zbar 二维码译码算法获取译码后的二维码位置并在QT画出轮廓

1.获取二维码位置坐标，四个点：
int main(void) {
    Mat mat = imread("E:\\qrcodetest.jpg");
    zbar::ImageScanner scnner;
    scnner.set_config(zbar::ZBAR_NONE, zbar::ZBAR_CFG_ENABLE, 1);
    cvtColor(mat, mat, COLOR_BGR2GRAY);
    zbar::Image imageZbar(mat.cols, mat.rows, "Y800", (uchar *)mat.data, mat.cols * mat.rows);
    scnner.scan(imageZbar);
    SymbolIterator symbol = imageZbar.symbol_begin();
    if (imageZbar.symbol_begin() != imageZbar.symbol_end()) {
        //图中有二维码
        SymbolIterator iter = imageZbar.symbol_begin();
        //iter->get_location_size(): 二维码矩形有几个点,一般都是4个,也就是二维码一般都是方形的
        cout << iter->get_location_size() << endl;
        for (int i = 0; i < iter->get_location_size();i ++) {
            //获取第i个点的x
            cout << iter->get_location_x(i) << endl;
            //获取第i个点的y
            cout << iter->get_location_y(i) << endl;
        }
    }

    getc(stdin);
    return 0;
}

2. QT 画轮廓线：

static const QPointF points[4] = {QPointF(30, 40), QPointF(60, 150), QPointF(150, 160), QPointF(220, 100)};

painter.drawPolygon(points, 4);

#include <QWidget>
#include <QPainter>
#include <QPolygon>
 
class PolygonWidget : public QWidget {
protected:
    void paintEvent(QPaintEvent *event) override {
        QPainter painter(this);
        painter.setBrush(Qt::blue); // 设置填充颜色为蓝色
        painter.setPen(Qt::NoPen); // 不绘制边框
 
        QPolygon polygon;
        polygon << QPoint(10, 10) << QPoint(100, 10) << QPoint(50, 90); // 定义多边形的顶点
        painter.drawPolygon(polygon); // 绘制多边形
    }
};