Re: [idn] ACE37,AMCW and LDUDE

["Soobok Lee" <lsb@postel.co.kr>]

Moreover,

codeblock shifting produces longer XOR diff in some cases:

0x5000 and 0x5f00: xor diff value = 0xf00

after codeblock shifting applied ( 0x4e00 -> 0x0000 ),

They are reduced to

0x0200 and 0x1100: xor diff value = 0x1300

diff value 0x1300 is longer than 0xf00.


codeblock shifting withOUT frequecy reordering
does not  help.

It  merely SHIFT xor diff distribution and
does NOT REDUCE the xor diff values.

I had tried it before and gave up.

Soobok Lee

----- Original Message -----
From: "Soobok Lee" <lsb@postel.co.kr>
To: "Edmon" <edmon@neteka.com>; "Keith Moore" <moore@cs.utk.edu>
 > > > I would *really* like to avoid complex reordering of codepoints,
because
> > > it would require fairly large tables (that would have to be
implemented
> > > on some machines of modest capability) and would be error-prone.
> > >
> > I agree.  The code block shifting mechanism in ACE37 however is very
> simple
> > and yeilds great benefit for CJK ideographs.
> >
>
> Code block shiffting  (  0x4E00:8FFFF ----> 0x0000: 0x52FF)
> does reduce XOR diff value  for small subset of the code points
> from   first 0x4E00 ~ 0x5E00 block.
>
> For example, 0x4e00 and 0x5000 (xor diff is 0x1e00)
> is mapped to 0x0000, 0x0200 (xir diff value 0x200 ).
>
>
> But, For 0x4e00 and 0x6e00, xor diff values are  0x2000  for either
> cases !