本例子将800*600的double类型的数据先进行归一化成0-255的quint8类型的数据，然后将归一化后的数据生成一个QImage，这个QImage的格式一定要是
QImage::Format_Indexed8
这是为了方便使用自定义的颜色表，然后将qimage放到qlabel中显示，效果如下：
主要代码如下：
头文件：
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
void initRGBTable();
void findMaxMin(QVector<double> vData, double &fMax, double &fMin);
QVector<QRgb> m_vecGrayTable;//灰度图颜色表
QVector<QRgb> m_vecColorTable;//彩色图颜色表
QVector<double> m_vData;
int m_nWidth;
int m_nHeight;
private slots:
void on_pushButton_2_clicked();
void on_pushButton_clicked();
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
源文件：
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
m_nWidth = 800;
m_nHeight = 600;
m_vData.resize(800*600);
for(int i = 0;i<m_nHeight;i++)
{
for(int j = 0;j<m_nWidth;j++)
{
m_vData[i*m_nWidth+j]=j+0.5;
}
}
initRGBTable();//初始化颜色表
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_pushButton_2_clicked()//show gray img
{
double fMax=0.0;
double fMin=0.0;
findMaxMin(m_vData,fMax,fMin);
double fDifference = fMax - fMin;
QVector<quint8> vnData;
vnData.resize(m_vData.size());
if(fDifference != 0)
{
for(int i = 0;i<m_nHeight;i++)
{
for(int j = 0;j<m_nWidth;j++)
{
vnData[i*m_nWidth+j] = static_cast<int>((m_vData.value(i*m_nWidth+j)-fMin)*1.0f/fDifference*255);
}
}
}
QImage img((uchar*)(&vnData[0]),m_nWidth,m_nHeight,QImage::Format_Indexed8);
img.setColorTable(m_vecGrayTable);
QPixmap qPix = QPixmap::fromImage(img);
qPix.scaled(ui->label->size(), Qt::KeepAspectRatio);
ui->label->setPixmap(qPix);
}
void MainWindow::findMaxMin(QVector vData, double &fMax, double &fMin)
{
if(vData.size()>1)
{
fMax = vData.value(0);
fMin = fMax;
for(int i=1;i<vData.size();i++)
{
if(fMax<vData.value(i))
{
fMax = vData.value(i);
}
if(fMin>vData.value(i))
{
fMin = vData.value(i);
}
}
}
}
void MainWindow::initRGBTable()
{
m_vecGrayTable.clear();
m_vecColorTable.clear();
int r;
int g;
int b;
int nTemp;
for(int i=0;i<256;i++)
{
//初始化灰度图颜色表
m_vecGrayTable<<(i+i*0x100+i*0x10000+0xff000000);
//初始化伪彩图颜色表
if(i<=51)
{
r = 255;
g = i*5;
b = 0;
}
else if(i<=102)
{
nTemp = i-51;
r = 255-nTemp*5;
g = 255;
b = 0;
}
else if(i<=153)
{
nTemp = i-102;
r = 0;
g = 255;
b = nTemp*5;
}
else if(i<=204)
{
nTemp = i-153;//51
r = 0;
g = 255-(qint8)(nTemp*127.0/51+0.5);
b = 255;
}
else if(i<=255)
{
nTemp = i-204;
r = 0;
g = 127-(qint8)(nTemp*127.0/51+0.5);
b = 255;
}
QColor c(r,g,b);
m_vecColorTable.insert(0,c.rgb());
//m_vecColorTable.append(c.rgb());
}
}
void MainWindow::on_pushButton_clicked()
{
double fMax=0.0;
double fMin=0.0;
findMaxMin(m_vData,fMax,fMin);
double fDifference = fMax - fMin;
QVector<quint8> vnData;
vnData.resize(m_vData.size());
if(fDifference != 0)
{
for(int i = 0;i<m_nHeight;i++)
{
for(int j = 0;j<m_nWidth;j++)
{
vnData[i*m_nWidth+j] = static_cast<int>((m_vData.value(i*m_nWidth+j)-fMin)*1.0f/fDifference*255);
}
}
}
QImage img((uchar*)(&vnData[0]),m_nWidth,m_nHeight,QImage::Format_Indexed8);
img.setColorTable(m_vecColorTable);
QPixmap qPix = QPixmap::fromImage(img);
qPix.scaled(ui->label->size(), Qt::KeepAspectRatio);
ui->label->setPixmap(qPix);
}
mainwindow.ui:
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>MainWindow</class>
<widget class="QMainWindow" name="MainWindow">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>947</width>
<height>562</height>
</rect>
</property>
<property name="windowTitle">
<string>MainWindow</string>
</property>
<widget class="QWidget" name="centralwidget">
<layout class="QHBoxLayout" name="horizontalLayout">
<item>
<layout class="QVBoxLayout" name="verticalLayout">
<item>
<widget class="QPushButton" name="pushButton_2">
<property name="maximumSize">
<size>
<width>100</width>
<height>16777215</height>
</size>
</property>
<property name="text">
<string>ShowGray</string>
</property>
</widget>
</item>
<item>
<widget class="QPushButton" name="pushButton">
<property name="maximumSize">
<size>
<width>100</width>
<height>16777215</height>
</size>
</property>
<property name="text">
<string>ShowColor</string>
</property>
</widget>
</item>
</layout>
</item>
<item>
<widget class="QLabel" name="label">
<property name="text">
<string/>
</property>
</widget>
</item>
</layout>
</widget>
<widget class="QMenuBar" name="menubar">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>947</width>
<height>26</height>
</rect>
</property>
</widget>
<widget class="QStatusBar" name="statusbar"/>
</widget>
<resources/>
<connections/>
</ui>
.pro文件如下：
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
CONFIG += c++11
# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0
SOURCES += \
main.cpp \
mainwindow.cpp
HEADERS += \
mainwindow.h
FORMS += \
mainwindow.ui
# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target
