图像锐化

#include<opencv2\highgui.hpp>
#include<opencv2\imgproc.hpp>
#include<iostream>
using namespace std;

void sharpen(const cv::Mat image,cv::Mat &result){
	result.create(image.size(),image.type());
	int nchannels=image.channels();

	for(int i=1;i<image.rows-1;i++){
		const uchar* previous=image.ptr<uchar>(i-1);
		const uchar* current=image.ptr<uchar>(i);
		const uchar* next=image.ptr<uchar>(i+1);

		uchar* output=result.ptr<uchar>(i);

		for(int j=nchannels;j<(image.cols-1)*nchannels;j++){
			*output++ =cv::saturate_cast<uchar>(5*current[j]-current[j-nchannels]-current[j+nchannels]-previous[j]-next[j]);
		}
	}
	result.row(0).setTo(cv::Scalar(0));
	result.row(result.rows-1).setTo(cv::Scalar(0));
	result.col(0).setTo(cv::Scalar(0));
	result.col(result.cols-1).setTo(cv::Scalar(0));
}

void sharpen2D(const cv::Mat image,cv::Mat &result){
	cv::Mat kernel(3,3,CV_32F,cv::Scalar(0));

	kernel.at<float>(1,1)=5.0;
	kernel.at<float>(1,0)=-1.0;
	kernel.at<float>(1,2)=-1.0;
	kernel.at<float>(0,1)=-1.0;
	kernel.at<float>(2,1)=-1.0;

	cv::filter2D(image,result,image.depth(),kernel);
}

void main(){
	cv::Mat image=cv::imread("tower.jpg");
	cv::imshow("原图",image);

	cv::Mat result;
	const int64 start=cv::getTickCount();
	sharpen(image,result);
	double duration=(cv::getTickCount()-start)/cv::getTickFrequency();
	cv::imshow("sharpen",result);
	cout<<"图像锐化的第一种方法：自己遍历并处理每个像素    耗时："<<duration<<"秒\n";

	cv::Mat result2;
	const int64 start2=cv::getTickCount();
	sharpen2D(image,result2);
	double duration2=(cv::getTickCount()-start2)/cv::getTickFrequency();
	cv::imshow("filter2D",result2);
	cout<<"图像锐化的第二种方法：filter2D    耗时："<<duration2<<"秒\n";

	cv::waitKey();
}