opencv学习_qt显示图片
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opencv+qt
1.opencv显示图片
hpp
三个主要函数
- imgInit():负责加载图片,转换格式等操作
- imgProc():负责对图片的处理和算法实现
- imgShow():负责在窗口显示图片
#include "opencv2/opencv.hpp"
using namespace cv;
class MainWindow : public QMainWindow
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
void imgInit();
void imgProc(float contrast,int brightness);
void imgShow();
private slots:
void on_pushButton_clicked();
private:
Ui::MainWindow *ui;
Mat myImg;
QImage myQImg;
;
cpp
void MainWindow::imgInit()
Mat ImgData = imread("test.jpg");
cvtColor(ImgData,myImg,COLOR_BGR2RGB);
myQImg = QImage((const unsigned char*)(myImg.data),myImg.cols,myImg.rows,QImage::Format_RGB888);
imgShow();
void MainWindow::imgProc(float con, int bri)
Mat src = myImg;
Mat dst = Mat::zeros(src.size(),src.type());
src.convertTo(dst,-1,con,bri);
myQImg = QImage((const unsigned char*)(dst.data),dst.cols,dst.rows,QImage::Format_RGB888);
imgShow();
void MainWindow::imgShow()
ui->label->setPixmap(QPixmap::fromImage(myQImg.scaled(ui->label->size())));//显示到Qlabel上
void MainWindow::on_pushButton_clicked()
imgInit();
注意:
Mat默认的是BGR空间,而QImage是RGB,所以使用cvtColor
函数预处理一下。
第二个函数QImage(uchar *data, int width, int height, QImage::Format format)
2.添加滑条处理图片
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
ui->setupUi(this);
imgInit();
imgShow();
ui->verticalSlider->setSliderPosition(50);
ui->verticalSlider_2->setSliderPosition(50);
void MainWindow::on_verticalSlider_sliderMoved(int position)
imgProc(position/33.3, 0);
void MainWindow::on_verticalSlider_valueChanged(int value)
imgProc(value/33.3, 0);
void MainWindow::on_verticalSlider_2_sliderMoved(int position)
imgProc(1.0, position);
void MainWindow::on_verticalSlider_2_valueChanged(int value)
imgProc(1.0, value);
3.滤波函数
四个滤波函数:
cv::blur()
:均值滤波cv::cv::GaussianBlur()
:高斯滤波cv::medianBlur()
:中值滤波cv::bilateralFilter()
:双边滤波
void MainWindow::imgInit()
QString imgPath = "test.jpg";
Mat imgData = imread(imgPath.toLatin1().data());
if(imgData.empty())qDebug("no img");return;
cvtColor(imgData,imgData,COLOR_BGR2RGB);
myImg = imgData;
myBlurQImg = QImage((const unsigned char*)(imgData.data),imgData.cols,imgData.rows,QImage::Format_RGB888);
myGaussianQImg = myBlurQImg;
myMedianQImg = myBlurQImg;
myBilateralQImg = myBlurQImg;
imgShow();
void MainWindow::imgShow()
ui->labAverage->setPixmap(QPixmap::fromImage(myBlurQImg.scaled(ui->labAverage->size())));
ui->labGaussian->setPixmap(QPixmap::fromImage(myGaussianQImg.scaled(ui->labGaussian->size())));
ui->labMedian->setPixmap(QPixmap::fromImage(myMedianQImg.scaled(ui->labMedian->size())));
ui->labBilateral->setPixmap(QPixmap::fromImage(myBilateralQImg.scaled(ui->labBilateral->size())));
void MainWindow::imgProc(int kernel)
Mat src = myImg;
Mat dst1 = src.clone();
for (int i=1 ; i<kernel ; i=i+2 ) cv::blur(src,dst1,Size(i,i),Point(-1,-1));
myBlurQImg = QImage((const unsigned char*)(dst1.data),dst1.cols,dst1.rows,QImage::Format_RGB888);
Mat dst2 = src.clone();
for (int i=1 ; i<kernel ; i=i+2 ) cv::GaussianBlur(src,dst2,Size(i,i),0,0);
myGaussianQImg = QImage((const unsigned char*)(dst2.data),dst2.cols,dst2.rows,QImage::Format_RGB888);
Mat dst3 = src.clone();
for (int i=1 ; i<kernel ; i=i+2 ) cv::medianBlur(src,dst3,i);
myMedianQImg = QImage((const unsigned char*)(dst3.data),dst3.cols,dst3.rows,QImage::Format_RGB888);
Mat dst4 = src.clone();
for (int i=1 ; i<kernel ; i=i+2 ) cv::bilateralFilter(src,dst4,i,i*2,i/2);
myBilateralQImg = QImage((const unsigned char*)(dst4.data),dst4.cols,dst4.rows,QImage::Format_RGB888);
imgShow();
void MainWindow::on_verticalSlider_sliderMoved(int position)
imgProc(position);
void MainWindow::on_verticalSlider_valueChanged(int value)
imgProc(value);
void MainWindow::on_btnsave_clicked()
QString savefile = QFileDialog::getSaveFileName(this,tr("save file"),QDir::currentPath(),tr("pic(*.jpg *.png *.jpeg *.bmp)"));
if(savefile.isEmpty())return;
QScreen *screen = QGuiApplication::primaryScreen();
if(ui->rbaverage->isChecked()) screen->grabWindow(ui->labAverage->winId()).save(savefile);
if(ui->rbgaussian->isChecked()) screen->grabWindow(ui->labGaussian->winId()).save(savefile);
if(ui->rbmedian->isChecked()) screen->grabWindow(ui->labMedian->winId()).save(savefile);
if(ui->rbbilateral->isChecked()) screen->grabWindow(ui->labBilateral->winId()).save(savefile);
4.混合图像
混合图像函数:
cv::addWeighted(原图2,alpha,原图1,1-alpha,gramma,合成图);
:alpha在0~1之间
void MainWindow::imgInit()
Mat imgData = imread("test01.jpg");
cvtColor(imgData,imgData,COLOR_BGR2RGB);
myImg = imgData;
myQImg = QImage((const uchar*)(myImg.data),myImg.cols,myImg.rows,QImage::Format_RGB888);
imgShow();
void MainWindow::imgProc(float alpha)
Mat src1 = myImg;
Mat src2 = imread("test02.jpg");
cvtColor(src2,src2,COLOR_BGR2RGB);
//Warning 因为我们对 src1 和 src2 求 和 ,它们必须要有相同的尺寸(宽度和高度)和类型。
cv::resize(src2,src2,Size(src1.cols,src1.rows));
Mat dst;
cv::addWeighted(src2,alpha,src1,1-alpha,0,dst); //g(i,j)=alpha*f0(i,j)+(1-alpha)*f1(i,j)
myQImg = QImage((const uchar*)(dst.data),dst.cols,dst.rows,QImage::Format_RGB888);
imgShow();
void MainWindow::imgShow()
ui->label->setPixmap(QPixmap::fromImage(myQImg.scaled(ui->label->size())));
void MainWindow::on_verticalSlider_sliderMoved(int position)
imgProc(position/100.0);
void MainWindow::on_verticalSlider_valueChanged(int value)
imgProc(value/100.0);
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