摘要：
该原理基于Qt的OpenCV开发。以Qt为接口，OpenCV执行图像处理。
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原博主博客地址：https://blog.csdn.net/qq21497936
原博主博客导航：https://blog.csdn.net/qq21497936/article/details/102478062
本文章博客地址：https://blog.csdn.net/qq21497936/article/details/107090002
红胖子(红模仿)的博文大全：开发技术集合（包含Qt实用技术、树莓派、三维、OpenCV、OpenGL、ffmpeg、OSG、单片机、软硬结合等等）持续更新中…（点击传送门）
做算法过程中，需要一个平台来实时查看效果，记录处理过程，可以一键查看效果；
OpenCV的各种算法在Qt效果调试；
持续升级版本，敬请期待…
基于Qt的OpenCV开发，依托Qt作为界面，OpenCV进行图像处理。
《OpenCV开发笔记（三十四）：红胖子带你傻瓜式编译Qt+openCV3.4.1+opencv_contrib（全网最浅显易懂）》
《OpenCV开发笔记（四）：OpenCV图片和视频数据的读取与存储》
《OpenCV开发笔记（十三）：OpenCV图像对比度、亮度的调整》
《OpenCV开发笔记（十四）：算法基础之线性滤波-方框滤波》
《OpenCV开发笔记（十五）：算法基础之线性滤波-均值滤波》
《OpenCV开发笔记（十六）：算法基础之线性滤波-高斯滤波》
《OpenCV开发笔记（十八）：算法基础之非线性滤波-中值滤波》
《OpenCV开发笔记（十九）：算法基础之非线性滤波-双边滤波》
《OpenCV开发笔记（二十一）：算法基础之形态学滤波-膨胀》
《OpenCV开发笔记（二十二）：算法基础之形态学滤波-腐蚀》
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#ifndef COMMON_H
#define COMMON_H
#include <QImage>
#include <QDebug>
#include <QFileDialog>
#include <QColorDialog>
#include <QMessageBox>
#include <QHash>
// opencv
#include "opencv/highgui.h"
#include "opencv/cxcore.h"
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/opencv.hpp"
#include "opencv2/xphoto.hpp"
// opencv_contrib
#include <opencv2/xphoto.hpp>
#include <opencv2/ximgproc.hpp>
#include <opencv2/calib3d.hpp>
cv::Mat image2Mat(QImage image); // Qimage 转 cv::Mat
QImage mat2Image(cv::Mat mat); // cv::Mat 转 QImage
#endif // COMMON_H
#include "common.h"
cv::Mat image2Mat(QImage image)
{
cv::Mat mat;
switch(image.format())
{
case QImage::Format_ARGB32:
case QImage::Format_RGB32:
case QImage::Format_ARGB32_Premultiplied:
mat = cv::Mat(image.height(), image.width(), CV_8UC4, (void*)image.constBits(), image.bytesPerLine());
cv::cvtColor(mat, mat, CV_BGRA2BGR);
break;
case QImage::Format_RGB888:
mat = cv::Mat(image.height(), image.width(), CV_8UC3, (void*)image.constBits(), image.bytesPerLine());
cv::cvtColor(mat, mat, CV_BGR2RGB);
break;
case QImage::Format_Indexed8:
mat = cv::Mat(image.height(), image.width(), CV_8UC1, (void*)image.constBits(), image.bytesPerLine());
break;
}
return mat;
}
QImage mat2Image(cv::Mat mat)
{
if(mat.type() == CV_8UC1)
{
QImage image(mat.cols, mat.rows, QImage::Format_Indexed8);
// Set the color table (used to translate colour indexes to qRgb values)
image.setColorCount(256);
for(int i = 0; i < 256; i++)
{
image.setColor(i, qRgb(i, i, i));
}
// Copy input Mat
uchar *pSrc = mat.data;
for(int row = 0; row < mat.rows; row ++)
{
uchar *pDest = image.scanLine(row);
memcpy(pDest, pSrc, mat.cols);
pSrc += mat.step;
}
return image;
}
else if(mat.type() == CV_8UC3)
{
const uchar *pSrc = (const uchar*)mat.data;
QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_RGB888);
return image.rgbSwapped();
}
else if(mat.type() == CV_8UC4)
{
const uchar *pSrc = (const uchar*)mat.data;
QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_ARGB32);
return image.copy();
}
else
{
return QImage();
}
}
#ifndef DEMOCONTRASTANDBRIGHTNESSWIDGET_H
#define DEMOCONTRASTANDBRIGHTNESSWIDGET_H
#include <QWidget>
#include "common.h"
namespace Ui {
class DemoContrastAndBrightnessWidget;
}
class DemoContrastAndBrightnessWidget : public QWidget
{
Q_OBJECT
public:
explicit DemoContrastAndBrightnessWidget(QWidget *parent = 0);
~DemoContrastAndBrightnessWidget();
public:
void setFilePath(QString filePath);
protected:
void updateInfo();
void updateImage();
private slots:
void on_pushButton_openFile_clicked();
void on_horizontalSlider_beta_sliderMoved(int position);
void on_horizontalSlider_alpha_sliderMoved(int position);
void on_pushButton_broswer_clicked();
void on_spinBox_beta_valueChanged(int arg1);
void on_doubleSpinBox_alpha_valueChanged(double arg1);
void on_pushButton_showFile_clicked();
void on_pushButton_backgroundColor_clicked();
private:
Ui::DemoContrastAndBrightnessWidget *ui;
private:
