wvlttrans.cpp

一种图像水印加密算法 该算法抗攻击性强 安全性高 可以直接运行

						LH1[i][j] = m_WvltCoeff[i][j];
					}
					else
					{
						HH1[i][j] = m_WvltCoeff[i][j];
					}
				}
			}
			
		}
	}

}


//求子带幅值最大的系数,返回幅值最大系数的绝对值,幅值为实部与虚部的平方和的开方，此处直接取系数的绝对值
float CWvltTrans::MaxvalOfBlock(float** Block)
{
	float MaxCoeff = 0;
	for(int i=0; i<biHeight; i++)
	{
		for(int j=0; j<biWidth; j++)
		{
			if(abs(Block[i][j]) > MaxCoeff)//求绝对值最大的系数
				MaxCoeff = abs(Block[i][j]);
		}
	}
	return MaxCoeff;

}


float CWvltTrans::abs(float a)
{
	return( a>=0 ? a : -a );
}

/************************************************************************************
*　功能：选择要加载水印的系数，结果存到CoeffChoosed[][]数组中，
*　mlength：水印信息长度
*　说明：将水印加载到3级小波变换后除LL3外的所有子带中。过程：1、对每天子带j,设初始阈值为
*　      Tj=0.75|Max(Xj)|,选择幅值大小Tj的系数；2、若系数总个数少于MarkLength，则更新阈值Tj=0.75Tj,
*　      再重新待选择，直到找到mlength个系数，　此方法各子带嵌入水印的概率相等
**************************************************************************************/
void CWvltTrans::ChooseCoeffByLocalThreshold()//此函数没被用
{
	CoeffPartition();//将系数分割成各子带
	int count=0;//计数选出的系数个数
	int i,j;
	float TLH1 = MaxvalOfBlock(LH1);
	float TLH2 = MaxvalOfBlock(LH2);
	float TLH3 = MaxvalOfBlock(LH3);
	float THL1 = MaxvalOfBlock(HL1);
	float THL2 = MaxvalOfBlock(HL2);
	float THL3 = MaxvalOfBlock(HL3);
	float THH1 = MaxvalOfBlock(HH1);
	float THH2 = MaxvalOfBlock(HH2);
	float THH3 = MaxvalOfBlock(HH3);
	float MaxCoeffLL1 = MaxvalOfBlock(LL1);
    //选出mlength个系数
	while(count< MarkLength)
	{	

		//初始阈值
		TLH1 = 0.75*TLH1;
		TLH2 = 0.75*TLH2;
		TLH3 = 0.75*TLH3;
		THL1 = 0.75*THL1;
		THL2 = 0.75*THL2;
		THL3 = 0.75*THL3;
		THH1 = 0.75*THH1;
		THH2 = 0.75*THH2;
		THH3 = 0.75*THH3;

		count = 0;//改变阈值后计数器清0
		//选定的系数数组重新初始化
		for(i=0; i<biHeight; i++)
		{
			for(j=0; j<biWidth; j++)
			{
				CoeffChoosed[i][j] = 0.0;

			}
		}
        //从各子带中选择幅值大于本子带阈值的系数
		for(i=0; i<biHeight; i++)
		{
			for(j=0; j<biWidth; j++)
			{
				if(abs(LH1[i][j])>TLH1 && count<MarkLength)
				{
					CoeffChoosed[i][j] = LH1[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(LH2[i][j])>TLH2 && count<MarkLength)
				{
					CoeffChoosed[i][j] = LH2[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(LH3[i][j])>TLH3 && count<MarkLength)
				{
					CoeffChoosed[i][j] = LH3[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(HL1[i][j])>THL1 && count<MarkLength)
				{
					CoeffChoosed[i][j] = HL1[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(HL2[i][j])>THL2 && count<MarkLength)
				{
					CoeffChoosed[i][j] = HL2[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(HL3[i][j])>THL3 && count<MarkLength)
				{
					CoeffChoosed[i][j] = HL3[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(HH1[i][j])>THH1 && count<MarkLength)
				{
					CoeffChoosed[i][j] = HH1[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(HH2[i][j])>THH2 && count<MarkLength)
				{
					CoeffChoosed[i][j] = HH2[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}
				if(abs(HH3[i][j])>THH2 && count<MarkLength)
				{
					CoeffChoosed[i][j] = HH3[i][j];//将此值保存到选定系数数组中
					count++;
					if(count = MarkLength)
						break;
				}

