public static GpsHelper FromDouble(double angleInDegrees)
{
//ensure the value will fall within the primary range [-180.0..+180.0]
while (angleInDegrees < -180.0)
{
angleInDegrees += 360.0;
}
while (angleInDegrees > 180.0)
{
angleInDegrees -= 360.0;
}
var result = new GpsHelper {
IsNegative = angleInDegrees < 0
};
//switch the value to positive
angleInDegrees = Math.Abs(angleInDegrees);
//gets the degree
result.Degrees = (int)Math.Floor(angleInDegrees);
var delta = angleInDegrees - result.Degrees;
//gets minutes and seconds
var seconds = (int)Math.Floor(3600.0 * delta);
result.Seconds = seconds % 60;
result.Minutes = (int)Math.Floor(seconds / 60.0);
delta = delta * 3600.0 - seconds;
//gets fractions
result.Milliseconds = (int)(1000.0 * delta);
return(result);
}
public static void SetMetadata(string imgSourcePath, string metadata, bool fixImageOrientation = true)
{
var saveimage = false;
try
{
ImageFile fileInfo;
try
{
//Retrieve current known metadata for the image
fileInfo = ImageFile.FromFile(imgSourcePath);
}
catch //Most likely this type of image is either not supported by the Exif library or does not have any Exif information
{
return;
}
if (!string.IsNullOrWhiteSpace(metadata))
{
var defaultProperties = fileInfo.Properties.Count;
//Iterate through all properties to be set on the image
foreach (var geoElement in JObject.Parse(metadata))
{
//Current new property has a valid value?
if (!string.IsNullOrEmpty(geoElement.Value.Value <string>()))
{
//Is the current geolocation element supported?
if (Geoloc2ExifPropertyMapper.ContainsKey(geoElement.Key))
{
//Get current EXIF tag for the current geolocation property
var currentExifTag = (ExifTag)Geoloc2ExifPropertyMapper[geoElement.Key];
var exifProperty =
fileInfo.Properties.FirstOrDefault(p =>
p.IFD == IFD.GPS && p.Tag == currentExifTag);
//Image does not contain this property in the metadata
if (exifProperty == null)
{
switch (currentExifTag)
{
case ExifTag.GPSLatitude:
var lat = GpsHelper.FromDouble(geoElement.Value.Value <double>());
var newLatProperty = new GPSLatitudeLongitude(ExifTag.GPSLatitude,
lat.Degrees, lat.Minutes, lat.Seconds);
fileInfo.Properties.Add(newLatProperty);
var newLatRefProperty = new ExifAscii(ExifTag.GPSLatitudeRef,
geoElement.Value.Value <double>() > 0 ? "N" : "S", Encoding.ASCII);
fileInfo.Properties.Add(newLatRefProperty);
break;
case ExifTag.GPSLongitude:
var lng = GpsHelper.FromDouble(geoElement.Value.Value <double>());
var newLongProperty = new GPSLatitudeLongitude(ExifTag.GPSLongitude,
lng.Degrees, lng.Minutes, lng.Seconds);
fileInfo.Properties.Add(newLongProperty);
var newLongRefProperty = new ExifAscii(ExifTag.GPSLongitudeRef,
geoElement.Value.Value <double>() > 0 ? "E" : "W", Encoding.ASCII);
fileInfo.Properties.Add(newLongRefProperty);
break;
case ExifTag.GPSDOP:
var newDopProperty = new ExifSRational(ExifTag.GPSDOP,
new MathEx.Fraction32(geoElement.Value.Value <double>()));
fileInfo.Properties.Add(newDopProperty);
break;
case ExifTag.GPSAltitude:
var newAltitudeProperty = new ExifSRational(ExifTag.GPSAltitude,
new MathEx.Fraction32(geoElement.Value.Value <double>()));
fileInfo.Properties.Add(newAltitudeProperty);
var newAltitudeRefProperty = new ExifByte(ExifTag.GPSAltitudeRef, 0);
