图片相似度比较

// ImageCmp.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "ImageSimilar.h"
#include <iostream>
#include <Psapi.h>

int _tmain(int argc, _TCHAR* argv[])
{
  ImageSimilar::initGdiPlus();

  HANDLE h = GetCurrentProcess();
  for (int i = 1; i <= 100; ++i)
  {
    PROCESS_MEMORY_COUNTERS mem = { 0 };
    GetProcessMemoryInfo(h, &mem, sizeof(mem));
    int memSize = mem.WorkingSetSize / 1024 * 1024;

    auto start = std::chrono::system_clock::now();

    float val = ImageSimilar::getSimilar("1.png", "2.png");

    auto end = std::chrono::system_clock::now();
    auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
    double cost = double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den;
    std::cout << "val=" << val << " 耗时：" << cost << "秒" << " memSize=" << memSize<< std::endl;
  }

  ImageSimilar::unInitGdiPlus();
  getchar();
  return 0;
}

#include <iostream>
#include <fstream>
#include <string>
#include <chrono>
#include <windows.h>
#include <gdiplus.h>
#pragma comment(lib, "gdiplus.lib")
using namespace Gdiplus;

namespace ImageSimilar
{
  typedef struct tagIStreamBmp
  {
    IStream *pIStream;
    Bitmap *pBitmap;
    tagIStreamBmp()
    {
      pIStream = NULL;
    }
  }SIStreamBmp, *PSIStreamBmp;

  GdiplusStartupInput gdiplusstartupinput;
  ULONG_PTR gdiplustoken;

  void initGdiPlus()
  {
    GdiplusStartup(&gdiplustoken, &gdiplusstartupinput, NULL);
  }

  void unInitGdiPlus()
  {
    GdiplusShutdown(gdiplustoken);
  }

  bool getStreamBmp(SIStreamBmp& iStreamBmp, char* szData, int dataLen)
  {
    HGLOBAL hMemBmp = GlobalAlloc(GMEM_FIXED, dataLen);
    if (hMemBmp == NULL) return false;
    CreateStreamOnHGlobal(hMemBmp, TRUE, &iStreamBmp.pIStream);
    if (iStreamBmp.pIStream == NULL)
    {
      return false;
    }
    BYTE* bData = (BYTE *)GlobalLock(hMemBmp); // 获得内存块首地址
    memcpy(bData, szData, dataLen);
    GlobalUnlock(hMemBmp);

    iStreamBmp.pBitmap = Bitmap::FromStream(iStreamBmp.pIStream);
    
    //GlobalFree(hMemBmp); // 需要释放吗?
    return true;
  }

  int getFileSize(char* szFile)
  {
    size_t size = 0;
    std::ifstream f;
    f.open(szFile, std::ios::binary | std::ios::in);
    if (f.is_open())
    {
      f.seekg(0, std::ios::end);
      size = f.tellg();
      f.close();
    }
    return size;
  }

  float getSimilar2(char* szData1, int dataLen1, char* szData2, int dataLen2)
  {
    if (szData1 == NULL || dataLen1 <= 0) return 0;
    if (szData2 == NULL || dataLen2 <= 0) return 0;

    SIStreamBmp sBmp1;
    SIStreamBmp sBmp2;
    if (!getStreamBmp(sBmp1, szData1, dataLen1)) return 0;
    if (!getStreamBmp(sBmp2, szData2, dataLen2)) return 0;

    if (sBmp1.pBitmap->GetWidth() != sBmp2.pBitmap->GetWidth()) return 0;
    if (sBmp1.pBitmap->GetHeight() != sBmp2.pBitmap->GetHeight()) return 0;

    Gdiplus::Color c1;
    Gdiplus::Color c2;

    // 逐个像素比较
    int xMax = sBmp1.pBitmap->GetWidth();
    int yMax = sBmp1.pBitmap->GetHeight();
    int same = 0;
    for (size_t x = 0; x < xMax; x++)
    {
      for (size_t y = 0; y < yMax; y++)
      {
        sBmp1.pBitmap->GetPixel(x, y, &c1);
        sBmp2.pBitmap->GetPixel(x, y, &c2);
        if (c1.GetValue() == c2.GetValue())
        {
          same += 1;
        }
      }
    }

    delete sBmp1.pBitmap;
    delete sBmp2.pBitmap;
    //::delete sBmp1.pBitmap;
    //::delete sBmp2.pBitmap;
    sBmp1.pIStream->Release();
    sBmp2.pIStream->Release();
    return float(same) / float(xMax*yMax);
  }

  float getSimilar(char* szFile1, char* szFile2)
  {
    int size1 = getFileSize(szFile1);
    int size2 = getFileSize(szFile2);
    if (size1 <= 0) return 0;
    if (size2 <= 0) return 0;
    char* szData1 = new char[size1];
    char* szData2 = new char[size2];
    std::ifstream f1;
    std::ifstream f2;
    f1.open(szFile1, std::ios::binary | std::ios::in);
    f2.open(szFile2, std::ios::binary | std::ios::in);
    if (f1.is_open())
    {
      f1.read(szData1, size1);
      f1.close();
    }
    if (f2.is_open())
    {
      f2.read(szData2, size2);
      f2.close();
    }
    float val = getSimilar2(szData1, size1, szData2, size2);
    if (szData1 != NULL) delete[] szData1;
    if (szData2 != NULL) delete[] szData2;
    return val;
  }
}