matplotlib读取ndarry格式图片并进行不失真的resize

1.

import cv2
import numpy as np
import matplotlib.pyplot as plt
from PIL import Image
from matplotlib.image import imread
def letterbox_image(image, size):
    ih, iw, _   = np.shape(image)
    w, h        = size
    scale       = min(w/iw, h/ih)
    nw          = int(iw*scale)
    nh          = int(ih*scale)

    image       = cv2.resize(image, (nw, nh))
    new_image   = np.ones([size[1], size[0], 3]) * 128
    new_image[(h-nh)//2:nh+(h-nh)//2, (w-nw)//2:nw+(w-nw)//2] = image
    return new_image

2 

if __name__=="__main__":
    img = imread('img/timg.jpg') 
    plt.subplot(1, 2, 1)
    plt.imshow(img)
    img1 = letterbox_image(img,(512,512))  
    im  = Image.fromarray(img1.astype('uint8'))
    plt.subplot(1, 2, 2)
    plt.imshow(im)
    plt.show() #显示图片