保存內存數據爲jpg圖片：先將數據加上bmp頭，然後轉換爲opencv格式並保存1

 此處圖片大小爲：width*height

1.將圖像數據加上bmp頭

unsigned char* ProcessFile::GetBmp32(PBYTE pOCTData, int nColorBits, int iWidth, int iHeight)
{
	
	unsigned char*	pszBmp32 = NULL;

	BITMAPFILEHEADER fileHeader;
	fileHeader.bfType = 'MB';
	fileHeader.bfReserved1 = 0;
	fileHeader.bfReserved2 = 0;
	fileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
	fileHeader.bfSize = fileHeader.bfOffBits + iWidth * iHeight * (nColorBits / 8);

	pszBmp32 = new unsigned char[fileHeader.bfSize];
	unsigned char * pHead = pszBmp32;
	memcpy(pHead, &fileHeader, sizeof(BITMAPFILEHEADER));
	pHead += sizeof(BITMAPFILEHEADER);

	BITMAPINFOHEADER bih;
	memset(&bih, 0, sizeof(bih));
	bih.biSize = sizeof(bih);
	bih.biWidth = iWidth;
	bih.biHeight = iHeight;
	bih.biPlanes = 1;
	bih.biBitCount = nColorBits;

	memcpy(pHead, &bih, sizeof(BITMAPINFOHEADER));
	pHead += sizeof(BITMAPINFOHEADER);

	memcpy(pHead, pOCTData, iWidth * iHeight * (nColorBits / 8));

	return pszBmp32;
}

2.轉換爲opencv格式並保存：

int ProcessFile::SaveBitmapToFileEx(BYTE *pBuffer, int nColorBits, CString m_szFileName, int nWidth, int nHeight)
{
	unsigned char * pszBmp32 = GetBmp32(pBuffer,  nColorBits, nWidth, nHeight);
	cv::Mat mt;
	ProcessFile::DecodeIM(pszBmp32, mt);
	//cv::imread(szBmpPath);
	USES_CONVERSION;
	char* szFilePath = W2A(m_szFileName);
	cv::imwrite(szFilePath, mt);
	delete pszBmp32;
	return 0;
}