读取TIF文件经纬度

源代码：

//tifinfo.h
void getGeoTransform(const QString path, double *value);

private:
    Ui::TifInfoClass ui;
    QString m_previousDir;//记录上次打开的文件夹
    QString m_Path;//文件路径
    GDALDataset *m_Dataset;
private slots:
    void selBtnClickedSlot();
    void calcBtnClickedSlot();

//tifinfo.cpp
TifInfo::TifInfo(QWidget *parent)
    : QDialog(parent)
{
    ui.setupUi(this);
    this->setFixedSize(600, 400);
    m_Path = "";
    m_previousDir = "\.";
    connect(ui.selBtn, SIGNAL(clicked()), this, SLOT(selBtnClickedSlot()));
    connect(ui.calcBtn, SIGNAL(clicked()), this, SLOT(calcBtnClickedSlot()));
}
TifInfo::~TifInfo()
{
}
void TifInfo::selBtnClickedSlot()
{
    m_Path = QFileDialog::getOpenFileName(this, "选择文件", m_previousDir, "Files (*.tif)");
    if (m_Path.isEmpty()) return;
    QFileInfo fInfo(m_Path);
    m_previousDir = fInfo.absolutePath();
    ui.pathEdt->setText(m_Path);
}
void TifInfo::calcBtnClickedSlot()
{
    if (m_Path.isEmpty()) return;
    double value[6];
    getGeoTransform(m_Path, value);
    QFileInfo fInfo(m_Path);
    QString showStr = "";
    showStr.append(fInfo.fileName() + " :\n");
    showStr.append("左上:  " + QString::number(value[1], 'f', 12) + "  ,  " + QString::number(value[0], 'f', 12) + "\n");
    showStr.append("右上:  " + QString::number(value[1], 'f', 12) + "  ,  " + QString::number(value[2], 'f', 12) + "\n");
    showStr.append("左下:  " + QString::number(value[3], 'f', 12) + "  ,  " + QString::number(value[0], 'f', 12) + "\n");
    showStr.append("右下:  " + QString::number(value[3], 'f', 12) + "  ,  " + QString::number(value[2], 'f', 12) + "\n");
    ui.textBrowser->append(showStr);
    m_Path = "";
}
void TifInfo::getGeoTransform(const QString path, double *value)
{
    GDALAllRegister();
    CPLSetConfigOption("GDAL_FILENAME_IS_UTF8", "NO");
    m_Dataset = (GDALDataset *)GDALOpen(path.toStdString().c_str(), GA_ReadOnly);
    if (m_Dataset == NULL)
    {
	ui.textBrowser->append("无法打开文件！");
	return;
    }
    double adfGeoTransform[6];
    int XSize = m_Dataset->GetRasterXSize();
    int YSize = m_Dataset->GetRasterYSize();
    int imgFixedWidth = 3000;
    if (m_Dataset->GetGeoTransform(adfGeoTransform) == CE_None)
    {
	value[0] = adfGeoTransform[0];
	value[1] = adfGeoTransform[3];
	value[2] = adfGeoTransform[1] * (double)XSize + adfGeoTransform[0];
	value[3] = adfGeoTransform[5] * (double)YSize + adfGeoTransform[3];
	value[4] = imgFixedWidth;
	value[5] = (imgFixedWidth*YSize) / XSize;

	if (value[0] > 180 || value[0] < -180)//墨卡托转WGS84
	{
		value[0] = Mercator2Lon(value[0]);
		value[1] = Mercator2Lat(value[1]);
		value[2] = Mercator2Lon(value[2]);
		value[3] = Mercator2Lat(value[3]);
	}
    }
    GDALClose(m_Dataset);
}

//GlobalFunction.h
#include <QtMath>

static double Mercator2Lon(double lon)//墨卡托转WGS84:经度
{
    return lon / 20037508.34 * 180.0;
}
static double Mercator2Lat(double lat)//墨卡托转WGS84:纬度
{
    double result = 0;
    double mid = lat / 20037508.34 * 180.0;
    result = 180.0 / M_PI*(2.0 * qAtan(qExp(mid*M_PI / 180.0)) - M_PI / 2.0);
    return result;
}

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