opencv remove lines from image,keep numbers

1, first convert the image to grayscale image noted as A;

2, use Hough's circle to detect the largest ellipse in A, and then create a circle of the same radius in the new image to get B;

3, for the grayscale image and the image with the circle drawn, apply OpenCV's bitwise_and and operation to extract only the ellipse image region in the original grayscale image A, which is recorded as C;

4, set a suitable threshold for image C to extract text to finally get D;

5, do the bitwise_or operation on image A and D, that is, to be able to get the final image E.