TASSOGRAPHY

public class Rational
{
    private int numerator;
    private int denominator;

    /// <summary>
    /// Creates an Exif Rational
    /// </summary>
    /// <param name="numerator">The value you want to store in the Rational</param>
    /// <param name="accuracy">The number of decimal places of accuracy</param>
    public Rational(double numerator, int accuracy)
    {
        accuracy = (int)Math.Pow(10, accuracy);

        this.numerator = Convert.ToInt32(Math.Abs(numerator * accuracy));
        this.denominator = accuracy;
    }

    /// <summary>
    /// Creates an Exif Rational
    /// </summary>
    /// <param name="data">A ulong typically read from exif metadata</param>
    public Rational(ulong data)
    {
        this.numerator = (int)(data & 0xFFFFFFFFL);
        this.denominator = (int)((data & 0xFFFFFFFF00000000L) >> 32);
    }

    /// <summary>
    /// Returns the Rational as a Ulong, typically used to write back to exif metadata
    /// </summary>
    /// <returns>Ulong</returns>
    public ulong ToUlong()
    {
        return ((ulong)this.numerator) | (((ulong)this.denominator) << 32);
    }

    /// <summary>
    /// Returns the Rational as an Integer
    /// </summary>
    /// <returns>Int</returns>
    public int ToInt()
    {
        return Convert.ToInt32(Math.Round(Convert.ToDouble(this.numerator) / Convert.ToDouble(this.denominator)));
    }

    /// <summary>
    /// Returns the Rational as a Double
    /// </summary>
    /// <returns>Double</returns>
    public double ToDouble()
    {
        return this.ToDouble(0);
    }

    /// <summary>
    /// Returns the Rational as a Double
    /// </summary>
    /// <returns>Double, accurate to the specified number of decimal places</returns>
    /// <param name="decimalPlaces">The number of decimal places of accuracy</param>
    public double ToDouble(int decimalPlaces)
    {
        return Math.Round(Convert.ToDouble(this.numerator) / Convert.ToDouble(this.denominator), decimalPlaces);
    }

    /// <summary>
    /// Returns the Rational as a string
    /// </summary>
    /// <returns>A string in the format numerator/denominator</returns>
    public new string ToString()
    {
        return this.numerator.ToString() + "/" + this.denominator.ToString();
    }
}

// Query for Exposure Bias
string exifExposureBias = "/app1/ifd/exif/subifd:{uint=37380}";

// Grab copy of BitmapMetadata
BitmapMetadata bitmapMetadata = StandaloneWpfReader.ReadMetadata("Test-Geotagging.jpg");

// Try parsing the value as a ulong
ulong numeric;

if (ulong.TryParse(bitmapMetadata.GetQuery(exifExposureBias).ToString(), out numeric))
{
    // Create Rational
    Rational rational = new Rational(numeric);

    // Write the ulong value back
    bitmapMetadata.SetQuery(exifExposureBias, rational.ToUlong());
}

    // Grab GpsLatitude as a ulong array
    ulong[] numerics = (ulong[])bitmapMetadata.GetQuery("/app1/ifd/Gps/subifd:{uint=2}");