Resize an image without distortion OpenCV
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.
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.
If you need to modify the image resolution and keep your aspect ratio use the function imutils (check documentation). something like this:
img = cv2.imread(file , 0)
img = imutils.resize(img, width=1280)
cv2.imshow('image' , img)
hope that helps, good luck !