Opencv + FFTW3 圖象高斯高低通濾波

1：LPF

公式：out(i,j) = exp(-((i-M/2)^2+(j-N/2)^2)/2/sigma^2);

代碼：

        

void LPF_Fliter(vector<double>&data, int cols, int rows, double gamma)
{
	float gamma22 = 2 * gamma*gamma;
	float temp = 0.0;
	int halfRows = cvRound(rows / 2);
	int halfCols = cvRound(cols / 2);
	char debug[12] = { 0 };
	for (int j = 1; j <= rows; j++)
	{
		for (int i = 1; i <= cols; i++)
		{
			temp = (pow(j - halfRows, 2) + pow(i - halfCols, 2));
			data.push_back(exp(-temp / gamma22));
		}
	}
}

2：HPF:

公式：out(i,j) = 1 - exp(-((i-M/2)^2+(j-N/2)^2)/2/sigma^2);

代碼：

 

void HPF_Fliter(vector<double>&data, int cols, int rows, double gamma)
{
#if 1
	float gamma22 = 2 * gamma*gamma;
	float temp = 0.0;
	int halfRows = cvRound(rows / 2);
	int halfCols = cvRound(cols / 2);
	char debug[12] = { 0 };
	for (int j = 1; j <= rows; j++)
	{
		for (int i = 1; i <= cols; i++)
		{
			temp = (pow(j - halfRows, 2) + pow(i - halfCols, 2));
			data.push_back(1.0 - exp(-temp / gamma22));
		}
	}
#else
	
	fstream readFile("C:\\Users\\Tony\\Desktop\\debug.txt", ios::in);
	string temp;
	int lineCount = 0;
	while (getline(readFile, temp))
	{
		vector<string>dest;
		split(temp, "\t", dest);
		lineCount++;
		if (dest.size() > 1)
		{
			for (int i = 0; i < dest.size(); i++)
			{
				//printf_s("%s\tn", dest.at(i));
				data.push_back(atof(dest.at(i).c_str()));

			}
		}

		//printf_s("\n");
	}
#endif
}

//生成頻譜圖：

                   

//生成頻譜模板
void test()
{
	int  i;
	fftw_complex*din, *out;
	fftw_plan p,backp;

	Mat image = imread("C:\\Users\\Tony\\Desktop\\Image\\lenaCopy.bmp", CV_LOAD_IMAGE_GRAYSCALE);
	din = (fftw_complex *)fftw_malloc(sizeof(fftw_complex)*image.cols*image.rows);
	out = (fftw_complex *)fftw_malloc(sizeof(fftw_complex)*image.cols*image.rows);


	Mat floatImage(image.size(), CV_32FC1);
	image.convertTo(floatImage, CV_32FC1);
	

	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			din[i + j*image.cols][0] = *floatImage.ptr<float>(j, i);
			din[i + j*image.cols][1] = 0;
		}
	}
	//forward fft
	p = fftw_plan_dft_2d(image.rows, image.cols, din, out, FFTW_FORWARD, FFTW_ESTIMATE);
	fftw_execute(p);

	Mat Resource(image.size(), CV_32FC1);
	Mat Imsource(image.size(), CV_32FC1);
	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			*Resource.ptr<float>(j, i) = out[i + j*image.cols][0];//實部
			*Imsource.ptr<float>(j, i) = out[i + j*image.cols][1];//虛部
		}
	}
	
	Mat Redest(image.size(), CV_32FC1);
	Mat Imdest(image.size(), CV_32FC1);
	fftshift(Resource, Redest);
	fftshift(Imsource, Imdest);
	
	Mat absImage(image.size(), CV_32FC1);
	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			*absImage.ptr<float>(j, i) = sqrt(pow(*Redest.ptr<float>(j, i), 2) + pow(*Imdest.ptr<float>(j, i), 2));
		}
	}
	
	
	absImage += Scalar::all(1);
	Mat logImage(image.size(), CV_32FC1);
	log(absImage, logImage);
	//SaveData(logImage);
	double min = 0.0, max = 0.0;
	minMaxLoc(logImage, &min, &max);
	double scale = 255/(max-min);
	double shift = -min*scale;
	Mat myImage(image.size(), CV_8UC1);
	convertScaleAbs(logImage, myImage, scale, shift);
	imwrite("C:\\Users\\Tony\\Desktop\\lenaCopy.bmp", myImage);
}

高低通濾波：

void testOne()
{
	int  i;
	fftw_complex*din, *out;
	fftw_plan p, backp;

