GetDIBits 遍历位图 获取像素的颜色值（RGB）

GetDIBits 遍历位图 获取像素的颜色值（RGB）




CBitmap m_bmp;
//根据位图资源导入之后的ID来获得位图
m_bmp.LoadBitmap(IDB_BITMAP_ORIGIN);


接下来就是通过GetDIBits函数来对位图的像素进行遍历，获取RGB

	BITMAP bm;
	m_bmp.GetBitmap(&bm);

	int nbyte = bm.bmBitsPixel / 8;

	BITMAPINFO bi;  
	bi.bmiHeader.biSize = sizeof(bi.bmiHeader);  
	bi.bmiHeader.biWidth = bm.bmWidth;  
	bi.bmiHeader.biHeight = -bm.bmHeight;  
	bi.bmiHeader.biPlanes = 1;  
	bi.bmiHeader.biBitCount = bm.bmBitsPixel;   
	bi.bmiHeader.biCompression = BI_RGB;   
	bi.bmiHeader.biSizeImage = bm.bmWidth * bm.bmHeight * nbyte; 
	bi.bmiHeader.biClrUsed = 0;  
	bi.bmiHeader.biClrImportant = 0;  

	// 获取位图数据  
	HDC hdc = ::GetDC(NULL);  
	BYTE* pBits = (BYTE*)new BYTE[bm.bmWidth * bm.bmHeight * nbyte];  
	::ZeroMemory(pBits, bm.bmWidth * bm.bmHeight * nbyte);  
	if (!::GetDIBits(hdc, m_bmp, 0, bm.bmHeight, pBits, &bi, DIB_RGB_COLORS))  
	{  
		delete pBits;  
		pBits = NULL;  
	} 
	for (int i = 0;i < bm.bmWidth;++i)
	{
		for (int j = 0;j < bm.bmHeight;++j)
		{
			BYTE r = pBits[i * nbyte + j * bm.bmWidthBytes + 2];
			BYTE g = pBits[i * nbyte + j * bm.bmWidthBytes + 1];
			BYTE b = pBits[i * nbyte + j * bm.bmWidthBytes+ 0];
			//这里就可以做我们处理了
		}
	}

	delete pBits;  
	pBits = NULL;