VS+Qt+Halcon——显示图片，实现鼠标缩放、移动图片

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摘要

本篇博文记录一下，用VS+Qt+Halcon实现对图片的读取以及鼠标缩放，移动（鼠标事件调用了halcon自带的算子）的过程。以及遇到的坑.....

先来看一下动态效果图：

主要控件：

添加一个Label控件，对象名设为label，用于显示图片，并将背景设为黑色，设置方法为：选中Label控件，在属性编辑器中找到styleSheet属性，在其后的值中输入background-color:black即可；
添加四个Push Button控件，如上图所示从左至右，对象名依次为：btn_prePic、btn_openPic、btn_nextPic，btn_resetPic，用于打开图片和前后浏览，以及恢复原图；
添加一个Label，对象名设为label_status，用于实时显示坐标和灰度值；
将label_show控件提升为CMyLabel类，用于接收鼠标事件。

代码例程

在Visual Studio中新建一个Qt GUI项目，名称设为BrowsePic，并新建Mylabel类（继承自QLabel）用于label控件的提升。

Mylabel.h

#pragma once
#include "qlabel.h"
#include"QWheelEvent"
#include<HalconCpp.h>
using namespace HalconCpp;class Mylabel :
public QLabel
{
Q_OBJECTpublic:
Mylabel(QWidget* parent = Q_NULLPTR);
~Mylabel();
//设置Halcon图像和Halcon窗口句柄，用户响应鼠标事件后实时更新图像
void setHalconWnd(HObject img, HTuple hHalconID, QLabel* label);
//鼠标滚轮缩放事件
void wheelEvent(QWheelEvent* ev);
//鼠标按下事件
void mousePressEvent(QMouseEvent* ev);
//鼠标释放事件
void mouseReleaseEvent(QMouseEvent* ev);
//鼠标移动事件
void mouseMoveEvent(QMouseEvent* ev);
public:
HTuple m_labelID; //Qt标签句柄
HTuple m_hHalconID; //Halcon窗口句柄
HObject m_currentImg; //当前的图像
//主界面显示坐标的标签
QLabel* m_label;
//鼠标按下的位置
HTuple m_tMouseDownRow;
HTuple m_tMouseDownCol;
bool m_bIsMove; //是否移动图像标识
};

