ubuntu下用Qt实现人脸识别之检测人脸并绘制人脸框（三）

要检测出人脸并且还要识别出这个人是谁，就得用到人脸算法，这个算法如果你足够牛X的话可以自己写出来，当然，如果像我一样是个小菜鸟的话就得领悟----万物为我所用，万物不为我所有----的真谛。那么，怎么做到呢？答案就是借助虹软人脸识别sdk。去虹软官网中将这个SDK下载下来，放到自己的工程目录下。
下载下来的SDK：

将头文件和库文件放到自己的工程目录下

然后在pro文件中将头文件和库文件包含添加进去即可。

最后在虹软官网中将自己账号中的APP_ID和SDK_KEY记下来，后续可以用来激活SDK

代码实现

基本思路：使用opencv来打开摄像头获取到数据，就这些数据传入到算法的接口中，得到人脸坐标，再使用paintEvent来绘制人脸框。

头文件代码如下（示例）：

#include <QWidget>
#include <QImage>
#include <QPainter>
#include <QObject>
#include <QTimer>

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/highgui.hpp"

#include "ASF/inc/merror.h"
#include "ASF/inc/asvloffscreen.h"
#include "ASF/inc/arcsoft_face_sdk.h"
#include "ASF/inc/amcomdef.h"

using namespace cv;

namespace Ui {
class hrQtPro;
}

class hrQtPro : public QWidget
{
    Q_OBJECT

public:
    explicit hrQtPro(QWidget *parent = 0);
    ~hrQtPro();

protected:
    void paintEvent(QPaintEvent* e);

private slots:
    int slotReadFarme();
    
private:
    Ui::hrQtPro *ui;
	VideoCapture capture;
	QTimer  *cvTimer;
	Mat cap;
	QImage qImg;
	ASF_MultiFaceInfo detectedFaces;
	MHandle handle;

    int ASFInit();
    int OpenCamera();
    QImage Mat2QImage(Mat &src);
};

cpp文件代码如下（示例）：

#include "hrqtpro.h"
#include "ui_hrqtpro.h"

hrQtPro::hrQtPro(QWidget *parent) :
    QWidget(parent),
    handle(NULL),
    ui(new Ui::hrQtPro)
{
	cvTimer = new QTimer(this);
	connect(cvTimer, SIGNAL(timeout()), this, SLOT(slotReadFarme()));
	ASFInit();
	OpenCamera();
}

hrQtPro::~hrQtPro()
{
	MRESULT res = ASFUninitEngine(handle);
	if (res != MOK)
	    printf("ASFUninitEngine fail: %d\n", res);
	else
	    printf("ASFUninitEngine sucess: %d\n", res);
    if(cvTimer) {
        cvTimer->stop();
        delete cvTimer;
        cvTimer = NULL;
    }
    delete ui;
}

int hrQtPro::ASFInit()
{
    MRESULT res = MOK;
#if 1
	//激活SDK，只需要激活一次即可
	//这里的APP_ID和SDK_KEY是从官网中获取到的
    res = ASFOnlineActivation("APP_ID", "SDK_KEY");
    if (MOK != res && MERR_ASF_ALREADY_ACTIVATED != res)
        qDebug("ASFOnlineActivation fail: %d\n", res);
    else
        qDebug("ASFOnlineActivation sucess: %d\n", res);
#endif
	//只是检测人脸，如果需要人脸识别还需要或上ASF_FACERECOGNITION，例如：ASF_FACE_DETECT | ASF_FACERECOGNITION
    MInt32 mask = ASF_FACE_DETECT;
    res = ASFInitEngine(ASF_DETECT_MODE_VIDEO, ASF_OP_0_ONLY, 16, 5, mask, &handle);
    if (res != MOK)
        qDebug("ASFInitEngine fail: %d\n", res);
    else
        qDebug("ASFInitEngine sucess: %d\n", res);
    return res;
}

int hrQtPro::OpenCamera()
{
	//打开摄像头
    if(capture.open(0)) { 
        qDebug() << "open success";
    } else {
        qDebug() << "open error";
        return -1;
    }
    //设置格式
    capture.set(cv::CAP_PROP_FOURCC, cv::VideoWriter::fourcc('M','J','P','G'));
    cvTimer->start(20);
    return 0;
}
//图像宽度需要四字节对齐，否则需要裁剪。
void CutIplImage(IplImage* src, IplImage* dst, int x, int y)
{
    CvSize size = cvSize(dst->width, dst->height);//区域大小
    cvSetImageROI(src, cvRect(x, y, size.width, size.height));//设置源图像ROI
    cvCopy(src, dst); //复制图像
    cvResetImageROI(src);//源图像用完后，清空ROI
}
//Mat转换为QImage
QImage hrQtPro::Mat2QImage(Mat &src) {
    if(src.type() == CV_8UC3) {
        const uchar *pSrc = (const uchar*)src.data;
        QImage qImage(pSrc,src.cols,src.rows,src.step,QImage::Format_RGB888);
        return qImage.rgbSwapped();
    }
    return QImage();
}

int hrQtPro::slotReadFarme()
{
	//读取摄像头数据
   capture.read(cap);
   if(!cap.data || cap.empty()) {
       return -1;
   }
   //Mat转换为QImage
   qImg = Mat2QImage(cap);
   if(qImg.isNull())
       return -1;

   IplImage ipi(cap);
   IplImage* img = cvCreateImage(cvSize(ipi.width - ipi.width % 4,
                                        ipi.height), IPL_DEPTH_8U, ipi.nChannels);
   ASVLOFFSCREEN offscreen = { 0 };
   if (img) {
       CutIplImage(&ipi, img, 0, 0);
       offscreen.u32PixelArrayFormat = ASVL_PAF_RGB24_B8G8R8;
       offscreen.i32Width = img->width;
       offscreen.i32Height = img->height;
       offscreen.pi32Pitch[0] = img->widthStep;
       offscreen.ppu8Plane[0] = (MUInt8*)img->imageData;

       MRESULT res = ASFDetectFacesEx(handle, &offscreen, &detectedFaces);
       if (MOK != res) {
           qDebug("ASFDetectFacesEx failed: %d\n", res);
       }
       cvReleaseImage(&img);
   }

}
//绘制人脸框
void hrQtPro::paintEvent(QPaintEvent* e)
{
    if(!qImg.isNull()) {
        QPainter painter(&qImg);
        if(detectedFaces.faceNum > 0) {
        	// 设置人脸框颜色
            painter.setPen(QColor(255, 0, 0));
            //绘制人脸的框
            painter.drawRect(detectedFaces.faceRect[0].left,
                    detectedFaces.faceRect[0].top,
                    detectedFaces.faceRect[0].right - detectedFaces.faceRect[0].left,
                    detectedFaces.faceRect[0].bottom - detectedFaces.faceRect[0].top);
        }
        ui->previewLabel->setPixmap(QPixmap::fromImage(qImg));
    }
}

最后结果

OK，完成。