采用windows的GDI显示系统的TrueType字体，没有封装，就两个函数，分成了h和cpp文件，可以自己编辑文件名和函数名，亦可以直接将cpp的代码复制到你需要的程序中。FReeType打包的win32的静态库是可以在C#通过dll引用进行调用，这需要其版本跟CvxText对应，否则会出现错误，其在x64平台也一样。

• putText.h

• #ifndef PUTTEXT_H_
  #define PUTTEXT_H_
  
  #include <windows.h>
  #include <string>
  #include <opencv2/opencv.hpp>
  
  using namespace cv;
  
  void GetStringSize(HDC hDC, const char* str, int* w, int* h);
  void putTextZH(Mat &dst, const char* str, Point org, Scalar color, int fontSize,
      const char *fn = "Arial", bool italic = false, bool underline = false);
  
  #endif // PUTTEXT_H_

  
  
  

• putText.cpp

• #include "putText.h"
  
  void GetStringSize(HDC hDC, const char* str, int* w, int* h)
  {
      SIZE size;
      GetTextExtentPoint32A(hDC, str, strlen(str), &size);
      if (w != 0) *w = size.cx;
      if (h != 0) *h = size.cy;
  }
  
  void putTextZH(Mat &dst, const char* str, Point org, Scalar color, int fontSize, const char* fn, bool italic, bool underline)
  {
      CV_Assert(dst.data != 0 && (dst.channels() == 1 || dst.channels() == 3));
  
      int x, y, r, b;
      if (org.x > dst.cols || org.y > dst.rows) return;
      x = org.x < 0 ? -org.x : 0;
      y = org.y < 0 ? -org.y : 0;
  
      LOGFONTA lf;
      lf.lfHeight = -fontSize;
      lf.lfWidth = 0;
      lf.lfEscapement = 0;
      lf.lfOrientation = 0;
      lf.lfWeight = 5;
      lf.lfItalic = italic;   //斜体
      lf.lfUnderline = underline; //下划线
      lf.lfStrikeOut = 0;
      lf.lfCharSet = DEFAULT_CHARSET;
      lf.lfOutPrecision = 0;
      lf.lfClipPrecision = 0;
      lf.lfQuality = PROOF_QUALITY;
      lf.lfPitchAndFamily = 0;
      strcpy_s(lf.lfFaceName, fn);
  
      HFONT hf = CreateFontIndirectA(&lf);
      HDC hDC = CreateCompatibleDC(0);
      HFONT hOldFont = (HFONT)SelectObject(hDC, hf);
  
      int strBaseW = 0, strBaseH = 0;
      int singleRow = 0;
      char buf[1 << 12];
      strcpy_s(buf, str);
      char *bufT[1 << 12];  // 这个用于分隔字符串后剩余的字符，可能会超出。
      //处理多行
      {
          int nnh = 0;
          int cw, ch;
  
          const char* ln = strtok_s(buf, "\n",bufT);
          while (ln != 0)
          {
              GetStringSize(hDC, ln, &cw, &ch);
              strBaseW = max(strBaseW, cw);
              strBaseH = max(strBaseH, ch);
  
              ln = strtok_s(0, "\n",bufT);
              nnh++;
          }
          singleRow = strBaseH;
          strBaseH *= nnh;
      }
  
      if (org.x + strBaseW < 0 || org.y + strBaseH < 0)
      {
          SelectObject(hDC, hOldFont);
          DeleteObject(hf);
          DeleteObject(hDC);
          return;
      }
  
      r = org.x + strBaseW > dst.cols ? dst.cols - org.x - 1 : strBaseW - 1;
      b = org.y + strBaseH > dst.rows ? dst.rows - org.y - 1 : strBaseH - 1;
      org.x = org.x < 0 ? 0 : org.x;
      org.y = org.y < 0 ? 0 : org.y;
  
      BITMAPINFO bmp = { 0 };
      BITMAPINFOHEADER& bih = bmp.bmiHeader;
      int strDrawLineStep = strBaseW * 3 % 4 == 0 ? strBaseW * 3 : (strBaseW * 3 + 4 - ((strBaseW * 3) % 4));
  
      bih.biSize = sizeof(BITMAPINFOHEADER);
      bih.biWidth = strBaseW;
      bih.biHeight = strBaseH;
      bih.biPlanes = 1;
      bih.biBitCount = 24;
      bih.biCompression = BI_RGB;
      bih.biSizeImage = strBaseH * strDrawLineStep;
      bih.biClrUsed = 0;
      bih.biClrImportant = 0;
  
      void* pDibData = 0;
      HBITMAP hBmp = CreateDIBSection(hDC, &bmp, DIB_RGB_COLORS, &pDibData, 0, 0);
  
      CV_Assert(pDibData != 0);
      HBITMAP hOldBmp = (HBITMAP)SelectObject(hDC, hBmp);
  
      //color.val[2], color.val[1], color.val[0]
      SetTextColor(hDC, RGB(255, 255, 255));
      SetBkColor(hDC, 0);
      //SetStretchBltMode(hDC, COLORONCOLOR);
  
      strcpy_s(buf, str);
      const char* ln = strtok_s(buf, "\n",bufT);
      int outTextY = 0;
      while (ln != 0)
      {
          TextOutA(hDC, 0, outTextY, ln, strlen(ln));
          outTextY += singleRow;
          ln = strtok_s(0, "\n",bufT);
      }
      uchar* dstData = (uchar*)dst.data;
      int dstStep = dst.step / sizeof(dstData[0]);
      unsigned char* pImg = (unsigned char*)dst.data + org.x * dst.channels() + org.y * dstStep;
      unsigned char* pStr = (unsigned char*)pDibData + x * 3;
      for (int tty = y; tty <= b; ++tty)
      {
          unsigned char* subImg = pImg + (tty - y) * dstStep;
          unsigned char* subStr = pStr + (strBaseH - tty - 1) * strDrawLineStep;
          for (int ttx = x; ttx <= r; ++ttx)
          {
              for (int n = 0; n < dst.channels(); ++n){
                  double vtxt = subStr[n] / 255.0;
                  int cvv = vtxt * color.val[n] + (1 - vtxt) * subImg[n];
                  subImg[n] = cvv > 255 ? 255 : (cvv < 0 ? 0 : cvv);
              }
  
              subStr += 3;
              subImg += dst.channels();
          }
      }
  
      SelectObject(hDC, hOldBmp);
      SelectObject(hDC, hOldFont);
      DeleteObject(hf);
      DeleteObject(hBmp);
      DeleteDC(hDC);
  }

  
  main

• #include "opencv2/opencv.hpp"
  
  #include "putText.h"
  
  using namespace std;
  using namespace cv;
  
  int main()
  {
      Mat img = imread("src.jpg");
  
      putTextZH(img, "Arial字体换...\n行显示!", Point(50, 50), Scalar(0, 0, 255), 30, "Arial");
      putTextZH(img, "微软雅黑字体换...\n行，斜体，下划线，显示!", Point(50, 100), Scalar(0, 255, 0), 30, "微软雅黑", true, true);
      putTextZH(img, "楷体字体换...\n行，斜体，下划线，显示!", Point(50, 200), Scalar(128, 255, 0), 30, "楷体", true, true);
  
      imshow("test", img);
  
      waitKey();
  
      return 0;   
  }

  
  报错：fatal error C1010: 在查找预编译头时遇到意外的文件结尾。是否忘记了向源中添加“#include "stdafx.h"