一、计算laplacian绝对值的方差

1、参考代码1

# import the necessary packages
from imutils import paths
import argparse
import cv2

def variance_of_laplacian(image):
	# compute the Laplacian of the image and then return the focus
	# measure, which is simply the variance of the Laplacian
	return cv2.Laplacian(image, cv2.CV_64F).var()


# load the image, convert it to grayscale, and compute the
# focus measure of the image using the Variance of Laplacian
# method
image = cv2.imread("C:/Users/mike/Desktop/111.png")
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
fm = variance_of_laplacian(gray)
text = "Not Blurry"
# if the focus measure is less than the supplied threshold,
# then the image should be considered "blurry"
if fm < 100:
    text = "Blurry"
# show the image
cv2.putText(image, "{}: {:.2f}".format(text, fm), (10, 30),
    cv2.FONT_HERSHEY_SIMPLEX, 0.8, (0, 0, 255), 3)
cv2.