/// <summary>
/// Decode raw CFAPattern value
/// </summary>
/// <remarks>
/// Converted from Exiftool version 10.33 created by Phil Harvey
/// http://www.sno.phy.queensu.ca/~phil/exiftool/
/// lib\Image\ExifTool\Exif.pm
///
/// The value consists of:
/// - Two short, being the grid width and height of the repeated pattern.
/// - Next, for every pixel in that pattern, an identification code.
/// </remarks>
private int[] DecodeCFAPattern(int tagType)
{
int[] ret;
var values = Directory.GetByteArray(tagType);
if (values == null)
{
return(null);
}
if (values.Length < 4)
{
ret = new int[values.Length];
for (var i = 0; i < values.Length; i++)
{
ret[i] = values[i];
}
return(ret);
}
IndexedReader reader = new ByteArrayReader(values);
// first two values should be read as 16-bits (2 bytes)
var item0 = reader.GetInt16(0);
var item1 = reader.GetInt16(2);
ret = new int[values.Length - 2];
var copyArray = false;
var end = 2 + item0 * item1;
if (end > values.Length) // sanity check in case of byte order problems; calculated 'end' should be <= length of the values
{
// try swapping byte order (I have seen this order different than in EXIF)
reader = reader.WithByteOrder(!reader.IsMotorolaByteOrder);
item0 = reader.GetInt16(0);
item1 = reader.GetInt16(2);
if (values.Length >= 2 + item0 * item1)
{
copyArray = true;
}
}
else
{
copyArray = true;
}
if (copyArray)
{
ret[0] = item0;
ret[1] = item1;
for (var i = 4; i < values.Length; i++)
{
ret[i - 2] = reader.GetByte(i);
}
}
return(ret);
}