April 28, 2012

Notes on these compact scans of Workers Monthly:

My scanning technique evolved as this project was in progress.

There was the goal of making reasonably decent, compact scans that could be relatively easily emailed and downloaded with existing technology (bandwidth) of 2012 and the likely near future, and the goal of providing some high quality archiving of cover and interior art.  

I was not able to achieve both in a single scan of the magazine.

(1) Compact "distribution" scans to preserve content and provide a reasonable representation of the art:

The "distribution" scans made for content are nearly all under 8 megabytes in file size.  They consist of one 24 bit 300 dpi color scan of the front and rear cover of the magazine (without color reference card provided, in part for reasons of space), and 24 scans of facing pages of the 48 page magazine using SINGLE BIT black and white scanning technique.  

At times I varied the technique, initially using a "text enhancement" feature of the Epson GT-20000 scan software, and later switching to manually controlled threashold (set to 80, mostly... sometimes 90) for other scans.  The results are similar, but there are minor pros and cons to one approach vs the other, and sometimes one approach better suits the art and photo content of one issue, and the other approach better suites the art and photo content of another issue.  Rendition of text and black and white block print and line drawing art is pretty much the same.  

Early on I experimented making 24 bit 300 dpi color scans of entire issues.  I did this with 4 issues, January 1926 thru April 1926.  Then decided this was too time consuming and unnecessary.  Those four "experimental" scans are provided in this archive.



(2) High resolution to preserve art:

THEN, to make this project provide high quality digital archiving of this important and famous publication, I went back and made sets of the following:

(1) 600 dpi high resolution 24 bit color scans of the covers, with a reference color card in the scan.  For these I used the slow, detailed scan mode of the Epson GT-20000.

(2) 300 dpi "quick" 24 bit color scans of the front and back covers, with a reference color card in the scan.


(3) 600 dpi "quick" 8 bit gray scale scans of all pages that had photos or art in every issue.   

(4) There are also some issues here for which I provide 600 dpi single bit BW scans.  THese represent an experiment on my part that later I rejected as redundant. 


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The compact scans of entire issues, all together, bulk about 250 megabytes in file size.

The high res scans, all together (24 bit color 600 dpi and 8 bit gray scale 600 dpi of selected pages that contain art or photos), bulk about 300 megabytes.


---marty

Martin H. Goodman MD 
Director, Riazanov Library digital archive projects