数字图像处理——图像平滑（均值滤波）

void CWvltDoc::OnFilterSmoothmean()//均值滤波
{
	LPBITMAPFILEHEADER lpBitmapFileHeader = (LPBITMAPFILEHEADER)m_pBitmap;
	LPBITMAPINFOHEADER lpBitmapInfoHeader = (LPBITMAPINFOHEADER)(m_pBitmap + 14);
	unsigned char *lpData = m_pBitmap + lpBitmapFileHeader->bfOffBits;
	unsigned long biHeight = lpBitmapInfoHeader->biHeight;
	unsigned long biWidth = lpBitmapInfoHeader->biWidth;  
	unsigned long biAlign = (biWidth * 3 + 3) / 4 * 4;
	unsigned long bmSize = biHeight * biAlign;
	if (m_pTransfered == NULL)
		m_pTransfered = (unsigned char*)malloc(bmSize);
	if (m_pTransfered == NULL)
		return;
	//Add the processing code here, which reverses the color of each pixel.
	int x, y, cur;
	for (y = 1; y < (int)biHeight-1; y++)
	{
		for (x = 1; x < (int)biWidth-1; x++)
		{
			cur = y*biAlign + 3 * x;	
			int i,j,sum;
			int data[9];
			for (i = 0; i < 3; i++)//选择G、B、R分量
			{
				sum = 0;
				for (j = 0; j < 9; j++)//3*3模板
				{
					data[j] = lpData[(cur+i)-3*(4-j)];
					sum = sum + data[j];
				} 
				m_pTransfered[cur+i] = (int)(sum/9);
			}
		}
	}
	UpdateAllViews(NULL);//文档被修改后可调用此函数，把文档被修改的信息通知给每个视图.
}

效果图：

处理前

<img src="https://img-blog.csdn.net/20161106112612353?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />

处理后

<img src="https://img-blog.csdn.net/20161106112624588?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />