C / C++ / MFC

<br />
<br />
	CFile dibFile(_T("BITMAP1.bmp"), CFile::modeRead);<br />
	<br />
	<br />
	//open file<br />
<br />
	//create memory for the file header<br />
<br />
	BITMAPFILEHEADER bmpFileHead;<br />
	<br />
	//read the header into memory<br />
<br />
	if(!dibFile.Read((void*)&bmpFileHead, sizeof(BITMAPFILEHEADER)))<br />
		AfxMessageBox("Read failed.");<br />
<br />
	<br />
	//check to make sure the file is a valid bitmap <br />
<br />
	if(bmpFileHead.bfType == ((WORD) ('M' << 8) | 'B'))<br />
	{<br />
		//need the length of the file for further processing<br />
		<br />
		DWORD fileLength = dibFile.GetLength();<br />
				<br />
		//take the size of the header away from the length, we already have the header in memory<br />
		<br />
		DWORD size = fileLength - sizeof(BITMAPFILEHEADER);<br />
				<br />
		//create a pointer to the bitmap data as a chunk of memory<br />
		<br />
		BYTE* pDib = (BYTE*)malloc(size);<br />
		if(!pDib)<br />
			AfxMessageBox("Allocation failed");<br />
			<br />
		//Create second pointer so we have somewhere to reverse the data<br />
		BYTE* pTest = (BYTE*)malloc(size);<br />
		if(!pTest)<br />
			AfxMessageBox("Allocation failed");<br />
<br />
		//read the data into the array<br />
		<br />
		dibFile.Read((void*)pDib, size);<br />
		dibFile.Close();<br />
<br />
		//The following structs contain display information about the bitmap,<br />
		//so we read into them for use later<br />
<br />
		//fill the BITMAPINFO struct from the file data<br />
	<br />
		BITMAPINFO* pBmpInfo = (BITMAPINFO*)pDib;<br />
	<br />
		<br />
		//fill the BITMAPINFOHEADER struct from the file<br />
	<br />
		BITMAPINFOHEADER* pBmpInfoHead = (BITMAPINFOHEADER*) pDib;<br />
	<br />
		<br />
		//fill the RGBQUAD struct from the file<br />
	<br />
		RGBQUAD* pRGB = (RGBQUAD*)(pDib + pBmpInfoHead->biSize);<br />
<br />
<br />
		//determine the number of colors used in the bitmap<br />
		/*<br />
		int numColors;<br />
		if((pBmpInfoHead->biClrUsed == 0) && (pBmpInfoHead->biBitCount < 9))<br />
		{<br />
			switch(pBmpInfoHead->biBitCount)<br />
			{<br />
			case 1: numColors = 2; break;<br />
			case 4: numColors = 16; break;<br />
			case 8: numColors = 256;<br />
			}<br />
		}<br />
		else<br />
			numColors = (int)pBmpInfoHead->biClrUsed;<br />
<br />
		if(pBmpInfoHead->biClrUsed == 0)<br />
			pBmpInfoHead->biClrUsed = numColors;<br />
<br />
		<br />
		//now that we have the number of colors we can determine where the actual image <br />
		//data starts, and read it into an array so we can work with it<br />
<br />
		DWORD clrTable = numColors * sizeof(RGBQUAD);<br />
		BYTE* pData = pDib + pBmpInfoHead->biSize + clrTable;<br />
<br />
		if(pBmpInfoHead->biSizeImage == 0)<br />
		{<br />
			DWORD height = pBmpInfoHead->biHeight;<br />
			DWORD width = pBmpInfoHead->biWidth;<br />
<br />
			pBmpInfoHead->biSize = height * width;<br />
		}<br />
		*/<br />
		//reverse the data to flip the image.<br />
		//using 44 as first subscript to read, to offset the BITMAPINFO <br />
		int s = 0;<br />
		for(unsigned g = 44;g < size;g++)<br />
		{<br />
			pTest[s] = pDib[g];<br />
			s++;<br />
		}<br />
		//create and write to the new file<br />
		CFile wFile(_T("test.bmp"), CFile::modeWrite | CFile::modeCreate | CFile::typeBinary);<br />
<br />
		wFile.Write((void*)&bmpFileHead, sizeof(BITMAPFILEHEADER));<br />
		<br />
		wFile.Write((void*)pDib, sizeof(BITMAPINFO));<br />
		<br />
		wFile.Write((void*)pTest, size);<br />
<br />
		wFile.Close();<br />
		<br />
		//clean up<br />
<br />
		free(pTest);<br />
		free(pDib);<br />
	}<br />