Mylabel.cpp

#include "Mylabel.h"
//定义单步放大倍率
#define ZOOMRATIO 2.0Mylabel::Mylabel(QWidget* parent)
: QLabel(parent)
{
m_bIsMove = false;
this->setMouseTracking(true);}
Mylabel::~Mylabel()
{}//设置Halcon图像和Halcon窗口句柄，用户响应鼠标事件后实时更新图像
void Mylabel::setHalconWnd(HObject img, HTuple hHalconID, QLabel* label)
{
m_hHalconID = hHalconID;
m_currentImg = img;
m_label = label;
}//鼠标滚轮缩放事件，用于缩放图像
void Mylabel::wheelEvent(QWheelEvent* ev)
{
double Zoom; //放大或缩小倍率
HTuple mouseRow, mouseCol, Button;
HTuple startRowBf, startColBf, endRowBf, endColBf, Ht, Wt, startRowAft, startColAft, endRowAft, endColAft;
//滚轮前滑，放大
if (ev->delta()>0)
{
Zoom = ZOOMRATIO;
}
else//否则缩小
{
Zoom = 1 / ZOOMRATIO;
}
//获取光标在原图上的位置，注意是原图坐标，不是Label下的坐标
HTuple hv_Exception, hv_ErrMsg;
try
{
GetMposition(m_hHalconID, &mouseRow, &mouseCol, &Button); }
catch (HException& HDevExpDefaultException)
{
return;
}
//获取原图显示的部分，注意也是原图坐标
GetPart(m_hHalconID, &startRowBf, &startColBf, &endRowBf, &endColBf);
//缩放前显示的图像宽高
Ht = endRowBf - startRowBf;
Wt = endColBf - startColBf;
//普通版halcon能处理的图像最大尺寸是32K*32K。如果无限缩小原图像，导致显示的图像超出限制，则会造成程序崩溃
if (Ht*Wt<20000*20000||Zoom==ZOOMRATIO)
{
//计算缩放后的图像区域
startRowAft = mouseRow - ((mouseRow - startRowBf) / Zoom);
startColAft = mouseCol - ((mouseCol - startColBf) / Zoom);
endRowAft = startRowAft + (Ht / Zoom);
endColAft = startColAft + (Wt / Zoom);
//如果放大过大，则返回
if (endRowAft - startRowAft < 2)
{
return;
} if (m_hHalconID != NULL)
{
//如果有图像，则先清空图像
DetachBackgroundFromWindow(m_hHalconID);
}
SetPart(m_hHalconID, startRowAft, startColAft, endRowAft, endColAft);
AttachBackgroundToWindow(m_currentImg, m_hHalconID);
}
}void Mylabel::mousePressEvent(QMouseEvent* ev)
{
HTuple mouseRow, mouseCol, Button;
try
{
GetMposition(m_hHalconID, &mouseRow, &mouseCol, &Button); }
catch (HException)
{
return;
}
//鼠标按下时的行列坐标
m_tMouseDownRow = mouseRow;
m_tMouseDownCol = mouseCol;
m_bIsMove = true;
}
//鼠标释放事件
void Mylabel::mouseReleaseEvent(QMouseEvent* ev)
{
m_bIsMove = false;
}
//鼠标移动事件
void Mylabel::mouseMoveEvent(QMouseEvent* ev)
{
HTuple startRowBf, startColBf, endRowBf, endColBf, mouseRow, mouseCol, Button;
try
{
GetMposition(m_hHalconID, &mouseRow, &mouseCol, &Button); }
catch (HException)
{
return;
}
//鼠标按下并移动时，移动图像，否则只显示坐标
if (m_bIsMove)
{
//计算移动值
double RowMove = mouseRow[0].D() - m_tMouseDownRow[0].D();
double ColMove = mouseCol[0].D() - m_tMouseDownCol[0].D();
//得到当前的窗口坐标
GetPart(m_hHalconID, &startRowBf, &startColBf, &endRowBf, &endColBf);
//移动图像
if (m_hHalconID!=NULL)
{
//如果有图像，则先清空图像
DetachBackgroundFromWindow(m_hHalconID);
}
SetPart(m_hHalconID, startRowBf - RowMove, startColBf - ColMove, endRowBf - RowMove, endColBf - ColMove);
AttachBackgroundToWindow(m_currentImg, m_hHalconID);
}
//获取灰度值
HTuple pointGray;
try
{
GetGrayval(m_currentImg, mouseRow, mouseCol, &pointGray);
}
catch (HException)
{
m_label->setText(QString::fromLocal8Bit("X坐标：- Y坐标：- 灰度值：-")); return;
}
//设置坐标
m_label->setText(QString::fromLocal8Bit("X坐标：%1 Y坐标：%2 灰度值：%3").arg(mouseCol[0].D()).arg(mouseRow[0].D()).arg(pointGray[0].D()));
}

BrowsePic.h

#pragma once#include <QtWidgets/QWidget>
#include "ui_BrowsePic.h"
#include<HalconCpp.h>
#include"qtoolbar.h"
using namespace HalconCpp;
#pragma execution_character_set("utf-8");class BrowsePic : public QWidget
{
Q_OBJECTpublic:
BrowsePic(QWidget *parent = Q_NULLPTR);
~BrowsePic();
//初始化
void init(); //显示图像
void showImg();
int currentIndex;
//显示图像的控件id
HTuple m_hLabelID; //QLabel控件句柄
HTuple m_hHalconID; //Halcon显示窗口句柄 //原始图像的尺寸
HTuple m_imgWidth, m_imgHeight; //图片路径列表
HTuple m_imgFiles; //当前图像
HObject m_hCurrentImg;
//缩放后的图像
HObject m_hResizedImg;
//缩放系数
HTuple m_hvScaledRate;
//缩放后图像的大小
HTuple m_scaledHeight, m_scaledWidth;
QToolBar* m_toolBar;
public slots: //打开图片
void on_btn_openPic_clicked(); //浏览前一张
void on_btn_prePic_clicked(); //浏览后一张
void on_btn_nextPic_clicked(); //恢复图片
void on_btn_resetPic_clicked();
private:
Ui::BrowsePicClass ui;
};

