c++ 图片加水印

#include "stdafx.h"
#include "gdiplus.h"
#include "atlimage.h"
using namespace Gdiplus;
#include <string>
using namespace std;
GdiplusStartupInput gSDKdiplusStartupInput = 0;
ULONG_PTR gSDKdiplusToken = 0;

int GetEncoderClsidOwn(const WCHAR* format, CLSID* pClsid)
{
 UINT  num = 0;          // number of image encoders
 UINT  size = 0;         // size of the image encoder array in bytes

 ImageCodecInfo* pImageCodecInfo = NULL;

 GetImageEncodersSize(&num, &size);
 if(size == 0)
  return -1;  // Failure

 pImageCodecInfo = (ImageCodecInfo*)(malloc(size));
 if(pImageCodecInfo == NULL)
  return -1;  // Failure

 GetImageEncoders(num, size, pImageCodecInfo);

 for(UINT j = 0; j < num; ++j)
 {
  if( wcscmp(pImageCodecInfo[j].MimeType, format) == 0 )
  {
   *pClsid = pImageCodecInfo[j].Clsid;
   free(pImageCodecInfo);
   return j;  // Success
  }   
 }

 free(pImageCodecInfo);
 return -1;  // Failure
}

void main()

{

GdiplusStartup(&gSDKdiplusToken, &gSDKdiplusStartupInput, NULL);

 USES_CONVERSION;
  FontFamily  fontFamily(L"Arial");
  float fontSize = 12*(float)abs(2);
  Font        font(&fontFamily, fontSize, FontStyleBold, UnitPixel);
  SolidBrush  blackBrush(Color(0, 0, 0));
  PointF pointF(1, 1);
  CLSID encoderClsid;
  GetEncoderClsidOwn(L"image/jpeg", &encoderClsid);
  string filename;
  WCHAR wfilename[MAX_PATH];
  for(int i=0;i<20;i++)
  {
   filename = "out_";
   char str[4];
   itoa(i, str, 10);
   filename = filename+str;
   filename=filename+".jpg";
   memset(wfilename,0,MAX_PATH);
   wcscpy(wfilename, T2W(filename.c_str()) );
   Bitmap bmp(L"sample.jpg");
   Graphics g(&bmp);
   g.DrawString(wfilename, -1, &font, pointF, &blackBrush);
   bmp.Save(wfilename,&encoderClsid);
   printf("%d\n",i);
  }

GdiplusShutdown(gSDKdiplusToken);

}