CODEWITHSUNDEEP
opencvtesseract
Benjamin Ing
Benjamin Ing

Reputation: 33

Processing an image with block letters for OCR

I would like to OCR this battle log from a game:

battle log image

The original image had block text font, so after thresholding I inverted the colors. Now I want to remove the "black" background (but not the black text), but I'm not sure how to achieve that in OpenCV. Afterwards I imagine I would like to sharpen the text to be thicker for better OCR.

May I ask how I can go about this?

Upvotes: 1

Views: 436

Answers (1)

Ha Bom
Ha Bom

Reputation: 2927

Try this out. 

import cv2
import numpy as np

img = cv2.imread("1.png")

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

invert0 = cv2.bitwise_not(gray)

_,thresh = cv2.threshold(invert0,128,255,cv2.THRESH_BINARY)

invert1 = cv2.bitwise_not(thresh)

im2, contours, hierarchy = cv2.findContours(invert1,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)

mask = np.zeros(gray.shape, dtype="uint8")
for i in range(len(contours)):
    if(hierarchy[0][i][3]==-1): #contour has no parent (most outer contour)
        cv2.fillPoly(mask, pts =[contours[i]], color=255)

invert2 = cv2.bitwise_not(mask)
res = invert2 + invert1

cv2.imshow("img", img)    
cv2.imshow("gray", gray)   
cv2.imshow("invert0", invert0) 
cv2.imshow("thresh", thresh) 
cv2.imshow("invert1", invert1) 
cv2.imshow("invert2", invert2)
cv2.imshow("mask", mask)
cv2.imshow("res", res)

cv2.waitKey()
cv2.destroyAllWindows()

enter image description here

Upvotes: 3

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