Qt5图像放大缩小旋转及镜像

1、图像缩放

void ImgProcessor::ShowZoomIn()
{
    if(img.isNull())				//有效性判断
        return;
    QMatrix martix;					//声明一个QMatrix类的实例
    martix.scale(2,2);				//缩放比例
    img = img.transformed(martix);  //坐标转换
    //重新设置显示图形
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}

void ImgProcessor::ShowZoomOut()
{
    if(img.isNull())
        return;
    QMatrix matrix;
    matrix.scale(0.5,0.5);			//(a)
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}

2、图像旋转

void ImgProcessor::ShowRotate90()
{
    if(img.isNull())
        return;
    QMatrix matrix;
    matrix.rotate(90);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}

3、图像镜像

void ImgProcessor::ShowMirrorVertical()
{
    if(img.isNull())
        return;
    img=img.mirrored(false,true);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}

void ImgProcessor::ShowMirrorHorizontal()
{
    if(img.isNull())
        return;
    img=img.mirrored(true,false);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}