import cv2
import numpy as np

img = cv2.imread('bookpage.jpg')
retval, threshold = cv2.threshold(img, 12,255,cv2.THRESH_BINARY)
grayscale = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
retval2, threshold2 = cv2.threshold(grayscale,12,255,cv2.THRESH_BINARY)
gaus = cv2.adaptiveThreshold(grayscale, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 115, 1)

cv2.imshow('original', img)
cv2.imshow('threshold', threshold)
cv2.imshow('threshold2', threshold2)
cv2.imshow('gaus', gaus) 


cv2.waitKey(0)
cv2.destroyAllWindows()