Scharr算子与Sobel算子相比,卷积核中的权重值更大,意味着能检测到更加细微的边缘。
laplacian算子,二阶的微分离散化。
import cv2 #opencv读取的格式是BGR
import numpy as np
import matplotlib.pyplot as plt#Matplotlib是RGB
%matplotlib inline
# 读取lena
img = cv2.imread('lena.jpg',cv2.IMREAD_GRAYSCALE)
# sobel算子
sobelx = cv2.Sobel(img,cv2.CV_64F,1,0,ksize=3)
sobely = cv2.Sobel(img,cv2.CV_64F,0,1,ksize=3)
sobelx = cv2.convertScaleAbs(sobelx)
sobely = cv2.convertScaleAbs(sobely)
sobelxy = cv2.addWeighted(sobelx,0.5,sobely,0.5,0)
# scharr算子
scharrx = cv2.Scharr(img,cv2.CV_64F,1,0)
scharry = cv2.Scharr(img,cv2.CV_64F,0,1)
scharrx = cv2.convertScaleAbs(scharrx)
scharry = cv2.convertScaleAbs(scharry)
scharrxy = cv2.addWeighted(scharrx,0.5,scharry,0.5,0)
#拉普拉斯算子
laplacian = cv2.Laplacian(img,cv2.CV_64F)
laplacian = cv2.convertScaleAbs(laplacian)
#对比效果
res = np.hstack((img,sobelxy,scharrxy,laplacian))
cv_show(res,'res')
Sobel算子,Scharr算子,lapalcian算子效果比较。