/// <summary>
/// Calculates the floating point value of this IFD.
/// </summary>
/// <returns>The value of this IFD as a float.</returns>
public double AsDecimal()
{
int numerator = TIFFHeader.ToInt32(Buffer, OffsetToValue, IsLittleEndian);
int denominator = TIFFHeader.ToInt32(Buffer, OffsetToValue + 4, IsLittleEndian);
return(Exif.Rational(numerator, denominator));
}
/// <summary>
/// Parses the bytes specified as an InteroperabilityField.
/// </summary>
/// <param name="buffer">The buffer containing the data.</param>
/// <param name="offset">The offset into the buffer to begin parsing.</param>
/// <param name="little_endian">When true, integers are in little endian format, when false integers are in big endian format.</param>
/// <returns>An InteroperabilityField object.</returns>
public static InteroperabilityField FromBytes(byte[] buffer, int offset, bool little_endian)
{
var return_value = new InteroperabilityField();
return_value.IsLittleEndian = little_endian;
return_value.Tag = TIFFHeader.ToUInt16(buffer, offset, little_endian);
return_value.Type = TIFFHeader.ToUInt16(buffer, offset + 2, little_endian);
return_value.Count = TIFFHeader.ToInt32(buffer, offset + 4, little_endian);
return_value.OffsetToValue = TIFFHeader.ToInt32(buffer, offset + 8, little_endian);
return_value.Byte0 = buffer[offset + 8];
return_value.Byte1 = buffer[offset + 9];
return_value.Byte2 = buffer[offset + 10];
return_value.Byte3 = buffer[offset + 11];
return_value.Buffer = buffer;
return(return_value);
}
public double DecimalValue(ImageFileDirectory ifd, int tag, byte[] buffer)
{
if (buffer == null || ifd == null)
{
return(0.0D);
}
var field = ifd.GetTag(tag);
if (field == null || field.Type != 5)
{
return(0.0D);
}
int numerator = TIFFHeader.ToInt32(buffer, field.OffsetToValue, Header.LittleEndian);
int denominator = TIFFHeader.ToInt32(buffer, field.OffsetToValue + 4, Header.LittleEndian);
double return_value = Rational(numerator, denominator);
return(return_value);
}
public bool GPSTime(ImageFileDirectory ifd, int tag, out double hours, out double minutes, out double seconds)
{
hours = 0.0D;
minutes = 0.0D;
seconds = 0.0D;
if (TIFFData == null || ifd == null)
{
return(false);
}
var field = ifd.GetTag(tag);
if (field == null || field.Type != 5)
{
return(false);
}
if (field.Count < 3)
{
return(false);
}
int[] integer_array = new int[field.Count * 2]; // Rationals are two integers each
int array_index = 0;
while (array_index < integer_array.Length)
{
integer_array[array_index] = TIFFHeader.ToInt32(TIFFData, field.OffsetToValue + (array_index * 4), Header.LittleEndian);
array_index++;
}
hours = Rational(integer_array[0], integer_array[1]);
minutes = Rational(integer_array[2], integer_array[3]);
seconds = Rational(integer_array[4], integer_array[5]);
return(true);
}
public bool FromBytes(byte[] buffer, int offset, bool little_endian)
{
Empty();
if (buffer == null || offset < 0 || buffer.Length < 6)
{
return(false);
}
int number_of_entries = TIFFHeader.ToUInt16(buffer, offset, little_endian);
if (number_of_entries > 5460) // 5461 entries in 64KB buffer
{
return(false);
}
Fields = new InteroperabilityField[number_of_entries];
string tag_name = string.Empty;
int entry_index = 0;
while (entry_index < number_of_entries)
{
Fields[entry_index] = InteroperabilityField.FromBytes(buffer, offset + 2 + (entry_index * 12), little_endian);
if (TagNames != null && TagNames.TryGetValue(Fields[entry_index].Tag, out tag_name) == true)
{
Fields[entry_index].TagName = tag_name;
}
entry_index++;
}
NextOffset = TIFFHeader.ToInt32(buffer, offset + 2 + (number_of_entries * 12), little_endian);
return(true);
}
public double DegreesValue(ImageFileDirectory ifd, int tag)
{
if (TIFFData == null || ifd == null)
{
return(0.0D);
}
InteroperabilityField field = ifd.GetTag(tag);
if (field == null || (field.Type != 5 && field.Type != 10))
{
return(0.0D);
}
if (field.Count < 3)
{
return(0.0D);
}
int[] integer_array = new int[field.Count * 2]; // Rationals are two integers each
int array_index = 0;
while (array_index < integer_array.Length)
{
integer_array[array_index] = TIFFHeader.ToInt32(TIFFData, field.OffsetToValue + (array_index * 4), Header.LittleEndian);
array_index++;
}
double degrees = Rational(integer_array[0], integer_array[1]);
double minutes = Rational(integer_array[2], integer_array[3]);
double seconds = Rational(integer_array[4], integer_array[5]);
double return_value = ConvertDegreesMinutesSecondsCoordinateToDecimalDegrees(degrees, minutes, seconds);
return(return_value);
}
