OpenCV2显示汉字，未使用CvxText和FreeType库

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。

• putText.h
• putText.cpp
• 演示

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文件putText.h

后面的cpp文件有一些简要说明。

#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

第二个函数putTextZH()，默认使用Arial字体，也可以设置成操作系统中已经安装的字体，如“宋体”、“微软雅黑”、“Times New Roman”等；默认显示非斜体、非下划线。

#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);}

演示

读取一个图片加入字体，显示。

#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;   }

加上字体显示效果如下：