目录
- 重要代码
- Demo演示
- 完整代码
废话：
有时候我们是从物品的斜上方拍摄的图片，看起来不直观，需要把视角拉正，这样的一个操作就叫做 梯度矫正，需要用到的技术是 Opencv 的透视变换。
这个只是一个简单的演示demo，如果完善一下，比如物品检测，可以应用更多的场景，比如常见的：文件、资料上传，软管摄像头的应用等，怎么编程客栈说也是一个技术点吧
重要代码
/**
* @brief hDLL_gradientAuto 梯度矫正
* @param src 输入图像
* @param dst 输出图像
* @param flag 方向,[0(左),1(上),2(右),3(下)]
* @param val 矫正度数,像素,[10 ~ 100]
* @return 0(成功)，-1(失败)
*/
int MainWindow::hDLL_gradientAuto(Mat &src, Mat &dst, int flag, int val)
{
if(flag != 0 && flag != 1 && flag != 2 && flag != 3) return -1;
if(val < 10 || val > 100) return -1;
int width = src.cols;
int height = src.rows;
Mat M;
// flag 方向,[0(左),1(上),2(右),3(下)]
switch (flag) {
case 0:
{
Point2f pts_src[] = { Point(val,val), Point(width, 0), Point(width, height), Point(val, height-val)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M = cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
case 1:
{
Point2f pts_src[] = { Point(val,val), Point(width-val, val), Point(width, height), Point(0, height)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M = cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
case 2:
{
Point2f pts_src[] = { Point(0,0), Point(width-val, val), Point(width-val, height-val), Point(0, height)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M = cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
case 3:
{
Point2f pts_src[] = { Point(0,0), Point(width, 0), Point(width-val, height-val), Point(val, height-val)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M =编程客栈 cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
}
cv::warpPerspective(src, dst, M, dst.size(), cv::INTER_LINEAR , cv::BORDER_REPLICATE);
return 0;
}
Demo演示
完整代码
.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QImage>
#include <QDebug>
#include <QtMath>
#include "opencv2/opencv.http://www.devze.comhpp"
using namespace cv;
QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
void updateQLabelImage();
Mat QImage2Mat(QImage &img);
QImage Mat2QImage(Mat &img);
/**
* @brief hDLL_gradientAuto 梯度矫正
* @param src 输入图像
* @param dst 输出图像
* @param flag 方向,[0(左),1(上),2(右),3(下)]
* @param val 矫正度数,像素,[10 ~ 100]
* @return 0(成功)，-1(失败)
*/
int hDLL_gradientAuto(Mat &src, Mat &dst, int flag, int val);
public slots:
void horChange(int index);
void verChange(int index);
private:
Ui::MainWindow *ui;
QImage m_img; // 原图
QImage m_img_dst; // 处理过的图像
};
#endif // MAINWINDOW_H
.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
connect(ui->horizontalSlider, SIGNAL(valueChanged(int)), this, SLOT(horChange(int)));
connect(ui->verticalSlider, SIGNAL(valueChanged(int)), this, SLOT(verChange(int)));
m_img = QImage("F:1.jpg");
m_img_dst = m_img;
updateQLabelImage();
}
MainWindow::~MainWindow()
{
delete ui;
}
// 更新QLabel里面的图像
void MainWindow::updateQLabelImage()
{
// m_img = m_img.scaled(ui->label->width(), ui->label->height());
QImage img_show = m_img_dst.scaled(ui->label->width(), ui->label->height());
ui->label->setPixmap(QPixmap::fromImage(img_show));
}
Mat MainWindow::QImage2Mat(QImage &img)
{
cv::Mat mat;
switch (img.format())
{
case QImage::Format_RGB32: //一般Qt读入彩色图后为此格式
mat = cv::Mat(img.height(), img.width(), CV_8UC4, (void*)img.constBits(), img.bytesperline());
