逆滤波处理.txt

walsh变换

//参数说明:
//LPSTR lpDIBBits    - 指向源DIB图像指针
//LONG  lWidth       - 源图像宽度（象素数，必须是4的倍数）
//LONG  lHeight      - 源图像高度（象素数）
/
//函数说明:
//该函数用来对BlurDIB()生成的DIB图像进行复原操作。
BOOL WINAPI RestoreDIB (LPSTR lpDIBBits, LONG lWidth, LONG lHeight)
{
	// 指向源图像的指针
	LPSTR	lpSrc;
	//循环变量
	long i;
	long j;
	//像素值
	unsigned char pixel;
	// 图像每行的字节数
	LONG lLineBytes;
	//用于做FFT的数组
	double *fftSrc,*fftKernel;
	double a,b,c,d;
	//二维FFT的长度和宽度
	unsigned long nn[3];
	//图像归一化因子
	double MaxNum;
	// 计算图像每行的字节数
	lLineBytes = WIDTHBYTES(lWidth * 8);
	double dPower = log((double)lLineBytes)/log(2.0);
	if(dPower != (int) dPower)
	{
		return false;
	}
	dPower = log((double)lHeight)/log(2.0);
	if(dPower != (int) dPower)
	{
		return false;
	}
	fftSrc = new double [lHeight*lLineBytes*2+1];
	fftKernel = new double [lHeight*lLineBytes*2+1];
	nn[1] = lHeight;
	nn[2] = lLineBytes;
	for (j = 0;j < lHeight ;j++)
	{
		for(i = 0;i < lLineBytes ;i++)
		{
			// 指向源图像倒数第j行，第i个象素的指针			
			lpSrc = (char *)lpDIBBits + lLineBytes * j + i;
			
			pixel = (unsigned char)*lpSrc;
			
			fftSrc[(2*lLineBytes)*j + 2*i + 1] = (double)pixel;
			fftSrc[(2*lLineBytes)*j + 2*i + 2] = 0.0;
			
			if(i < 5 && j == 0)
			{
				fftKernel[(2*lLineBytes)*j + 2*i + 1] = 1/5.0;
			}
			else
			{
				fftKernel[(2*lLineBytes)*j + 2*i + 1] = 0.0;
			}
			fftKernel[(2*lLineBytes)*j + 2*i + 2] = 0.0;
		}
	}
	
	//对源图像进行FFT
	fourn(fftSrc,nn,2,1);
	//对卷积核图像进行FFT
	fourn(fftKernel,nn,2,1);
	for (j = 0;j < lHeight ;j++)
	{
		for(i = 0;i < lLineBytes ;i++)
		{
			a = fftSrc[(2*lLineBytes)*j + 2*i + 1];
			b = fftSrc[(2*lLineBytes)*j + 2*i + 2];
			c = fftKernel[(2*lLineBytes)*j + 2*i + 1];
			d = fftKernel[(2*lLineBytes)*j + 2*i + 2];
			if (c*c + d*d > 1e-3)
			{
				fftSrc[(2*lLineBytes)*j + 2*i + 1] = ( a*c + b*d ) / ( c*c + d*d );
				fftSrc[(2*lLineBytes)*j + 2*i + 2] = ( b*c - a*d ) / ( c*c + d*d );
			}
		}
	}
	//对结果图像进行反FFT
	fourn(fftSrc,nn,2,-1);
	
	//确定归一化因子
	MaxNum = 0.0;
	for (j = 0;j < lHeight ;j++)
	{
		for(i = 0;i < lLineBytes ;i++)
		{
			fftSrc[(2*lLineBytes)*j + 2*i + 1] = 
				sqrt(fftSrc[(2*lLineBytes)*j + 2*i + 1] * fftSrc[(2*lLineBytes)*j + 2*i + 1]\
				+fftSrc[(2*lLineBytes)*j + 2*i + 2] * fftSrc[(2*lLineBytes)*j + 2*i + 2]);
			if( MaxNum < fftSrc[(2*lLineBytes)*j + 2*i + 1])
				MaxNum = fftSrc[(2*lLineBytes)*j + 2*i + 1];
		}
	}
	
	//转换为图像
	for (j = 0;j < lHeight ;j++)
	{
		for(i = 0;i < lLineBytes ;i++)
		{
			// 指向源图像倒数第j行，第i个象素的指针			
			lpSrc = (char *)lpDIBBits + lLineBytes * j + i;
			
			*lpSrc = (unsigned char) (fftSrc[(2*lLineBytes)*j + 2*i + 1]*255.0/MaxNum);
		}
	}
	delete fftSrc;
	delete fftKernel;
	// 返回
	return true;
}