图像处理---《在图片上打印文字 windows+GDI+TrueType字体》

图像处理---《在图片上打印文字  windows+GDI+TrueType字体》

　　刚开始使用的是putText()函数做，缺陷是只能显示非中文； 接着，看大多数推荐Freetype库来做，尝试了，可以的，适合图像输入的是IPLImage格式，其他格式需要转换一下；现在，看到可以不使用Freetype库做的，也尝试了，好用：

上接前几篇，（3）“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。”

　　

//====================================================================
//
// 文件: textTrueType.h
//
// 说明: OpenCV汉字输出
//
//====================================================================

#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_

//====================================================================
//
// 文件: textTrueType.cpp
//
// 说明: OpenCV汉字输出
//
//====================================================================

//#include "putText.h"
#include "textTrueType.h"

void GetStringSize(HDC hDC, const char* str, int* w, int* h)
{
    SIZE size;
    GetTextExtentPoint32A(hDC, str, strlen(str), &size);
    if (w != ) *w = size.cx;
    if (h != ) *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 !=  && (dst.channels() ==  || dst.channels() == ));

    int x, y, r, b;
    if (org.x > dst.cols || org.y > dst.rows) return;
    x = org.x <  ? -org.x : ;
    y = org.y <  ? -org.y : ;

    LOGFONTA lf;
    lf.lfHeight = -fontSize;
    lf.lfWidth = ;
    lf.lfEscapement = ;
    lf.lfOrientation = ;
    lf.lfWeight = ;
    lf.lfItalic = italic;   //斜体
    lf.lfUnderline = underline; //下划线
    lf.lfStrikeOut = ;
    lf.lfCharSet = DEFAULT_CHARSET;
    lf.lfOutPrecision = ;
    lf.lfClipPrecision = ;
    lf.lfQuality = PROOF_QUALITY;
    lf.lfPitchAndFamily = ;
    strcpy_s(lf.lfFaceName, fn);

    HFONT hf = CreateFontIndirectA(&lf);
    HDC hDC = CreateCompatibleDC();
    HFONT hOldFont = (HFONT)SelectObject(hDC, hf);

    int strBaseW = , strBaseH = ;
    int singleRow = ;
    char buf[ << ];
    strcpy_s(buf, str);
    char *bufT[ << ];  // 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 = ;
        int cw, ch;

        const char* ln = strtok_s(buf, "\n",bufT);
        while (ln != )
        {
            GetStringSize(hDC, ln, &cw, &ch);
            strBaseW = max(strBaseW, cw);
            strBaseH = max(strBaseH, ch);

            ln = strtok_s(, "\n",bufT);
            nnh++;
        }
        singleRow = strBaseH;
        strBaseH *= nnh;
    }

    if (org.x + strBaseW <  || org.y + strBaseH < )
    {
        SelectObject(hDC, hOldFont);
        DeleteObject(hf);
        DeleteObject(hDC);
        return;
    }

    r = org.x + strBaseW > dst.cols ? dst.cols - org.x -  : strBaseW - ;
    b = org.y + strBaseH > dst.rows ? dst.rows - org.y -  : strBaseH - ;
    org.x = org.x <  ?  : org.x;
    org.y = org.y <  ?  : org.y;

    BITMAPINFO bmp = {  };
    BITMAPINFOHEADER& bih = bmp.bmiHeader;
    int strDrawLineStep = strBaseW *  %  ==  ? strBaseW *  : (strBaseW *  +  - ((strBaseW * ) % ));

    bih.biSize = sizeof(BITMAPINFOHEADER);
    bih.biWidth = strBaseW;
    bih.biHeight = strBaseH;
    bih.biPlanes = ;
    bih.biBitCount = ;
    bih.biCompression = BI_RGB;
    bih.biSizeImage = strBaseH * strDrawLineStep;
    bih.biClrUsed = ;
    bih.biClrImportant = ;

    void* pDibData = ;
    HBITMAP hBmp = CreateDIBSection(hDC, &bmp, DIB_RGB_COLORS, &pDibData, , );

    CV_Assert(pDibData != );
    HBITMAP hOldBmp = (HBITMAP)SelectObject(hDC, hBmp);

    //color.val[2], color.val[1], color.val[0]
    SetTextColor(hDC, RGB(, , ));
    SetBkColor(hDC, );
    //SetStretchBltMode(hDC, COLORONCOLOR);

    strcpy_s(buf, str);
    const char* ln = strtok_s(buf, "\n",bufT);
    int outTextY = ;
    while (ln != )
    {
        TextOutA(hDC, , outTextY, ln, strlen(ln));
        outTextY += singleRow;
        ln = strtok_s(, "\n",bufT);
    }
    uchar* dstData = (uchar*)dst.data;
    int dstStep = dst.step / sizeof(dstData[]);
    unsigned char* pImg = (unsigned char*)dst.data + org.x * dst.channels() + org.y * dstStep;
    unsigned char* pStr = (unsigned char*)pDibData + x * ;
    for (int tty = y; tty <= b; ++tty)
    {
        unsigned char* subImg = pImg + (tty - y) * dstStep;
        unsigned char* subStr = pStr + (strBaseH - tty - ) * strDrawLineStep;
        for (int ttx = x; ttx <= r; ++ttx)
        {
            for (int n = ; n < dst.channels(); ++n){
                double vtxt = subStr[n] / 255.0;
                int cvv = vtxt * color.val[n] + ( - vtxt) * subImg[n];
                subImg[n] = cvv >  ?  : (cvv <  ?  : cvv);
            }

            subStr += ;
            subImg += dst.channels();
        }
    }

    SelectObject(hDC, hOldBmp);
    SelectObject(hDC, hOldFont);
    DeleteObject(hf);
    DeleteObject(hBmp);
    DeleteDC(hDC);
}

//====================================================================
//
// 文件: test_main.cpp
//
// 说明: OpenCV汉字输出，测试主函数
//
//====================================================================
#include "opencv2/opencv.hpp"

//#include "putText.h"
#include "textTrueType.h"

using namespace std;
using namespace cv;

/*int main()
{
    Mat img = imread("D:\\005_test_4\\testImg\\road_6.png");

    putTextZH(img, "Arial字体换...\n行显示!", Point(50, 50), Scalar(0, 0, 255), 30, "Arial");
    putTextZH(img, "Times New Roman字体换...\n行显示!", Point(50, 50), Scalar(0, 0, 255), 30, "Times New Roman");
    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;
}*/

void main()
{
    //Mat img(150,600,CV_8UC3,Scalar(255,255,255));//初始化图像
    Mat img = imread("D:\\005_test_4\\testImg\\road_6.png");
    putTextZH(img, "打印汉字，汉字，汉字！", Point(, ), Scalar(, , ), , "华文行楷");
    imwrite("1.png", img);
    imshow("", img);
    waitKey();
}

致谢：https://blog.csdn.net/wanggao_1990/article/details/52955056；https://blog.csdn.net/weixinhum/article/details/84074594；