//for diagnostic
void PrintTag(Exiv2::ExifData::iterator itr)
{
std::cout << itr->value() << " (" << itr->typeName() << ", size: " << itr->count() << ")" << std::endl;
if(itr->count()>1)
{
std::cout << "[";
for(long i=0; i<itr->count(); i++)
{
std::cout << itr->toFloat(i) << ",";
}
std::cout << "]" << std::endl;
};
};
QString Previewimage::getExifKey(QString key, Exiv2::ExifData *exifData){
// returns string represented by exif key
if(exifData == 0) return QString();
QString ret;
try {
Exiv2::ExifData::iterator pos = exifData->findKey(
Exiv2::ExifKey(qPrintable(key)));
if (pos == exifData->end()) return QString();
else ret = QString().fromStdString(pos->value().toString());
} catch (Exiv2::Error& e) {
qCritical("[Rename] %s", e.what());
}
return ret;
}
// *****************************************************************************
// Main
int main()
try {
// Container for all metadata
Exiv2::ExifData exifData;
// *************************************************************************
// Add to the Exif data
// Create a ASCII string value (note the use of create)
Exiv2::Value* v = Exiv2::Value::create(Exiv2::asciiString);
// Set the value to a string
v->read("1999:12:31 23:59:59");
// Add the value together with its key to the Exif data container
Exiv2::ExifKey key("Exif.Photo.DateTimeOriginal");
exifData.add(key, v);
std::cout << "Added key \"" << key << "\", value \"" << *v << "\"\n";
// Delete the memory allocated by Value::create
delete v;
// Now create a more interesting value (without using the create method)
Exiv2::URationalValue* rv = new Exiv2::URationalValue;
// Set two rational components from a string
rv->read("1/2 1/3");
// Add more elements through the extended interface of rational value
rv->value_.push_back(std::make_pair(2,3));
rv->value_.push_back(std::make_pair(3,4));
// Add the key and value pair to the Exif data
key = Exiv2::ExifKey("Exif.Image.PrimaryChromaticities");
exifData.add(key, rv);
std::cout << "Added key \"" << key << "\", value \"" << *rv << "\"\n";
// Delete memory allocated on the heap
delete rv;
// *************************************************************************
// Modify Exif data
// Find the timestamp metadatum by its key
key = Exiv2::ExifKey("Exif.Photo.DateTimeOriginal");
Exiv2::ExifData::iterator pos = exifData.findKey(key);
if (pos == exifData.end()) throw Exiv2::Error("Key not found");
// Modify the value
std::string date = pos->toString();
date.replace(0,4,"2000");
pos->setValue(date);
std::cout << "Modified key \"" << key
<< "\", new value \"" << pos->value() << "\"\n";
// Find the other key
key = Exiv2::ExifKey("Exif.Image.PrimaryChromaticities");
pos = exifData.findKey(key);
if (pos == exifData.end()) throw Exiv2::Error("Key not found");
// Get a pointer to a copy of the value
v = pos->getValue();
// Downcast the Value pointer to its actual type
rv = dynamic_cast<Exiv2::URationalValue*>(v);
if (rv == 0) throw Exiv2::Error("Downcast failed");
// Modify the value directly through the interface of URationalValue
rv->value_[2] = std::make_pair(88,77);
// Copy the modified value back to the metadatum
pos->setValue(rv);
// Delete the memory allocated by getValue
delete v;
std::cout << "Modified key \"" << key
<< "\", new value \"" << pos->value() << "\"\n";
// *************************************************************************
// Delete metadata from the Exif data container
// Delete the metadatum at iterator position pos
key = Exiv2::ExifKey("Exif.Image.PrimaryChromaticities");
pos = exifData.findKey(key);
if (pos == exifData.end()) throw Exiv2::Error("Key not found");
exifData.erase(pos);
std::cout << "Deleted key \"" << key << "\"\n";
// *************************************************************************
// Finally, write the remaining Exif data to an image file
int rc = exifData.write("img_2158.jpg");
if (rc) {
std::string error = Exiv2::ExifData::strError(rc, "img_2158.jpg");
throw Exiv2::Error(error);
}
return 0;
}
catch (Exiv2::Error& e) {
std::cout << "Caught Exiv2 exception '" << e << "'\n";
return -1;
}
QgsPoint QgsExifTools::getGeoTag( const QString &imagePath, bool &ok )
{
ok = false;
if ( !QFileInfo::exists( imagePath ) )
return QgsPoint();
try
{
std::unique_ptr< Exiv2::Image > image( Exiv2::ImageFactory::open( imagePath.toStdString() ) );
if ( !image )
return QgsPoint();
image->readMetadata();
Exiv2::ExifData &exifData = image->exifData();
if ( exifData.empty() )
return QgsPoint();
Exiv2::ExifData::iterator itLatRef = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLatitudeRef" ) );
Exiv2::ExifData::iterator itLatVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLatitude" ) );
Exiv2::ExifData::iterator itLonRef = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLongitudeRef" ) );
Exiv2::ExifData::iterator itLonVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLongitude" ) );
if ( itLatRef == exifData.end() || itLatVal == exifData.end() ||
itLonRef == exifData.end() || itLonVal == exifData.end() )
return QgsPoint();
auto readCoord = []( const QString & coord )->double
{
double res = 0;
double div = 1;
const QStringList parts = coord.split( QRegularExpression( QStringLiteral( "\\s+" ) ) );
for ( const QString &rational : parts )
{
const QStringList pair = rational.split( '/' );
if ( pair.size() != 2 )
break;
res += ( pair[0].toDouble() / pair[1].toDouble() ) / div;
div *= 60;
}
return res;
};
auto readRationale = []( const QString & rational )->double
{
const QStringList pair = rational.split( '/' );
if ( pair.size() != 2 )
return std::numeric_limits< double >::quiet_NaN();
return pair[0].toDouble() / pair[1].toDouble();
};
double lat = readCoord( QString::fromStdString( itLatVal->value().toString() ) );
double lon = readCoord( QString::fromStdString( itLonVal->value().toString() ) );
const QString latRef = QString::fromStdString( itLatRef->value().toString() );
const QString lonRef = QString::fromStdString( itLonRef->value().toString() );
if ( latRef.compare( QLatin1String( "S" ), Qt::CaseInsensitive ) == 0 )
{
lat *= -1;
}
if ( lonRef.compare( QLatin1String( "W" ), Qt::CaseInsensitive ) == 0 )
{
lon *= -1;
}
ok = true;
Exiv2::ExifData::iterator itElevVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSAltitude" ) );
Exiv2::ExifData::iterator itElevRefVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSAltitudeRef" ) );
if ( itElevVal != exifData.end() )
{
double elev = readRationale( QString::fromStdString( itElevVal->value().toString() ) );
if ( itElevRefVal != exifData.end() )
{
const QString elevRef = QString::fromStdString( itElevRefVal->value().toString() );
if ( elevRef.compare( QLatin1String( "1" ), Qt::CaseInsensitive ) == 0 )
{
elev *= -1;
}
}
return QgsPoint( lon, lat, elev );
}
else
{
return QgsPoint( lon, lat );
}
}
catch ( ... )
{
return QgsPoint();
}
}
