[Blindmath] Extracting bitmap images from pdf files

[Michael Whapples]

John,
In some PDF diagrams, normally graphs and such like, the text labels may 
actually be there as text (I could send some examples if you need). In such 
a case will IVEO actually use the text rather than relying on OCR?

Michael Whapples

-----Original Message----- 
From: John Gardner
Sent: Wednesday, January 25, 2012 6:33 PM
To: 'Blind Math list for those interested in mathematics' ; 
accessibleimage at freelists.org
Subject: Re: [Blindmath] Extracting bitmap images from pdf files

Dick, if someone is fortunate enough to have a ViewPlus embosser and IVEO
Creator Pro, she can have pretty good access to images.
* import the PDF into IVEO Creator Pro.
* Check the PDF to find which pages have images of interest and emboss those
pages.
* Put the embossed page on the touchpad and "Zoom Rectangle" by clicking on
diagonally-opposite corners of the image of interest.  This will zoom that
image to occupy maximum size the page will permit.
* Emboss the zoomed image and read it using the touchpad.  Horizontal text
on the image should read when pressed.  The OCR in Creator Pro works really
well with PDF's so if the resolution is at all decent, the text usually is
OCRed well.
* Go back to the original image and do same for any other image on that
page.  Repeat for images on other pages.

Note that a sighted person can skip the first embossing step and just zoom
those images.  Handy to have sighted people around, but if there aren't it
just takes a little longer.  By the way, that sighted person can create
overlays on important objects on the graphic and label them to improve
accessibility even more.

John

-----Original Message-----
From: blindmath-bounces at nfbnet.org [mailto:blindmath-bounces at nfbnet.org] On
Behalf Of Richard Baldwin
Sent: Wednesday, January 25, 2012 10:08 AM
To: BlindMath Mailing List; accessibleimage at freelists.org
Subject: [Blindmath] Extracting bitmap images from pdf files

Many blind students receive electronic textbooks in pdf format.

Many textbooks contain lots of images.

Many images are poorly described in textbooks.

Various ways to convert bitmap images into tactile images are available --
some fairly good, some not so good, some very poor. However, regardless of
the quality of the conversion to tactile format, you must have the original
image file in order to get anything.

I have tried four or five different online file conversion sites in an
attempt to find a clean way that a blind student can extract the images
from a pdf textbook file without success. Different sites have different
problems, but they all seem to have some kind of problems that make it very
difficult to extract the images from pdf files.

Has anyone identified an online site or downloadable program that is
available either free or at a reasonable price to cleanly extract the
images from pdf files, which often range up to 10 or more megabytes  or
more in size?

Thanks,
Dick Baldwin

-- 
Richard G. Baldwin (Dick Baldwin)
Home of Baldwin's on-line Java Tutorials
http://www.DickBaldwin.com

Professor of Computer Information Technology
Austin Community College
(512) 223-4758
mailto:Baldwin at DickBaldwin.com
http://www.austincc.edu/baldwin/
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