Python: Letter repair using OpenCV for text recognition

Question

I am trying to repair image contains letters each letter split into two halves from the middle.

original Image

After Applying the following code:

gray = cv2.cvtColor(cropped_bot, cv2.COLOR_BGR2GRAY)

new_img = ((gray >= 230)*255).astype('uint8')    

bottom_image =  255-new_img

I get this Image

My Problem is to fix the line that split the letters into two part.

I have tried adaptiveThreshold

cv2.adaptiveThreshold(gray, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY, 15, 2)

But it doesn't help. How I can solve this

Possible duplicate of [How to identify incomplete rectangles in openCV](https://stackoverflow.com/questions/44295099/how-to-identify-incomplete-rectangles-in-opencv) — ivan_pozdeev, Jun 15 '18 at 19:33

score 3 · Accepted Answer · edited Jun 20 '20 at 09:12

3

Here are a few steps you can follow:

Code :

ret, thresh1 = cv2.threshold(gray, 0, 255, cv2.THRESH_BINARY | cv2.THRESH_OTSU)
cv2.imshow('thresh1', thresh1)

k = np.array([[1, 1, 1], [1, 1, 1], [1, 1, 1]], np.uint8)
closing = cv2.morphologyEx(thresh1, cv2.MORPH_CLOSE, k)
cv2.imshow(closing, closing)

UPDATE:

k1 = np.ones((3, 3), np.uint8)
erosion = cv2.erode(closing, k1, iterations = 1)
cv2.imshow(erosion, erosion)

edited Jun 20 '20 at 09:12

Community

answered Jun 16 '18 at 09:45

Jeru Luke

1

**Perfect** (Y) – ahmed osama Jun 16 '18 at 11:59
I have a small problem. a big line appears when I convert black and white as here https://ibb.co/cgx7ed – ahmed osama Jun 16 '18 at 12:04
@ahmedosama How are you getting this image? – Jeru Luke Jun 16 '18 at 13:22
`closing = 255-closing` – ahmed osama Jun 16 '18 at 14:29
@ahmedosama I did `closing = 255-closing` but I got something different. Check the result I got in the answer. – Jeru Luke Jun 16 '18 at 14:58
sorry. i found the reason for this line `closing =cv2.adaptiveThreshold(closing , 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY, 15, 2)` – ahmed osama Jun 16 '18 at 15:53
@ahmedosama Hope you've got the result you expected – Jeru Luke Jun 16 '18 at 16:01
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/173270/discussion-between-ahmed-osama-and-jeru-luke). – ahmed osama Jun 16 '18 at 16:10