	Mat image = imread("C:\\Users\\Tony\\Desktop\\blur.bmp", CV_LOAD_IMAGE_GRAYSCALE);
	din = (fftw_complex *)fftw_malloc(sizeof(fftw_complex)*image.cols*image.rows);
	out = (fftw_complex *)fftw_malloc(sizeof(fftw_complex)*image.cols*image.rows);


	Mat floatImage(image.size(), CV_32FC1);
	image.convertTo(floatImage, CV_32FC1);
	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			din[i + j*image.cols][0] = *floatImage.ptr<float>(j, i);
			din[i + j*image.cols][1] = 0.0;
		}
	}
	//forward fft
	p = fftw_plan_dft_2d(image.rows, image.cols, din, out, FFTW_FORWARD, FFTW_ESTIMATE);
	fftw_execute(p);

	
	//圖像頻譜中心化
	Mat Resource(image.size(), CV_32FC1);
	Mat Imsource(image.size(), CV_32FC1);//虛部
	Mat Redest(image.size(), CV_32FC1);
	Mat Imdest(image.size(), CV_32FC1);//虛部
	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			*Resource.ptr<float>(j, i) = out[i + j*image.cols][0];//實部
			*Imsource.ptr<float>(j, i) = out[i + j*image.cols][1];//虛部
		}
	}


	fftshift(Resource, Redest);
	fftshift(Imsource, Imdest);//虛部



	//圖像頻譜乘以不通的數據,構建濾波
	vector<double>data;
	HPF_Fliter(data, image.cols, image.rows, 10);
	//LPF_Fliter(data, image.cols, image.rows, 100);
	Mat filterRe(image.size(), CV_32FC1);
	Mat filterIm(image.size(), CV_32FC1);//虛部
	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			*filterRe.ptr<float>(j, i) = *Redest.ptr<float>(j, i) * data.at(j*image.cols + i);//實部
			*filterIm.ptr<float>(j, i) = *Imdest.ptr<float>(j, i) * data.at(j*image.cols + i);//虛部
		 }
	}




	//圖像頻譜逆中心化
	Mat NotCenterRedest(image.size(), CV_32FC1);
	Mat NotCenterImdest(image.size(), CV_32FC1);//虛部
	ifftShift(filterRe, NotCenterRedest);
	ifftShift(filterIm, NotCenterImdest);//虛部


	//重新構造複數，傅里葉反變換
	fftw_complex *spectrum = (fftw_complex *)fftw_malloc(sizeof(fftw_complex)*image.cols*image.rows);
	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			spectrum[j*image.cols + i][0] = *NotCenterRedest.ptr<float>(j, i);//實部
			spectrum[j*image.cols + i][1] = *NotCenterImdest.ptr<float>(j, i);//虛部
		}
	}

	

	//傅里葉反變換
	fftw_complex *result = (fftw_complex *)fftw_malloc(sizeof(fftw_complex)*image.cols*image.rows);
	backp = fftw_plan_dft_2d(image.rows, image.cols, spectrum, result, FFTW_BACKWARD, FFTW_ESTIMATE);
	fftw_execute(backp);
	int size = image.cols*image.rows;

	Mat IvsResource(image.size(), CV_32FC1, Scalar::all(0));
	//Mat IvsImsource(image.size(), CV_32FC1, Scalar::all(0));//虛部
	//Mat ifftImage(image.size(), CV_32FC1, Scalar::all(0));
	Mat myImage(image.size(), CV_8UC1);
	for (size_t j = 0; j < image.rows; j++)
	{
		for (size_t i = 0; i < image.cols; i++)
		{
			*IvsResource.ptr<float>(j, i) = result[i + j*image.cols][0] / size;//實部
			//*IvsImsource.ptr<float>(j, i) = result[i + j*image.cols][1] / size;//虛部
			//*ifftImage.ptr<float>(j, i) = sqrt(pow(result[i + j*image.cols][0], 2) + pow(result[i + j*image.cols][1], 2));
			*myImage.ptr<byte>(j, i) = cvRound(abs(*IvsResource.ptr<float>(j, i)));//實部
		}
	}
	//SaveData(IvsResource);
	imwrite("C:\\Users\\Tony\\Desktop\\Copy.bmp", myImage);

	Mat gammaImage(image.size(), CV_8UC1);
	GammaCorrection(myImage, gammaImage, 0.3);

	//釋放資源
	fftw_destroy_plan(p);
	fftw_destroy_plan(backp);
	fftw_free(din);
	fftw_free(out);
	fftw_free(result);
}