OS: windows 7 64 bit
I've updated my scancode to the latest version available.
file : dhash.txt

scancode output :

Path                                 What   Start Line  End Line        Info
C:/doc/temporary/issue_files/dhash.h    License    6    6       Public Domain

In the above file the correct license text seems to be from line 11 to 22 which is LGPL 3.0 or Later but the license public domain is detected and the LGPL 3.0 or Later license text is ignored.

file : dhash_example.txt
In the above file license text for LGPL 3.0 or Later is available from lines 7 to 18 but there were no results from scancode.