Baumer工业相机堡盟相机中的JPEG图像压缩相机如何通过BGAPI SDK和OpenCV的Mat进行图像转换（C++）

#pragma comment(lib, "opencv_world341.lib")
#pragma comment(lib, "opencv_world341d.lib")

void BGAPI2CALL BufferHandler( void * callBackOwner, Buffer * pBufferFilled )
{
  CGigeDemoDlg* pDlg = (CGigeDemoDlg*)callBackOwner;
  unsigned char* imagebuffer = NULL;
  USES_CONVERSION;
  try
  {
  if(pBufferFilled == NULL)
  {
  }
  else if(pBufferFilled->GetIsIncomplete() == true)
  {
    // queue buffer again
    pBufferFilled->QueueBuffer();
  }
  else
  {
    //std::cout << " Image " << std::setw(5) << pBufferFilled->GetFrameID() << " received in memory address " << pBufferFilled->GetMemPtr() << std::endl;
    int width = 0, height = 0;
    width = (int)pBufferFilled->GetWidth();
    height = (int)pBufferFilled->GetHeight();
    #pragma region 内存 JPEG 数据转换为 opencv 里的 jpeg 数据
    char* image_buffer = (char *)((bo_uint64)(pBufferFilled->GetMemPtr()) + pBufferFilled->GetImageOffset());
    int image_length = (int)pBufferFilled->GetImageLength();
    cv::Mat * imgbuf = new cv::Mat(cv::Size(1, image_length), CV_8UC1, (char *)image_buffer);
    convert from JPEG to Bitmap
    cv::Mat imOriginal = cv::imdecode(*imgbuf, CV_LOAD_IMAGE_GRAYSCALE);
    cv::Mat* imgbuf2 = new cv::Mat((int)pBufferFilled->GetHeight(),(int)pBufferFilled->GetWidth(),CV_8UC1,(char *)pBufferFilled->GetMemPtr());
    cv::Mat imOriginal2 = cv::imdecode(*imgbuf2, CV_LOAD_IMAGE_GRAYSCALE);
    CTime time = CTime::GetCurrentTime(); 
    CString strtime;
    strtime.Format(_T("\\%4d%2d%2d%2d%2d%2d"),time.GetYear(),time.GetMonth(),time.GetDay(),time.GetHour(),time.GetMinute(),time.GetSecond());
    #pragma region//通过获取的Mat图片进行保存
    CString strpath2 =_T("C:\\Users\\BAUMER\\Desktop\\")+strtime+"Mat.jpg";
    cv::String cvstrpath = W2A(strpath2);
    cv::imwrite(cvstrpath,*imgbuf2);
    cv::imwrite(cvstrpath,imOriginal);
    #pragma endregion
    #pragma endregion
    #pragma region//方法一：获取开启JPEG模式后内存数据中有效的像素指针
    size_t jpeg_start_offset = GetStartOfJPEGData(reinterpret_cast<const char*>(pBufferFilled->GetMemPtr()),pBufferFilled->GetMemSize());
    size_t jpeg_end_offset = GetEndOfJPEGData(reinterpret_cast<const char*>(pBufferFilled->GetMemPtr()),jpeg_start_offset,pBufferFilled->GetMemSize());
    #pragma endregion
    #pragma region//方法二：获取开启JPEG模式后内存数据中有效的像素指针
    size_t jpeg_start_offset2 = pBufferFilled->GetImageOffset();
    size_t jpeg_end_offset2 = jpeg_start_offset2+ pBufferFilled->GetImageLength();
    #pragma endregion
    //方法【1】原图像格式转换[Mat] 转 unsigned char*]
    unsigned char *imagebuffer2 = imOriginal2.data;
    imagebuffer = (BYTE*)((bo_int64)pBufferFilled->GetMemPtr()+pBufferFilled->GetImageOffset());
    //imagebuffer = reinterpret_cast<BYTE*>(pBufferFilled->GetMemPtr()) + jpeg_start_offset,(jpeg_end_offset + 1) - jpeg_start_offset;
