Book People Archive

Re: slipper point mystery 

Nick Hodson wrote:
> I think JMO's postulation that this compression might have something to do
> with JPG2000 might well be correct, but I am not sure. There are some 
> hints
> thrown out on http://www.luratech.com/  . The reason I'm not sure is 
> because
> I compress my bitonal scans with Group4 and don't get anywhere near the
> compression that Google gets.

Google is using JBIG2 compression for the public domain PDF files offered:
http://en.wikipedia.org/wiki/Jbig2
The files I've looked at also have several color page images of print-only 
pages that are of lesser quality.  These may be there due to poor quality 
control or perhaps to make it more difficult to repackage the content. The 
color files seem to be from standard JPEG or JPEG2000 set to a very low 
quality level.

> At 9/1/2006 10:06:17 PM Bowerbird wrote:
>
>> the image pages should be scanned too.
>> they don't have to be done at a higher resolution,
>> because that's not the primary objective
>
> If, as a layman to this whole issue, I may add a word, I'd agree in most
> cases, but especially for historical and scientific work, ability to read
> images well (even marginal quality lithographs) can be highly important.
> To take one example, for archaeological scholars, ability to *clearly*
> read reproductions of e.g. cunieform, heiroglyphs, and artifacts can be
> of great value.  Admittedly, such books may be a minor proportion of the
> total being archived, but then we enter the question of the relative
> cultural significance of  such work compared to most fiction.

A pertinent example (right down to the cuneiform) of the importance of high 
quality image availability is:
http://fax.libs.uga.edu/DS71xJ39C/
The most efficient method of viewing this work is to browse it from the 
server with the DjVu plug-in as the page images are discrete and only 
download as the user requests them.  This book can also be downloaded as a 
single PDF or more heavily compressed DjVu file here:
http://fax.libs.uga.edu/DS71xJ39C/1f/
There is also an uncorrected OCR text file as well as the high quality (HQ) 
DjVu version that is a bundled version of what is directly served via the 
DjVu plug-in.

This book: The civilization of Babylonia and Assyria; its remains, language, 
history, religion, commerce, law, art, and literature, by Morris Jastrow, 
Jr. ... with map and 164 illustrations (1915), was scanned with a $250 
OpticBook scanner.  I have devised a simple method to make book scanning on 
the OpticBook much easier. It basically involves creating a stable way to 
tilt the front of the scanner up by around thirty degrees so the weight of a 
book is better distributed. This tilt also reduces the problem of paper 
fragments or dust, as these particles will tend to slide away from the 
scanning area rather than needing to be brushed away between scans as is 
often the case with a standard flatbed scanner. Though there are several 
ways to do this physically, commonly available metal bookends work quite 
well and are likely to readily available to most users of the OpticBook. The 
bookends also serve as an edge stop so the front of the OpticBook actually 
extends beyond the edge of the desk or table it is being used on; this makes 
it much easier to press a book against the scanner from its spine and also 
provides clearance for the part of a book that is hanging down. I've done 
well over five thousand scans with the machine tilted in this fashion and it 
continues to work fine.

You can view images of the arrangement here:
http://fax.libs.uga.edu/zlog/opticbook/

bobk

Bob Kobres

Hargrett Library
University of Georgia
Athens, GA 30602

http://abob.libs.uga.edu/bobk
http://fax.libs.uga.edu