			}

		}
	}
}
/************************************************************************************
*　功能：根据整体阈值选择要加载水印的系数，结果存到CoeffChoosed[][]数组中,CoeffChoosed[][]
         中为绝对值大于阈值的系数
*　mlength：水印信息长度
*　说明：将水印加载到3级小波变换后除LL3外的所有子带中。过程：1、计算每个子带的阈值为
*　      Tj=0.75|Max(Xj)|,初始全局阈值Ti=Max(Tj)，选择幅值大于Tj的系数；2、若系数总个
*        数少于mlength，则更新阈值Ti=0.5Ti,*　      再重新待选择，直到找到MarkLength个系数，
*      　此方法各子带嵌入水印的概率相等
**************************************************************************************/
/*
void CWvltTrans::ChooseCoeffByWholeThreshold()
{
	CoeffPartition();//将系数分割成各子带
	int count=0;//计数选出的系数个数
	int i,j;
	float Threshold = 0.0;
	float TLH1 = 0.75*MaxvalOfBlock(LH1);
	float TLH2 = 0.75*MaxvalOfBlock(LH2);
	float TLH3 = 0.75*MaxvalOfBlock(LH3);
	float THL1 = 0.75*MaxvalOfBlock(HL1);
	float THL2 = 0.75*MaxvalOfBlock(HL2);
	float THL3 = 0.75*MaxvalOfBlock(HL3);
	float THH1 = 0.75*MaxvalOfBlock(HH1);
	float THH2 = 0.75*MaxvalOfBlock(HH2);
	float THH3 = 0.75*MaxvalOfBlock(HH3);
	//初始阈值为各子带阈值的最大值
	if(TLH1>Threshold)
	{
		Threshold = TLH1;
	}
	if(TLH2>Threshold)
	{
		Threshold = TLH2;
	}
	if(TLH3>Threshold)
	{
		Threshold = TLH3;
	}
	if(THL1>Threshold)
	{
		Threshold = THL1;
	}
	if(THL2>Threshold)
	{
		Threshold = THL2;
	}
	if(THL3>Threshold)
	{
		Threshold = THL3;
	}
	if(THH1>Threshold)
	{
		Threshold = THH1;
	}
	if(THH2>Threshold)
	{
		Threshold = THH2;
	}
	if(THH3>Threshold)
	{
		Threshold = THH3;
	}
	

    //选出MarkLength个系数
	while(count < MarkLength)
	{
		count =0;//如当前阈值选不出MarkLength个系数，修改阈值进行下一次选择时计数器清0
		//重新初始化选定的系数数组的各元素为0
		for(i=0; i<biHeight; i++)
		{
			for(j=0; j<biWidth; j++)
			{
				CoeffChoosed[i][j] = 0.0;
			}
		}
		for(i=0; i<biHeight; i++)
		{
			for(j=0; j<biWidth; j++)
			{
				if(abs(LH1[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = LH1[i][j];//将此值保存到选定系数数组中
					count++;
					
				}
				if(abs(HL1[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = HL1[i][j];//将此值保存到选定系数数组中
					count++;
					
				}
				if(abs(HH1[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = HH1[i][j];//将此值保存到选定系数数组中
					count++;
					
				}
				if(abs(LH2[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = LH2[i][j];//将此值保存到选定系数数组中
					count++;
					
				}
				if(abs(HL2[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = HL2[i][j];//将此值保存到选定系数数组中
					count++;
					
