[brailleblaster] Re: Thoughts on backtranslating braille to print

  • From: Larry Skutchan <lskutchan@xxxxxxx>
  • To: "brailleblaster@xxxxxxxxxxxxx" <brailleblaster@xxxxxxxxxxxxx>
  • Date: Sun, 26 Jan 2014 13:50:49 +0000

Thanks for your valueable input, Susan. It sounds like you have quite the 
experience. Maybe we really don't need to back translate. After all, the real 
problem is getting content into accurate Braille, not the other way around. 
There are, however, times when a transcriber will want to enter Braille 
directly. Think of the case where a title might actually be teaching a Braille 
code. An automated translation could not possibly occur without some specific 
help. There is, however, probably not really a need to reverse translate that 
note.
Thanks so much for your insightful thoughts.

-----Original Message-----
From: brailleblaster-bounce@xxxxxxxxxxxxx 
[mailto:brailleblaster-bounce@xxxxxxxxxxxxx] On Behalf Of Susan Jolly
Sent: Friday, January 24, 2014 1:49 PM
To: brailleblaster@xxxxxxxxxxxxx
Subject: [brailleblaster] Thoughts on backtranslating braille to print

As some of you know, I spent quite a few years working to develop accurate 
backtranslators for EBAE and for Nemeth.  Automating accurate interpretion of 
braille is a difficult problem because all of the braille systems I am familiar 
with have context-sensitive grammars and usually at least a few ambiguities as 
well.  Human braille readers are able to use common sense to resolve ambiguites 
such as the EBAE translation of the word "bumblebee." 
Humans are also aware of the implicit scoping rules for indicators.

If all one is interested in is a so-called roundtrip, that is, print to braille 
and back to print, there are various strategies for retaining the necessary 
information.  BrailleBlaster uses LiblouisUTDML for this purpose. 
MegaDots retains what it calls hints in order to provide an accurate roundtrip 
for EBAE.  I use my extended braille or what I sometimes call Dotless braille.

However, if one needs accurate backtranslation of braille which has been either 
directly entered or for which there is no associated roundtrip information, 
this requires the use of appropriate algorithms such as parsing based on the 
grammar of the particular braille system.  I've never been able to think of any 
general method for backtranslating braille without a grammar.  It may be that 
it is possible to automate the development of a grammar from a translation 
table but I haven't tried to do this.

I know that backtranslation software for certain braille systems is built into 
braille displays.  However, as far as I know, none of these apps have the 
sophistication necessary for the accurate backtranslation of textbooks and 
other complex documents that brailleblaster is intended to handle.

Based on my experience, I would consider the development of an accurate 
backtranslation capability as a separate or follow-on project.  I would also 
revisit alternatives to the immediate need for this capability.  For example, I 
don't understand why transcribers can't enter transcriber notes in print.  
After all, EPUB already has information, such as the contents of alt tags, that 
is intended for a certain audience.

I'm glad to answer any questions about this issue.

Best wishes,
Susan Jolly 



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