BrowsePic.cpp

#include "browsepic.h"
#include"Mylabel.h"
#include <QFileDialog>
#include <QFileInfo>
BrowsePic::BrowsePic(QWidget *parent)
: QWidget(parent)
{
ui.setupUi(this); init();}
BrowsePic::~BrowsePic()
{}void BrowsePic::init()
{
//设置halcon的文件路径为utf8，解决中文乱码
SetSystem("filename_encoding", "utf8");
//生成空图像
GenEmptyObj(&m_hCurrentImg);
m_hHalconID = NULL;
m_hLabelID = (Hlong)ui.label->winId();
currentIndex = -1;
}
//显示图像
void BrowsePic::showImg()
{
if (m_hHalconID!=NULL)
{
//如果有图像，则先清空图像
DetachBackgroundFromWindow(m_hHalconID); }
else
{
//打开窗口
OpenWindow(0, 0, ui.label->width(), ui.label->height(), m_hLabelID, "visible", "", &m_hHalconID);
}
ui.label-> setHalconWnd(m_hCurrentImg, m_hHalconID, ui.label_status); //获取图像大小
GetImageSize(m_hCurrentImg, &m_imgWidth, &m_imgHeight);
//获取缩放系数
TupleMin2(1.0 * ui.label->width() / m_imgWidth, 1.0 * ui.label->height() / m_imgHeight, &m_hvScaledRate);
//缩放图像
ZoomImageFactor(m_hCurrentImg, &m_hResizedImg, m_hvScaledRate, m_hvScaledRate, "constant");
//获取缩放后的大小
GetImageSize(m_hResizedImg, &m_scaledWidth, &m_scaledHeight);
//打开窗口
if (1.0 * ui.label->width() / m_imgWidth < 1.0 * ui.label->height() / m_imgHeight)
{
SetWindowExtents(m_hHalconID, ui.label->height() / 2.0 - m_scaledHeight / 2.0, 0, ui.label->width(), m_scaledHeight);
}
else
{
SetWindowExtents(m_hHalconID, 0, ui.label->width() / 2.0 - m_scaledWidth / 2.0, m_scaledWidth, ui.label->height()); }
SetPart(m_hHalconID, 0, 0, m_imgHeight - 1, m_imgWidth - 1);
AttachBackgroundToWindow(m_hCurrentImg, m_hHalconID);
}//打开图片
void BrowsePic::on_btn_openPic_clicked()
{
QString path = QFileDialog::getOpenFileName(this, "加载图像", "./", "图像文件(*.bmp *.png *.jpg)");
QFileInfo fileInfo(path);
QString dir = fileInfo.path(); if (!path.isEmpty())
{
ListFiles(dir.toStdString().c_str(), "files", &m_imgFiles); TupleRegexpSelect(m_imgFiles, HTuple("\\.bmp|png|jpg").Append("ignore_case"), &m_imgFiles); for (int i = 0; i < m_imgFiles.Length(); i++)
{ QString currentPath = m_imgFiles[i];
currentPath.replace("\\", "/"); if (currentPath == path)
{
currentIndex = i;
ReadImage(&m_hCurrentImg, m_imgFiles[i]);
showImg();
} }
}}//浏览前一张
void BrowsePic::on_btn_prePic_clicked()
{
if (currentIndex > 0)
{
currentIndex--;
ReadImage(&m_hCurrentImg, m_imgFiles[currentIndex]);
showImg(); }
}
//浏览后一张
void BrowsePic::on_btn_nextPic_clicked()
{
if (currentIndex >= 0 && currentIndex < m_imgFiles.Length() - 1)
{
currentIndex++;
ReadImage(&m_hCurrentImg, m_imgFiles[currentIndex]);
showImg();
}
}
//恢复图片
void BrowsePic::on_btn_resetPic_clicked()
{
showImg();
}