將圖像二值化井辆，像素值大于128的變?yōu)?孕惜，否則變?yōu)?
from PIL import Image
import numpy as np
import matplotlib.pyplot as plt
img = np.array(Image.open('pokemon.jpg').convert('L')) #打開圖片
rows,cols=img.shape #獲取像素坐標(biāo)（rows,cols）
for i in range(rows):
for j in range(cols):
if (img[i,j]<=128): #判斷該點(diǎn)的值
img[i,j]=0
else:
img[i,j]=1
plt.figure("lena") #lena嘛
plt.imshow(img,cmap='gray')
plt.axis('off')
plt.show()
