Python OpenCV：将背景颜色更改为白色

Question

任何人都可以共享用于将附加图像的背景颜色更改为白色的代码，以便我可以使用OCR软件识别数字的前景吗？

Answer 1

您需要转换为灰色，应用对比度并使用阈值来获得以下结果：

import cv2
import numpy as np

img = cv2.imread("digits.jpg", cv2.IMREAD_COLOR)
gray = cv2.cvtColor(img, cv2.COLOR_BGR2LAB)[...,0]
# edges = cv2.Canny(gray, 10,30)    
blurred = cv2.GaussianBlur(gray, (7, 7), 0)
clahe = cv2.createCLAHE(clipLimit=5.0, tileGridSize=(32,32))
contrast = clahe.apply(blurred)
ret, thresh = cv2.threshold(contrast, 20, 255, cv2.THRESH_BINARY|cv2.THRESH_OTSU)


while True:
  cv2.imshow("result", thresh)
  k = cv2.waitKey(30) & 0xff
  if k == 27:
      break