import cv2.cv2 as cv2

img = cv2.imread("E:\Photos_for_TZ\gordon.jpg")
img1 = cv2.imread("E:\Photos_for_TZ\gordon.jpg", 0)

ret, thresh = cv2.threshold(img1, 170, 255, cv2.THRESH_BINARY)
contours, hierarchy = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
print('Число контуров функции threshold:' + str(len(contours)))

blur = cv2.GaussianBlur(img1,(1,1), cv2.BORDER_DEFAULT)
canny = cv2.Canny(image = blur, threshold1 = 170, threshold2 = 230, apertureSize = 3, L2gradient = True)
contours1, hierarchy = cv2.findContours(canny, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
print('Число контуров функции Canny:'+ str(len(contours1)) +'\n')

cv2.drawContours(img, contours1, -1, (30, 170, 230), 2)

cv2.imshow('Original', img)
cv2.imshow('Grayscale', img1)
cv2.imshow('Threshold', thresh)
cv2.imshow('Canny', canny)

cv2.waitKey(0)
cv2.destroyAllWindows()