How to read pictures in Python

Whether it is used for machine learning or deep learning, it requires the operation of reading images.

Method 1: Use the Image function in PIL. This function reads not in array format (recommended learning: Python video tutorial)

At this time you need to use np.asarray(im) or np.array() function

The difference is that np.array() is a deep copy, np.asarray() is a shallow copy Copy

from PIL import Image
import numpy as np
 
I = Image.open('./cc_1.png') 
I.show()    
I.save('./save.png')
I_array = np.array(I)
print I_array.shape

Method 2: Use matplotlib.pyplot as plt to display pictures

# matplotlib.image as mpimg 用于读取图片
# 并且读取出来就是array格式
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import numpy as np
I = mpimg.imread('./cc_1.png')
print I.shape
plt.imshow(I)

Method 3: Use opencv-python interface

#cv2.imread()读出来同样是array形式，但是如果是单通道的图，读出来的是三通道的
import cv2
I = cv2.imread('./cc_1.png')
print I.shape

Method 4: To access images, I generally like to use the library scipy. It reads it in matrix form and saves it in the form of (H, W, C)

import matplotlib.pyplot as plt
from scipy import misc
import scipy
I = misc.imread('./cc_1.png')
scipy.misc.imsave('./save1.png', I)
plt.imshow(I)
plt.show()

Method Five: Use the skimage library

from skimage import io,data
img=data.lena()
io.imshow(img)

For more Python related technical articles, please visit the Python Tutorial column to learn!

The above is the detailed content of How to read pictures in Python. For more information, please follow other related articles on the PHP Chinese website!