cv::cvtColor(mat,mat,cv::COLOR_BGRA2BGR); //转3通道
break;
case QImage::Format_RGB888:
mat = cv::Mat(img.height(), img.width(), CV_8UC3, (void*)img.constBits(), img.bytesPerLine());
cv::cvtColor(mat,mat,cv::COLOR_RGB2BGR);
break;
case QImage::Format_Indexed8:
mat = cv::Mat(img.height(), img.width(), CV_8UC1, (void*)img.constBits(), img.bytesPerLine());
break;
}
return mat;
}
QImage MainWindow::Mat2QImage(Mat &img)
{
if(img.type()==CV_8UC1 || img.type()==CV_8U)
{
QImage image((const uchar *)img.data, img.cols, img.rows, img.step, QImage::Format_Grayscale8);
return image;
}
else if(img.type()==CV_8UC3)
{
QImage image((const uchar *)img.data, img.cols, img.rows, img.step, QImage::Format_RGB888);
return image.rgbSwapped(); //r与b调换
}
}
int MainWindow::hDLL_gradientAuto(Mat &src, Mat &dst, int flag, int val)
{
if(flag != 0 && flag != 1 && flag != 2 && flag != 3) return -1;
if(val < 10 || val > 100) return -1;
int width = src.cols;
int height = srcnPRDNrIIwy.rows;
Mat M;
// flag 方向,[0(左),1(上),2(右),3(下)]
switch (flag) {
case 0:
{
Point2f pts_src[] = { Point(val,val), Point(width, 0), Point(width, height), Point(val, height-val)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M = cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
case 1:
{
Point2f pts_src[] = { Point(val,val), Point(width-val, val), Point(width, height), Point(0, height)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M = cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
case 2:
{
Point2f pts_src[] = { Point(0,0), Point(width-val, val), Point(width-val, height-val), Point(0, height)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M = cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
case 3:
{
Point2f pts_src[] = { Point(0,0), Point(width, 0), Point(width-val, height-val), Point(val, height-val)};
Point2f pts_dst[] = { Point(0, 0), Point(width, 0), Point(width, height) ,Point(0, height) };
M = cv::getPerspectiveTransform(pts_src, pts_dst);
}break;
}
cv::warpPerspective(src, dst, M, dst.size(), cv::INTER_LINEAR , cv::BORDER_REPLICATE);
return 0;
}
// 横向改变
void MainWindow::horChange(int index)
{
qDebug() << "hor:" << index;
if(index == 0)
编程客栈 {
m_img_dst = m_img;
}
else if(index < 0)
{
int val = abs(index) * 10;
Mat src = QImage2Mat(m_img);
Mat dst;
hDLL_gradientAuto(src, dst, 0, val);
m_img_dst = Mat2QImage(dst);
}
else if (index > 0)
{
int val = abs(index) * 10;
Mat src = QImage2Mat(m_img);
Mat dst;
hDLL_gradientAuto(src, dst, 2, val);
m_img_dst = Mat2QImage(dst);
}
updateQLabelImage();
}
// 竖向改变
void MainWindow::verChange(int index)
{
qDebug() << "ver:" << index;
if(index == 0)
{
m_img_dst = m_img;
}
else if(index < 0)
{
int val = abs(index) * 10;
Mat src = QImage2Mat(m_img);
Mat dst;
hDLL_gradientAuto(src, dst, 3, val);
m_img_dst = Mat2QImage(dst);
}
else if (index > 0)
{
int val = abs(index) * 10;
Mat src = QImage2Mat(m_img);
Mat dst;
hDLL_gradientAuto(src, dst, 1, val);
m_img_dst = Mat2QImage(dst);
}
updateQLabelImage();
}
环境是：Qt 5.15.2 + Opencv V4.8.0，如果需要下载代码，自己调试，自己配置环境即可
代码仓库：https://gitee.com/vvvj/qt-test-gradient-auto
以上就是Qt+Opencv实现梯度矫正功能的详细内容，更多关于Qt Opencv梯度矫正的资料请关注编程客栈(www.devze.com)其它相关文章！
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