Matplotlib 将刻度位置与图像像素边界对齐

Question

I am generating images with numpy , using matplotlib to visualize regions I care about, and then using pillow to save them as PNGs. When I am plotting the images, the tick marks and labels are centered on the pixels instead of on pixel boundaries:

Is there a way I could left/top justify the ticks and labels? I've found info on moving the labels, but not the ticks.

I have also tried using the axis interface with ax.major_ticklabels.set_ha("left") and ax.major_ticklabels.set_va("top") as documented here but can't get it to work. I expected 0 to be right on the edge and 1 right in the middle but I can't get this behavior.

import matplotlib.pyplot as plt
from PIL import Image
import numpy as np

image_size = (2, 2)
data = np.zeros(image_size)
data[0][0] = 255
data[1][1] = 255
plt.xticks([0, 1])
plt.yticks([0, 1])
plt.imshow(Image.fromarray(data).convert("L"))
plt.show()

Answer 1

Here is the solution:

from PIL import Image
import numpy as np
import matplotlib.pyplot as plt

image_size = (2, 2)
data = np.zeros(image_size)
data[0][0] = 255
data[1][1] = 255
x= [0,.5]
y= [0,.5]
labels = (0,1)
plt.xticks(x, labels)
plt.yticks(y, labels)
plt.imshow(Image.fromarray(data).convert("L"),extent = [0, 1,0 ,1])
plt.show()