const double getExiv2ValueDouble(Exiv2::ExifData& exifData, Exiv2::ExifData::const_iterator it)
{
if(it!=exifData.end() && it->count())
{
return it->toFloat();
}
return 0;
};
void ImageResolution::readexiv(char const *fn) {
Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(fn);
if (!image.get())
return;
image->readMetadata();
Exiv2::ExifData &exifData = image->exifData();
if (exifData.empty())
return;
Exiv2::ExifData::const_iterator end = exifData.end();
bool havex = false;
bool havey = false;
bool haveunit = false;
int unit;
for (Exiv2::ExifData::const_iterator i = exifData.begin(); i != end; ++i) {
if (ok_)
break;
if (i->tag()==0x011a) {
// X Resolution
x_ = i->toFloat();
havex = true;
} else if (i->tag()==0x011b) {
// Y Resolution
y_ = i->toFloat();
havey = true;
} else if (i->tag()==0x0128) {
unit = i->toLong();
}
ok_ = havex && havey && haveunit;
}
if (haveunit) {
if (unit==3) {
x_ *= 2.54;
y_ *= 2.54;
}
}
ok_ = havex && havey;
}
QVariantMap QgsExifTools::readTags( const QString &imagePath )
{
std::unique_ptr< Exiv2::Image > image( Exiv2::ImageFactory::open( imagePath.toStdString() ) );
if ( !image )
return QVariantMap();
image->readMetadata();
Exiv2::ExifData &exifData = image->exifData();
if ( exifData.empty() )
{
return QVariantMap();
}
QVariantMap res;
Exiv2::ExifData::const_iterator end = exifData.end();
for ( Exiv2::ExifData::const_iterator i = exifData.begin(); i != end; ++i )
{
const QString key = QString::fromStdString( i->key() );
QVariant val;
switch ( i->typeId() )
{
case Exiv2::asciiString:
case Exiv2::string:
case Exiv2::comment:
case Exiv2::directory:
case Exiv2::xmpText:
val = QString::fromStdString( i->toString() );
break;
case Exiv2::unsignedLong:
case Exiv2::signedLong:
val = QVariant::fromValue( i->toLong() );
break;
case Exiv2::tiffDouble:
case Exiv2::tiffFloat:
val = QVariant::fromValue( i->toFloat() );
break;
case Exiv2::unsignedShort:
case Exiv2::signedShort:
val = QVariant::fromValue( static_cast< int >( i->toLong() ) );
break;
case Exiv2::unsignedRational:
case Exiv2::signedRational:
case Exiv2::unsignedByte:
case Exiv2::signedByte:
case Exiv2::undefined:
case Exiv2::tiffIfd:
case Exiv2::date:
case Exiv2::time:
case Exiv2::xmpAlt:
case Exiv2::xmpBag:
case Exiv2::xmpSeq:
case Exiv2::langAlt:
case Exiv2::invalidTypeId:
case Exiv2::lastTypeId:
val = QString::fromStdString( i->toString() );
break;
}
res.insert( key, val );
}
return res;
}
void exif_data::from_file(const std::string& filename)
{
reset();
try
{
Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(filename);
image->readMetadata();
Exiv2::ExifData &exif_data = image->exifData();
// if data is empty
if (exif_data.empty()) return;
// Exiv2 iterator in read-only
Exiv2::ExifData::const_iterator it = exif_data.end();
if ((it = exif_data.findKey(Exiv2::ExifKey("Exif.Photo.ExposureTime"))) != exif_data.end())
{
exposure_time_ = it->toFloat();
}
else if ((it = exif_data.findKey(Exiv2::ExifKey("Exif.Photo.ShutterSpeedValue"))) != exif_data.end())
{
long num = 1;
long div = 1;
float tmp = std::exp(std::log(2.0f) * it->toFloat());
if (tmp > 1)
{
div = static_cast<long>(tmp + 0.5f);
}
else
{
num = static_cast<long>(1.0f/tmp + 0.5f);
}
exposure_time_ = static_cast<float>(num)/div;
}
if ((it = exif_data.findKey(Exiv2::ExifKey("Exif.Photo.FNumber"))) != exif_data.end())
{
f_number_ = it->toFloat();
}
else if ((it = exif_data.findKey(Exiv2::ExifKey("Exif.Photo.ApertureValue"))) != exif_data.end())
{
f_number_ = static_cast<float>(expf(logf(2.0f) * it->toFloat() / 2.f));
}
// some cameras/lens DO print the fnum but with value 0, and this is not allowed for ev computation purposes.
if (f_number_ == 0.0f)
{
f_number_ = INVALID_VALUE;
}
//if iso is found use that value, otherwise assume a value of iso=100. (again, some cameras do not print iso in exif).
if ((it = exif_data.findKey(Exiv2::ExifKey("Exif.Photo.ISOSpeedRatings"))) != exif_data.end())
{
iso_speed_ = it->toFloat();
}
if ((it = exif_data.findKey(Exiv2::ExifKey("Exif.Photo.ExposureBiasValue"))) != exif_data.end())
{
ev_compensation_ = it->toFloat();
}
}
catch (Exiv2::AnyError& e)
{
return;
}
}