fileInfo.Properties.Add(newAltitudeRefProperty);
break;
case ExifTag.GPSSpeed:
var newSpeedProperty = new ExifSRational(ExifTag.GPSSpeed,
new MathEx.Fraction32(
geoElement.Value.Value <double>() * 3.6)); //Convert to Km/h
fileInfo.Properties.Add(newSpeedProperty);
if (fileInfo.Properties.All(p => p.Name != ExifTag.GPSSpeedRef.ToString()))
{
var newSpeedRefProperty = new ExifAscii(ExifTag.GPSSpeedRef, "K",
Encoding.ASCII); //Km/h
fileInfo.Properties.Add(newSpeedRefProperty);
}
break;
case ExifTag.GPSImgDirection:
var newDirectionProperty = new ExifSRational(ExifTag.GPSImgDirection,
new MathEx.Fraction32(geoElement.Value.Value <double>()));
fileInfo.Properties.Add(newDirectionProperty);
if (fileInfo.Properties.All(p =>
p.Name != ExifTag.GPSImgDirectionRef.ToString()))
{
var newDirectionRefProperty = new ExifAscii(ExifTag.GPSImgDirectionRef,
"T", Encoding.ASCII); //True North
fileInfo.Properties.Add(newDirectionRefProperty);
}
break;
}
}
}
}
}
//Set additional information in EXIF header
if (defaultProperties < fileInfo.Properties.Count)
{
saveimage = true;
if (fileInfo.Properties.FirstOrDefault(p => p.Name == ExifTag.Software.ToString()) == null)
{
var newSoftwaredProperty = new ExifAscii(ExifTag.Software, ExifDefaultSoftware, Encoding.ASCII);
fileInfo.Properties.Add(newSoftwaredProperty);
}
if (fileInfo.Properties.FirstOrDefault(p => p.Name == ExifTag.GPSDateStamp.ToString()) == null)
{
var newDateStampProperty = new ExifAscii(ExifTag.GPSDateStamp, DateTime.Now.Date.ToString("yyyy:MM:dd"), Encoding.ASCII);
fileInfo.Properties.Add(newDateStampProperty);
}
if (fileInfo.Properties.FirstOrDefault(p => p.Name == ExifTag.GPSTimeStamp.ToString()) == null)
{
var newTimeStampProperty = new GPSLatitudeLongitude(ExifTag.GPSTimeStamp, DateTime.Now.Hour, DateTime.Now.Minute, DateTime.Now.Second);
fileInfo.Properties.Add(newTimeStampProperty);
}
}
}
//Image orientation needs correction?
if (fixImageOrientation)
{
var imgOrientation = fileInfo.Properties.FirstOrDefault(i => i.Name == ExifTag.Orientation.ToString());
if (imgOrientation != null)
{
var orientationValue = BitConverter.ToUInt16(imgOrientation.Interoperability.Data, 0);
if (orientationValue != (int)RotateFlipType.RotateNoneFlipNone)
{
var rotateFlipType = GetRotateFlipTypeByExifOrientationData(orientationValue);
if (rotateFlipType != RotateFlipType.RotateNoneFlipNone)
{
//Get copy of current exif data from original image
var exifData = fileInfo.Properties.ToArray();
//Remove thumbnail related data from original image
foreach (var thumbData in exifData.Where(p => p.IFD == IFD.First || p.IFD == IFD.JFIF).ToArray())
{
fileInfo.Properties.Remove(thumbData);
}
SaveImageFileWithRetry(fileInfo, imgSourcePath);
//Flip image
using (var img = Image.FromFile(imgSourcePath))
{
var encoderParams = new EncoderParameters
{
Param = { [0] = new EncoderParameter(Encoder.Quality, 90L) }
};
img.RotateFlip(rotateFlipType);
img.RemovePropertyItem((int)ExifTag.Orientation - (int)IFD.Zeroth);
img.Save(imgSourcePath, GetEncoder(ImageFormat.Jpeg), encoderParams);
saveimage = false;
}
}
}
}
}
//Save changes in EXIF header
if (saveimage)
{
SaveImageFileWithRetry(fileInfo, imgSourcePath);
}
}
catch (Exception ex)
{
throw new Exception("Error in ACTransit.Framework.Imaging.SetMetadata", ex);
}
}
