sharpen image

最新推荐文章于 2023-03-10 15:00:45 发布

cv_yuippe

最新推荐文章于 2023-03-10 15:00:45 发布

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分类专栏： opencv

本文链接：https://blog.youkuaiyun.com/cv_yuippe/article/details/10363173

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本文介绍了一种使用OpenCV库实现图像锐化的技术。通过定义特定的卷积核并应用filter2D函数，实现了对输入图像的锐化处理。此外，还展示了如何创建卷积核，并详细说明了锐化过程中的关键步骤。

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内核及其自定义进行邻域操作：
代码如下：
// b2.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <OpenCV245.h>

using namespace std;
using namespace cv;


void addValue(Mat &image, int &value)
{
	/*int nl = image.rows;
	int nc = image.cols * image.channels();

	if (image.isContinuous())
	{
		nc *= nl;
		nl = 1;
	}

	for (int j = 0; j < nl; j++)
	{
		uchar* data = image.ptr<uchar>(j);
		for (int i = 0; i < nc; i++)
		{
			
			if (data[i] > 133 )
			{
				data[i] = 255;
			}
		}
	}
*/
	Mat_<Vec3b>::iterator it = image.begin<Vec3b>();
	Mat_<Vec3b>::iterator itend = image.end<Vec3b>();
	for (; it != itend ; ++it)
	{
		(*it)[0] =(*it)[0] + value;
	}
}

void sharpen(const Mat &image, Mat &result)
{
	result.create(image.size(), image.type());
	for (int j = 1; j < image.rows - 1; j++)
	{
		const uchar* previous = image.ptr<const uchar>(j - 1);
		const uchar* current = image.ptr<const uchar>(j);
		const uchar* next = image.ptr<const uchar>(j + 1);

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

		for (int i = 1; i < image.cols - 1; i++)
		{
			*output++ = saturate_cast<uchar>(5*current[i] - current[i - 1] - current[i+1] - previous[i] - next[i]);
			//saturate_cast是保证将算后的值在灰度的范围内。uchar为8位，则使其范围在0到255之间
		}

	}
	//set the unprocess pixels to 0
	result.row(0).setTo(Scalar(0));
	result.row(result.rows - 1).setTo(Scalar(0));
	result.col(0).setTo(Scalar(0));
	result.col(result.cols - 1).setTo(Scalar(0));
}


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

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

	filter2D(image, result, image.depth(), kernel);

}

int _tmain(int argc, _TCHAR* argv[])
{
	char src_window[] = "src";
	char dst_window[] = "dst";
	

	Mat src = imread("C:\\Users\\sony\\Desktop\\pic\\Lena.jpg", 0);
	Mat dst;
	int value = 50;
	double t;

	t = static_cast<double>(getTickCount());
	/*addValue(src, value);*/
	/*sharpen(src, dst);*/
	sharpen2D(src, dst);
    t = static_cast<double>(getTickCount()) - t;
	cout<<"time : "<< t*0.45<<endl;
	resize(dst,dst,Size(600, 600));
	resize(src,src,Size(600,600));
	imshow("src",src);
	imshow("dst",dst);
	waitKey(0);
	return 0;
}