QString _filePath;
cv::Mat _srcMat;
QImage _srcImage;
cv::Mat _dstMat;
QImage _dstImage;
};
#endif // DEMOCONTRASTANDBRIGHTNESSWIDGET_H
#include "DemoContrastAndBrightnessWidget.h"
#include "ui_DemoContrastAndBrightnessWidget.h"
DemoContrastAndBrightnessWidget::DemoContrastAndBrightnessWidget(QWidget *parent) :
QWidget(parent),
ui(new Ui::DemoContrastAndBrightnessWidget)
{
ui->setupUi(this);
}
DemoContrastAndBrightnessWidget::~DemoContrastAndBrightnessWidget()
{
delete ui;
}
void DemoContrastAndBrightnessWidget::setFilePath(QString filePath)
{
_filePath = filePath;
ui->lineEdit_filePath->setText(_filePath);
}
void DemoContrastAndBrightnessWidget::updateInfo()
{
if(_srcMat.data == 0)
{
return;
}
// mat行列与图片高度是对角线反向的
ui->label_size->setText(QString("%1 x %2").arg(_srcMat.rows).arg(_srcMat.cols));
ui->label_channels->setText(QString("%1").arg(_srcMat.channels()));
ui->label_depth->setText(QString("%1").arg(_srcMat.depth()));
ui->label_type->setText(QString("%1").arg(_srcMat.type()));
}
void DemoContrastAndBrightnessWidget::updateImage()
{
if(_srcImage.isNull())
{
return;
}
cv::Mat srcMat = image2Mat(_srcImage);
// 增强对比度
float r;
float g;
float b;
_dstMat = cv::Mat::zeros(srcMat.size(), srcMat.type());
int alpha = ui->horizontalSlider_alpha->value(); // 小于1，则降低对比度
int beta = ui->horizontalSlider_beta->value(); // 负数，则降低亮度
for(int row = 0; row < srcMat.rows; row++)
{
for(int col = 0; col < srcMat.cols; col++)
{
b = srcMat.at<cv::Vec3b>(row, col)[0];
g = srcMat.at<cv::Vec3b>(row, col)[1];
r = srcMat.at<cv::Vec3b>(row, col)[2];
// 对比度、亮度计算公式 cv::saturate_cast<uchar>(value)：防止溢出
_dstMat.at<cv::Vec3b>(row, col)[0] = cv::saturate_cast<uchar>(b * alpha / 100.0f + beta);
_dstMat.at<cv::Vec3b>(row, col)[1] = cv::saturate_cast<uchar>(g * alpha / 100.0f + beta);
_dstMat.at<cv::Vec3b>(row, col)[2] = cv::saturate_cast<uchar>(r * alpha / 100.0f + beta);
}
}
_dstImage = mat2Image(_dstMat);
ui->widget_image->setImage(_dstImage);
}
void DemoContrastAndBrightnessWidget::on_pushButton_openFile_clicked()
{
if(!_srcImage.load(_filePath))
{
qDebug() << __FILE__ << __LINE__ << "Failed to load image:" << _filePath;
return;
}
qDebug() << __FILE__<< __LINE__ << (int)_srcImage.format();
_srcMat = image2Mat(_srcImage);
updateInfo();
updateImage();
}
void DemoContrastAndBrightnessWidget::on_horizontalSlider_beta_sliderMoved(int position)
{
ui->spinBox_beta->setValue(position);
updateImage();
}
void DemoContrastAndBrightnessWidget::on_horizontalSlider_alpha_sliderMoved(int position)
{
ui->doubleSpinBox_alpha->setValue(position / 100.0f);
updateImage();
}
void DemoContrastAndBrightnessWidget::on_pushButton_broswer_clicked()
{
QString dir = ui->lineEdit_filePath->text();
dir = dir.mid(0, dir.lastIndexOf("/"));
QString filePath = QFileDialog::getOpenFileName(0, "打开图片", dir, "PNG;JPEG;BMP(*.png;*.jpg;*.bmp);;JPEG(*.jpg);;PNG(*.png);;BMP(*.bmp)");
if(filePath.isEmpty())
{
return;
}
_filePath = filePath;
ui->lineEdit_filePath->setText(_filePath);
}
void DemoContrastAndBrightnessWidget::on_spinBox_beta_valueChanged(int arg1)
{
ui->horizontalSlider_beta->setValue(arg1);
updateImage();
}
void DemoContrastAndBrightnessWidget::on_doubleSpinBox_alpha_valueChanged(double arg1)
{
ui->horizontalSlider_alpha->setValue(arg1 * 100);
updateImage();
}
void DemoContrastAndBrightnessWidget::on_pushButton_showFile_clicked()
{
if(_dstMat.data == 0)
{
QMessageBox::information(this, "提示", "使用opencv显示图片失败");
return;
}
cv::imshow("showFile", _dstMat);
}
void DemoContrastAndBrightnessWidget::on_pushButton_backgroundColor_clicked()
{
QColor backgroundColor = ui->widget_image->getBackgroundColor();
backgroundColor = QColorDialog::getColor(backgroundColor, this, "底色");
if(!backgroundColor.isValid())
{
return;
}
QColor color(backgroundColor.red(), backgroundColor.green(), backgroundColor.blue());
ui->widget_image->setBackgroundColor(color);
}