bmp to jpg using gdi+

来源：互联网发布：3d算法编辑：程序博客网时间：2024/06/05 07:54

首先得初始化GDI+

#include "GdiPlus.h"
using namespace Gdiplus;
#pragma comment(lib,"gdiplus.lib")

GdiplusStartupInput m_gdiplusStartupInput;
ULONG_PTR m_pGdiToken;

GdiplusStartup(&m_pGdiToken,&m_gdiplusStartupInput,NULL);

bool GetEncoderClsid(const WCHAR* format,CLSID *pClsid)
{
UINT num = 0;
UINT size = 0;
ImageCodecInfo* pImageCodecInfo = NULL;
GetImageEncodersSize(&num,&size);
if (size == 0)
{
return false;
}

pImageCodecInfo = (ImageCodecInfo*)(malloc(size));
if (pImageCodecInfo == NULL)
{
return false;
}

GetImageEncoders(num,size,pImageCodecInfo);
for (UINT i = 0;i < num;i++)
{
  if (wcscmp(pImageCodecInfo[i].MimeType,format) == 0)
  {
   *pClsid = pImageCodecInfo[i].Clsid;
   free(pImageCodecInfo);
   return true;
  }
}
free(pImageCodecInfo);
return false;
}

void BMP2JPG(CString strBMPFile,CString strJPGFile)
{
CLSID encoderClsid;
WCHAR strGuid[39];
if (GetEncoderClsid(L"image/jpeg",&encoderClsid) )
{
StringFromGUID2(encoderClsid,strGuid,39);
}
Image image(strBMPFile.AllocSysString());
image.Save(strJPGFile.AllocSysString(),&encoderClsid,NULL);
}