Qt 从图片中截取到需要的部分

[努力的草根]

我在qgraphicsView放了一张图片，然后我想通过鼠标这张图片上画一个形状然后将这个形状里面的图片保存下来

[彩阳]

QPixmap QPixmap::copy(int x, int y, int width, int height) const
QImage QImage::copy(int x, int y, int width, int height) const

随你所用。

[fyn272064949]

void Widget::mousePressEvent(QMouseEvent *e) { m_Path = QPainterPath(e->pos()); isEnd = false; } void Widget::mouseMoveEvent(QMouseEvent *e) { m_Path.lineTo(e->pos()); update(); } void Widget::mouseReleaseEvent(QMouseEvent *e) { m_Path.closeSubpath(); update(); isEnd = true; } void Widget::paintEvent(QPaintEvent *) { QPainter p(this); QImage temp("a.jpg"); p.drawImage(this->rect(), temp, temp.rect()); p.drawPath(m_Path); if(isEnd) { QPainterPath tempPath = m_Path; tempPath.translate(-tempPath.boundingRect().topLeft()); QImage img(m_Path.boundingRect().size().toSize(), QImage::Format_ARGB32); QPainter imgPainter(&img); imgPainter.setBackgroundMode(Qt::TransparentMode); QImage temp2 = temp.scaled(this->size()); temp2 = temp2.copy(m_Path.boundingRect().toRect()); imgPainter.fillPath(tempPath, QBrush(temp2)); img.save("temp.png"); isEnd = false; } } 我为何这么吊？？？？ 代码没有优化， 自己去优化吧

[看到吃的就开心]

void MainWindow::caculate()
{
static int iCount = 1;
while(!_bStopped)
{
cv::Mat frame;
cv::Mat frameCalibration;

_videoCapture.read(frame);
if(_bCut)
{
_bCut = false;
cv::imwrite((QCoreApplication::applicationDirPath()+"/../pictures/"+QString::number(iCount)+".jpg").toStdString(), frame);
iCount++;
}
if(iCount > 20)
{
_timer->stop();
cv::destroyAllWindows();
return;
}
int64 start = QDateTime::currentMSecsSinceEpoch();
cv::remap(frame, frameCalibration, map1, map2, cv::INTER_LINEAR);
int64 end = QDateTime::currentMSecsSinceEpoch();
qDebug()<<start <<end <<end-start;

// cv::imshow("cut", frameCalibration);
cv::imshow("cut", frame);
cv::waitKey(1);
}
}

void MainWindow::on_pushButton_clicked()
{
//_bStopped = !_bStopped;
_bCut = true;
}