VC++使用CImage在内存中Bmp转换Jpeg图片

unsigned  long  BMP2JPEG( char * pUnZipData,unsigned  long  ulUnZipDataLen, char ** pBuffer)

{

     unsigned  long  ulBufferLen = 0;

     HGLOBAL  hGlobal = GlobalAlloc(GMEM_MOVEABLE, ulUnZipDataLen); 

     void * pData = GlobalLock(hGlobal); 

     memcpy (pData, pUnZipData, ulUnZipDataLen); 

     GlobalUnlock(hGlobal); 

     IStream* pStream = NULL; 

     if (CreateStreamOnHGlobal(hGlobal, TRUE,  & pStream) == S_OK) 

     {

         CImage image; 

         if  (SUCCEEDED(image.Load(pStream))) 

         {

             IStream* pOutStream = NULL; 

             if (CreateStreamOnHGlobal(NULL, TRUE,  & pOutStream) == S_OK) 

             {

                 image.Save(pOutStream, Gdiplus::ImageFormatJPEG);

                 HGLOBAL  hOutGlobal= NULL;

                 GetHGlobalFromStream(pOutStream,&hOutGlobal);

                 LPBYTE  pBits= ( LPBYTE )GlobalLock(hOutGlobal);

                 ulBufferLen =( DWORD )GlobalSize(pBits);

                 *pBuffer =  new  char [ulBufferLen];

                 memcpy (*pBuffer, pBits, ulBufferLen);

                 

                 GlobalUnlock(hOutGlobal);

                 pOutStream->Release();

             }

         }  

         pStream->Release();      

     }  

     GlobalFree(hGlobal); 

     return  ulBufferLen;

}