[BlindRUG] Sharing Successful Braille Labelling Test

[Godfrey, Jonathan]

Hello JooYoung et al.,

I’m pleased you’ve made it this far in such a short time.

Saving as pdf might be as simple as using savePlot(…, type=”pdf”) but there may be some trouble with respect to the way the braille font gets incorporated into the graphic window.

I’m going to offer a very simplified version of the truth with respect to images and their implementation in R and how it affects us.

There are three types of image. Raister images are ones that embed absolutely no information except what colour each coordinate point should be. This includes all the standard file types used for things like photos (jpg, png, bmp, gif…). A letter is not a character but a series of dots put alongside one another that look like they are joined.

The second type is vector graphics where information is stored as lines wherever possible. The most well-known is the encapsulated post script (eps) file commonly used by latex documents. The usually dreaded pdf files can be of this type as well, but for all sorts of reasons, the way a pdf stores information like text strings can vary quite dramatically. One common problem is the failure to keep a word together as one string and render it as separate letters (a problem not unique to pdf). For the reason of inconsistency,  I would ask why you want to work using pdf’s.

The scalable vector graphic might prove to be a much more versatile option. The SVG format will allow inclusion of raister images as subparts of the main SVG file. We still won’t be able to read the text stored in the raister elements though. The use of a solution that does not embed the braille in a raister element will be better. I’d like to use the ViewPlus braille fonts for this reason as they appear as letters in print, but braille when embossed on a Tiger embosser. (Not much help for non-Tiger users)

The next major problem with graphics in R is that there are two basic systems for creating them. The traditional graphics window is built using the graphics package, while many other packages use the alternative “grid” system. The grid system is the brain child of Paul Murrell at the University of Auckland here in NZ. I’ve been working with Paul on a number of ideas over the last 18 months and converting images to the grid system is one thing we will need for improving the tactile images we want. Paul has created a package that converts the traditional graphics device to a grid device. Following that conversion, we can export the grid graphic to an SVG file. I’m working on this at present. Our experimentation to date includes conversion of some maps and the histogram example JooYoung has used. We have shown that it is possible to add the text description of a histogram to the SVG file so that these details can be picked up by the right viewing software. This is quite futuristic at present, so please don’t get too excited.

Editing an SVG is considerably easier than editing a pdf or a raister image, but the editing software I have seen is principally designed for a sighted user. I want the additions to the SVG for the benefit of blind users to be created without human intervention. In concept this is already possible. In practice, there is a lot of work to do to make it a reality.

With respect to alternative braille fonts, I have no idea how hard it would be to incorporate a tool that would convert to contracted braille, and then also have to worry that this is really only of practical use to the British, North Americans, Nigerians, kiwis, Aussies, and South Africans.  I’ll suffer through uncontracted braille for a long time before investing much energy into the contraction process.
With respect to putting Nemeth code on plots for the mathematical material, I would remind people that this code is not well-known everywhere as it was never used as the official braille mathematics code in so many countries in my list of English braille countries above.

I am really excited by developments in this arena be because it means we might find a way to offer braille producers a means of generating the braille versions of graphics being produced  using very manual processes at present.

Jonathan







From: BlindRUG [mailto:blindrug-bounces at nfbnet.org] On Behalf Of JOOYOUNG SEO via BlindRUG
Sent: Friday, 12 June 2015 10:54 a.m.
To: 'Blind R Users Group'
Cc: JOOYOUNG SEO
Subject: [BlindRUG] Sharing Successful Braille Labelling Test

  Hello Dr. Godfrey,
  I am writing to share my test with you.
  Today, I worked with my colleague to use braille font in R graphics and it was successful and an eye-opener.
  I hope our findings could contribute to updating future BrailleR.

  1. I downloaded this font<http://www.fontspace.com/philing/braille-normal> and installed it.
  2. The following is the syntax I used to get the braille-labled histogram:

chooseCRANmirror(ind=1)

install.packages("extrafont")

library(extrafont)

data(airquality)

attach(airquality)

font_import(pattern="BRAILLE1.ttf", prompt=FALSE)
windowsFonts(A=windowsFont("Braille Normal"))

hist(Ozone, family="A")
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  3. Problem and question:
  A. I cannot save the graphic as PDF.
  B. Do you think we can also get free grade2 braille font? This is grade1.
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  Thank you.
  Best Regards,
       JooYoung
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