
img = train_imgs['input_DEM'][0][...]
plt.axis('off')
fig = plt.gcf()
fig.set_size_inches(7.0/3,7.0/3)
plt.gca().xaxis.set_major_locator(plt.NullLocator())
plt.gca().yaxis.set_major_locator(plt.NullLocator())
plt.subplots_adjust(top = 1, bottom = 0, right = 1, left = 0, hspace = 0, wspace = 0)
plt.margins(0,0)
plt.imshow(img, cmap='gray')
plt.savefig('DEM.png', pad_inches = 0)
plt.show()
img = cv2.imread('DEM.png', 0)  # 原图为彩色图，可将第二个参数变为0，为灰度图
# # plt.imshow(img, cmap='gray')
# plt.show()
edges = cv2.Canny(img, 100, 200)
plt.subplot(121), plt.imshow(img, cmap='gray')
plt.title('raw'), plt.xticks([]), plt.yticks([])
plt.subplot(122), plt.imshow(edges, cmap='gray')
plt.title('Canny detecetion'), plt.xticks([]), plt.yticks([])
plt.show()