Resize an image without distortion OpenCV

Question

I am using python 3 and latest version of openCV. I am trying to resize an image using the resize function provided but after resizing the image is very distorted. Code :

import cv2 file = "/home/tanmay/Desktop/test_image.png" img = cv2.imread(file , 0) print(img.shape) cv2.imshow('img' , img) k = cv2.waitKey(0) if k == 27:     cv2.destroyWindow('img') resize_img = cv2.resize(img  , (28 , 28)) cv2.imshow('img' , resize_img) x = cv2.waitKey(0) if x == 27:     cv2.destroyWindow('img') 

The original image is 480 x 640 (RGB therefore i passed the 0 to get it to grayscale)

Is there any way i could resize it and avoid the distortion using OpenCV or any other library perhaps? I intend to make a handwritten digit recogniser and i have trained my neural network using the MNIST data therefore i need the image to be 28x28.

Answer 1

You may try below. The function will keep the aspect rate of the original image.

def image_resize(image, width = None, height = None, inter = cv2.INTER_AREA):     # initialize the dimensions of the image to be resized and     # grab the image size     dim = None     (h, w) = image.shape[:2]      # if both the width and height are None, then return the     # original image     if width is None and height is None:         return image      # check to see if the width is None     if width is None:         # calculate the ratio of the height and construct the         # dimensions         r = height / float(h)         dim = (int(w * r), height)      # otherwise, the height is None     else:         # calculate the ratio of the width and construct the         # dimensions         r = width / float(w)         dim = (width, int(h * r))      # resize the image     resized = cv2.resize(image, dim, interpolation = inter)      # return the resized image     return resized 

Here is an example usage.

image = image_resize(image, height = 800) 

Hope this helps.