膨胀

• 此操作将图像  与任意形状的内核 ()，通常为正方形或圆形,进行卷积。

• 内核  有一个可定义的 锚点, 通常定义为内核中心点。

• 进行膨胀操作时，将内核  划过图像,将内核  覆盖区域的最大相素值提取，并代替锚点位置的相素。显然，这一最大化操作将会导致图像中的亮区开始”扩展” (因此有了术语膨胀 dilation )。对上图采用膨胀操作我们得到:

  

背景(白色)膨胀，而黑色字母缩小了。

腐蚀

• 腐蚀在形态学操作家族里是膨胀操作的孪生姐妹。它提取的是内核覆盖下的相素最小值。

• 进行腐蚀操作时，将内核  划过图像,将内核  覆盖区域的最小相素值提取，并代替锚点位置的相素。

• 以与膨胀相同的图像作为样本,我们使用腐蚀操作。从下面的结果图我们看到亮区(背景)变细，而黑色区域(字母)则变大了。

  

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "highgui.h"
#include <stdlib.h>
#include <stdio.h>using namespace cv;/// 全局变量
Mat src, erosion_dst, dilation_dst;int erosion_elem = 0;
int erosion_size = 0;
int dilation_elem = 0;
int dilation_size = 0;
int const max_elem = 2;
int const max_kernel_size = 21;/** Function Headers */
void Erosion( int, void* );
void Dilation( int, void* );/** @function main */
int main( int argc, char** argv )
{/// Load 图像src = imread( argv[1] );if( !src.data ){ return -1; }/// 创建显示窗口namedWindow( "Erosion Demo", CV_WINDOW_AUTOSIZE );namedWindow( "Dilation Demo", CV_WINDOW_AUTOSIZE );cvMoveWindow( "Dilation Demo", src.cols, 0 );/// 创建腐蚀 TrackbarcreateTrackbar( "Element:\n 0: Rect \n 1: Cross \n 2: Ellipse", "Erosion Demo",&erosion_elem, max_elem,Erosion );createTrackbar( "Kernel size:\n 2n +1", "Erosion Demo",&erosion_size, max_kernel_size,Erosion );/// 创建膨胀 TrackbarcreateTrackbar( "Element:\n 0: Rect \n 1: Cross \n 2: Ellipse", "Dilation Demo",&dilation_elem, max_elem,Dilation );createTrackbar( "Kernel size:\n 2n +1", "Dilation Demo",&dilation_size, max_kernel_size,Dilation );/// Default startErosion( 0, 0 );Dilation( 0, 0 );waitKey(0);return 0;
}/**  @function Erosion  */
void Erosion( int, void* )
{int erosion_type;if( erosion_elem == 0 ){ erosion_type = MORPH_RECT; }else if( erosion_elem == 1 ){ erosion_type = MORPH_CROSS; }else if( erosion_elem == 2) { erosion_type = MORPH_ELLIPSE; }Mat element = getStructuringElement( erosion_type,Size( 2*erosion_size + 1, 2*erosion_size+1 ),Point( erosion_size, erosion_size ) );/// 腐蚀操作erode( src, erosion_dst, element );imshow( "Erosion Demo", erosion_dst );
}/** @function Dilation */
void Dilation( int, void* )
{int dilation_type;if( dilation_elem == 0 ){ dilation_type = MORPH_RECT; }else if( dilation_elem == 1 ){ dilation_type = MORPH_CROSS; }else if( dilation_elem == 2) { dilation_type = MORPH_ELLIPSE; }Mat element = getStructuringElement( dilation_type,Size( 2*dilation_size + 1, 2*dilation_size+1 ),Point( dilation_size, dilation_size ) );///膨胀操作dilate( src, dilation_dst, element );imshow( "Dilation Demo", dilation_dst );
}

/** @function Dilation */
void Dilation( int, void* )
{int dilation_type;if( dilation_elem == 0 ){ dilation_type = MORPH_RECT; }else if( dilation_elem == 1 ){ dilation_type = MORPH_CROSS; }else if( dilation_elem == 2) { dilation_type = MORPH_ELLIPSE; }Mat element = getStructuringElement( dilation_type,Size( 2*dilation_size + 1, 2*dilation_size+1 ),Point( dilation_size, dilation_size ) );/// 膨胀操作dilate( src, dilation_dst, element );imshow( "Dilation Demo", dilation_dst );
}