/// <summary>
/// Get orientation information from jpeg input stream.
/// </summary>
/// <param name="inputStream">
/// The input stream of jpeg image.
/// </param>
/// <returns>
/// Orientation: 1/8/3/6.
/// Returns 0 if there is no valid orientation information.
/// </returns>
public static int GetOrientation(Stream inputStream)
{
try
{
int length = MoveToAPP1EXIF(inputStream);
if (length == 0)
{
return(0); // unknown orientation
}
return(TiffUtil.ReadOrientationFromTIFF(inputStream, length));
}
catch (IOException)
{
return(0);
}
}
/// <summary>
/// Determines auto-rotate angle based on orientation information.
/// </summary>
/// <param name="orientation">
/// Orientation information, one of {1, 3, 6, 8}.
/// </param>
/// <returns>
/// Orientation: 1/3/6/8 -> 0/180/90/270.
/// </returns>
public static int GetAutoRotateAngleFromOrientation(int orientation)
{
return(TiffUtil.GetAutoRotateAngleFromOrientation(orientation));
}