Python中读取和保存图像的各种方法

以你之姓@ 2022-03-09 00:54 354阅读 0赞

python中图像处理相关库有很多，这里简单介绍PIL、cv2、scipy.imageio 、matplotlib.image、skimage等常用库，其中PIL库使用最方便，cv2库功能最强大。

### PIL：Python Imaging Library ###

python安装：pip install Pillow  
这里只给出读取、形状变化、图像转array、array转图像，以及保存图像的方法。

import numpy as np
    from PIL import Image
    import matplotlib.pyplot as plt
    %matplotlib inline
    
    # read image
    raw_image = Image.open("panda.jpg")
    # image resize
    image_resize = raw_image.resize((128, 128))
    # image to array
    image_array = np.array(image_resize)
    # array to image
    image_output = Image.fromarray(image_array)
    # save image
    image_output.save("new_panda.jpg")
    
    plt.imshow(raw_image)
    plt.axis("off")
    plt.show()

![在这里插入图片描述][20190311220243562.png]

### cv2: opencv-python ###

python下安装：pip install opencv-python  
python中的openCV库，非常强大，可以对图像做各种处理，这里暂时只给出读取和保存的方法。

import cv2
    
    # read image, return np.array with BGR
    raw_image = cv2.imread("panda.jpg")
    # BGR to RGB
    image_rgb = cv2.cvtColor(raw_image,cv2.COLOR_BGR2RGB)
    # image resize
    image_resize = cv2.resize(raw_image, (128, 128))
    # save image
    cv2.imwrite("new_panda.jpg", image_resize)

### keras.preprocessing ###

keras中处理图像的工具，其实底层处理用的PIL，不过多讲解。

from keras.preprocessing import image
    
    # read image
    raw_image = image.load_img("panda.jpg", target_size=(128, 128))
    # image to array
    image_array = image.img_to_array(raw_image)
    # array to image
    image_output = image.array_to_img(image_array)
    # save image
    image_output.save("new_panda.jpg")

### scipy.imageio ###

安装：pip install imageio  
科学计算库scipy中的方法，之前是scipy.misc，新版用imageio，misc弃用。

from imageio import imread, imsave
    
    # read image
    raw_image = imread("panda.jpg")
    # save image
    imsave("new_panda.jpg", image_resize)
    # show image
    plt.imshow(image_resize)
    plt.axis("off")
    plt.show()

### matplotlib.image ###

绘图工具库matplotlib中的方法

import matplotlib.image as mpimg
    
    # read image , return np.array
    raw_image = mpimg.imread("panda.jpg")
    # save image
    mpimg.imsave("new_panda.jpg", raw_image)
    # show image
    plt.imshow(raw_image)
    plt.axis("off")
    plt.show()

### skimage: Scikit-Image ###

安装：pip install -U scikit-image  
Scikit-Image图像处理是在scipy基础上扩展的，有兴趣可以了解。

from skimage import io
    
    # read image
    raw_image = io.imread("panda.jpg")
    # save image
    io.imsave("new_panda.jpg", raw_image)
    # show image
    io.imshow(raw_image)

[20190311220243562.png]: /images/20220309/ad61c56252e547dc869568482195c7a3.png