opencv学习笔记-图片显示中文

运行环境：

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vs2013、opencv3.3、win10-64bit

下载显示中文类：

OpenCV默认是不支持显示中文字符的，于是网上有人自己写了一个类实现，只需要下载到自己的代码文件中，添加头文件就可以通过调用函数来显示中文了。

1）显示中文类下载链接：（若链接失效，文字最后有源码）

     百度网盘：https://pan.baidu.com/s/1gdYatLLOKmDI-_6OOzdQNg 
     提取码：o7p7 

2）下载后文件名为：“puttextzh.cpp”，“puttextzh.cpp”

3）将这两个文件加入到项目文件夹中，并加入工程中

4）使用时加入头文件“puttextzh.h”

函数原型：

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void putTextZH(
               cv::Mat &dst, 
               const char* str, 
               cv::Point org, 
               cv::Scalar color, 
               int fontSize, 
               const char* fn, 
               bool italic, 
               bool underline
               )

参数解释：

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dst：输入，原图像，即待加中文的图像；

str：中文字符串；

org：字符串像素点位置：

color：字符串颜色；

fontSize：字体大小；

fn：字体类型（默认Arial字体类型）：

italic：斜体（默认无斜体）：

underline：下划线（默认无下划线）：

示例代码：

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在lenna图像坐标为(50,60)位置加上字符串“我的名字叫lenna”，字体颜色：白色，字体大小：40，字体类型：微软雅黑

putTextZH(srcImg, "我的名字叫lenna", Point(50, 60), Scalar(255, 255, 255), 40, "微软雅黑");

#include
#include"opencv2/opencv.hpp"
#include"opencv2/highgui/highgui.hpp"
#include"puttextzh.h"

using namespace std;
using namespace cv;

int main()
{
	Mat srcImg = imread("E:\\Project\\opencvPicture\\lenna.jpg");//打开图像
	if (srcImg.empty())//判断是否正确打开图片
	{
		cout << "加载图像失败！" << endl;
		return -1;
	}
	imshow("原图", srcImg);//显示原图

	putTextZH(srcImg, "我的名字叫lenna", Point(50, 60), Scalar(255, 255, 255), 40, "微软雅黑");//图像上加中文
	imshow("原图加中文", srcImg);

	waitKey(0);
	return 0;
}

运行结果：

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中文类库源码：

puttextzh.cpp

#include "puttextzh.h"
#include "windows.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(cv::Mat &dst, const char* str, cv::Point org, cv::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);
}

puttextzh.h

#ifndef PUTTEXTZH_H_
#define PUTTEXTZH_H_
//#include "opencv.hpp"
#include "opencv2/opencv.hpp"

void putTextZH(cv::Mat &dst, const char* str, cv::Point org, cv::Scalar color, int fontSize,
    const char *fn = "Arial", bool italic = false, bool underline = false);

#endif // PUTTEXT_H_

参考：https://blog.csdn.net/mars_xiaolei/article/details/91381148