Remove white space from an image using python

March 12, 2022

There are multiple images that have white spaces that I need to remove. Simply to crop the image so as to get rid of the white spaces
Here’s the code I found but didn’t satisfy my needs

import numpy as np
import cv2

img = cv2.imread('Sample.png')
img = img[:-5,:-5] 
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
gray = 255*(gray < 128).astype(np.uint8)
gray = cv2.morphologyEx(gray, cv2.MORPH_OPEN, np.ones((2, 2), dtype=np.uint8))
coords = cv2.findNonZero(gray)
x, y, w, h = cv2.boundingRect(coords)
rect = img[y:y+h, x:x+w] 
cv2.imshow("Cropped", rect)
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.imwrite("Output.png", rect)

Here’s the sample image

And this is the desired output

>Solution :

The code is almost perfect. It just can’t crop on the right side because of the scrollbar. And it does not consider some padding (which you liked according the comments).

The thing I removed is the topology modification.

import numpy as np
import cv2

img = cv2.imread('cropwhitefromimage.png')
scrollbarright = 20
img = img[:, :-scrollbarright]
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
gray = 255*(gray < 128).astype(np.uint8)
coords = cv2.findNonZero(gray)
x, y, w, h = cv2.boundingRect(coords)
padding = 10
rect = img[y-padding:y+h+padding, x-padding:x+w+padding]
cv2.imshow("Cropped", rect)
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.imwrite("cropwhitefromimage_result.png", rect)