拉普拉斯线性滤波,.边缘检測
Laplacian
Calculates the Laplacian of an image.
- C++: void Laplacian(InputArray src, OutputArray dst, int ddepth, int ksize=1, double scale=1, double delta=0, int borderType=BORDER_DEFAULT )
- Python: cv2.Laplacian(src, ddepth[, dst[, ksize[, scale[, delta[, borderType]]]]]) → dst
-
C: void cvLaplace(const CvArr* src, CvArr* dst, int aperture_size=3 )
highlight=laplace#void cvLaplace(const CvArr* src, CvArr* dst, int aperture_size)" title="Permalink to this definition" style="color: rgb(101, 161, 54); text-decoration: none; visibility: hidden; font-size: 0.8em; padding: 0px 4px;">
- Python: cv.Laplace(src, dst, apertureSize=3) → None
-
Parameters: - src – Source image.
- dst – Destination image of the same size and the same number of channels as src .
- ddepth – Desired depth of the destination image.
- ksize – Aperture size used to compute the second-derivative filters. See getDerivKernels() for details. The size must be positive and odd.
-
scale – Optional scale factor for the computed Laplacian values. By default, no scaling is applied. See
highlight=laplace#void getDerivKernels(OutputArray kx, OutputArray ky, int dx, int dy, int ksize, bool normalize, int ktype)" title="void getDerivKernels(OutputArray kx, OutputArray ky, int dx, int dy, int ksize, bool normalize, int ktype)" style="color: rgb(0, 144, 217); text-decoration: none;">getDerivKernels()
for details. - delta – Optional delta value that is added to the results prior to storing them in dst .
-
borderType – Pixel extrapolation method. See
highlight=laplace#int borderInterpolate(int p, int len, int borderType)" title="int borderInterpolate(int p, int len, int borderType)" style="color: rgb(0, 144, 217); text-decoration: none;">borderInterpolate()
for details.
The function calculates the Laplacian of the source image by adding up the second x and y derivatives calculated using the Sobel operator:
This is done when ksize > 1 . When ksize == 1 , the Laplacian is computed by filtering the image with the following 
aperture:
Laplace
计算图像的 Laplacian 变换
void cvLaplace( const CvArr* src, CvArr* dst, int aperture_size=3 );
- src
- 输入图像.
- dst
- 输出图像.
- aperture_size
- 核大小 (与 cvSobel 中定义一样).
函数 cvLaplace 计算输入图像的 Laplacian变换，方法是先用 sobel 算子计算二阶 x- 和 y- 差分，再求和:
对 aperture_size=1 则给出最快计算结果，相当于对图像採用例如以下内核做卷积：
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# -*- coding: utf-8 -*-
#线性锐化滤波，拉普拉斯图像变换
#code:myhaspl@myhaspl.com
import cv2 fn="test6.jpg"
myimg=cv2.imread(fn)
img=cv2.cvtColor(myimg,cv2.COLOR_BGR2GRAY) jgimg=cv2.Laplacian(img,-1)
cv2.imshow('src',img)
cv2.imshow('dst',jgimg)
cv2.waitKey()
cv2.destroyAllWindows()