				}
				if(abs(HH2[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = HH2[i][j];//将此值保存到选定系数数组中
					count++;
					
				}
				if(abs(LH3[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = LH3[i][j];//将此值保存到选定系数数组中
					count++;
					
				}				
				
				if(abs(HL3[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = HL3[i][j];//将此值保存到选定系数数组中
					count++;
					
				}				
				
				if(abs(HH3[i][j])>Threshold && count<MarkLength)
				{	
					if(count == MarkLength)
						break;
					CoeffChoosed[i][j] = HH3[i][j];//将此值保存到选定系数数组中
					count++;
				
				}
            
			}//end for

		}//end for
		if(count < MarkLength)
		{
			Threshold = 0.5*Threshold;//修改阈值
		}


	}//end while

}
*/
void CWvltTrans::ChooseCoeffByWholeThreshold()
{
	CoeffPartition();//将系数分割成各子带
	int count=0;//计数选出的系数个数
	int i,j;
	float Threshold = 0.0;
	float TLH1 = 0.75*MaxvalOfBlock(LH1);
	float TLH2 = 0.75*MaxvalOfBlock(LH2);
	float TLH3 = 0.75*MaxvalOfBlock(LH3);
	float THL1 = 0.75*MaxvalOfBlock(HL1);
	float THL2 = 0.75*MaxvalOfBlock(HL2);
	float THL3 = 0.75*MaxvalOfBlock(HL3);
	float THH1 = 0.75*MaxvalOfBlock(HH1);
	float THH2 = 0.75*MaxvalOfBlock(HH2);
	float THH3 = 0.75*MaxvalOfBlock(HH3);
	//初始阈值为各子带阈值的最大值
	if(TLH1>Threshold)
	{
		Threshold = TLH1;
	}
	if(TLH2>Threshold)
	{
		Threshold = TLH2;
	}
	if(TLH3>Threshold)
	{
		Threshold = TLH3;
	}
	if(THL1>Threshold)
	{
		Threshold = THL1;
	}
	if(THL2>Threshold)
	{
		Threshold = THL2;
	}
	if(THL3>Threshold)
	{
		Threshold = THL3;
	}
	if(THH1>Threshold)
	{
		Threshold = THH1;
	}
	if(THH2>Threshold)
	{
		Threshold = THH2;
	}
	if(THH3>Threshold)
	{
		Threshold = THH3;
	}	

    //选出MarkLength个系数
	while(count < MarkLength)
	{
		count =0;//如当前阈值选不出MarkLength个系数，修改阈值进行下一次选择时计数器清0
		//重新初始化选定的系数数组的各元素为0
		for(i=0; i<biHeight; i++)
		{
			for(j=0; j<biWidth; j++)
			{
				CoeffChoosed[i][j] = 0.0;
			}
		}
		for(i=0; i<biHeight; i++)
		{
			for(j=0; j<biWidth; j++)
			{
				if(abs(LH1[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					count++;//找到一个选定系数
					CoeffChoosed[i][j] = LH1[i][j];//将此值保存到选定系数数组中
					//将此位置坐标二值对保存
					//pic.LoadPlace[count].first = i;
					//pic.LoadPlace[count].second = j;				
					
				}
				if(abs(HL1[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					count++;
					CoeffChoosed[i][j] = HL1[i][j];//将此值保存到选定系数数组中
					//将此位置坐标二值对保存
					//pic.LoadPlace[count].first = i;
				//	pic.LoadPlace[count].second = j;
					
					
				}
				if(abs(HH1[i][j])>Threshold && count<MarkLength)
				{
					if(count == MarkLength)
						break;
					count++;
					CoeffChoosed[i][j] = HH1[i][j];//将此值保存到选定系数数组中
					//将此位置坐标二值对保存
					//pic.LoadPlace[count].first = i;
					//pic.LoadPlace[count].second = j;