    if(pDlg->m_bSaveImage &&!pDlg->m_strDirectory.IsEmpty())
    {
    //CTime time = CTime::GetCurrentTime(); 
    //CString strtime;
    //strtime.Format(_T("\\%4d%2d%2d%2d%2d%2d"),time.GetYear(),time.GetMonth(),time.GetDay(),time.GetHour(),time.GetMinute(),time.GetSecond());
    //CString  strpath = pDlg->m_strDirectory+strtime+".jpg";
    //#pragma region//通过流文件的方式将 JPEG 的数据保存为 jpg 文件，但是这种操作是无法将数据转为内存bitmap 的，转换需要第三方软件如 opencv
    //std::ofstream outfile;
    //outfile.open(strpath, std::ios_base::binary);
    //outfile.write(reinterpret_cast<const char*>(pBufferFilled->GetMemPtr()) + jpeg_start_offset2,jpeg_end_offset2 - jpeg_start_offset2);
    //#pragma endregion
    //#pragma region//通过获取的Mat图片进行保存
    //CString strpath2 = pDlg->m_strDirectory+strtime+"Mat.jpg";
    //cv::String cvstrpath = W2A(strpath2);
    //cv::imwrite(cvstrpath,imOriginal);
    //#pragma endregion
    //#pragma region//通过原始JPEG数据进行保存，会有灰色条纹
    //CString  strpath3 = pDlg->m_strDirectory+strtime+"2.jpg";
    //pDlg->SaveImage(strpath3, imagebuffer,width,height);
    //pDlg->m_bSaveImage = false;
    //#pragma region
    }
    Gdiplus::Rect rc = Gdiplus::Rect(0,0,width,height);
    if(pDlg->m_pBitmap == NULL)
    {
    pDlg->m_pBitmap = new Gdiplus::Bitmap(width,height,PixelFormat8bppIndexed);
    }
    Gdiplus::BitmapData lockedbits;
    Gdiplus::ColorPalette * pal = (Gdiplus::ColorPalette*)new BYTE[sizeof(Gdiplus::ColorPalette)+255*sizeof(Gdiplus::ARGB)];
    pal->Count=256;
    for(UINT i=0;i<256;i++)
    {
    UINT color=i*65536+i*256+i;
    color= color|0xFF000000;
    pal->Entries[i]=color;
    }
    pDlg->m_pBitmap->SetPalette(pal);
    Gdiplus::Status ret = pDlg->m_pBitmap->LockBits(&rc,Gdiplus::ImageLockModeWrite,PixelFormat8bppIndexed,&lockedbits);
    BYTE* pixels = (BYTE*)lockedbits.Scan0;
    BYTE* src = (BYTE*)imagebuffer2;
    for (int row = 0; row < height; ++row) 
    {
    CopyMemory(pixels, src, lockedbits.Stride);
    pixels += width;
    src += width;
    }
    pDlg->m_pBitmap->UnlockBits(&lockedbits);
    HDC hDC = ::GetDC(pDlg->m_stcPicture.m_hWnd);
    Gdiplus::Graphics GdiplusDC(hDC);
    CRect rcControl;
    pDlg->m_stcPicture.GetWindowRect(&rcControl);
    Gdiplus::Rect rtImage(0,0,rcControl.Width(),rcControl.Height());
    GdiplusDC.DrawImage(pDlg->m_pBitmap,rtImage,0,0,width,height, Gdiplus::UnitPixel);
    delete []pal;
    ::ReleaseDC(pDlg->m_stcPicture.m_hWnd,hDC);
    delete pDlg->m_pBitmap ;
    pDlg->m_pBitmap =NULL;
    // queue buffer again
    pBufferFilled->QueueBuffer();
  }
  }
  catch (BGAPI2::Exceptions::IException& ex)
  {
  CString str;
  str.Format(_T("ExceptionType:%s! ErrorDescription:%s in function:%s"),ex.GetType(),ex.GetErrorDescription(),ex.GetFunctionName());
  //MessageBox(str);
  }
  //return;
}