[Coco] Initial Tests and Results

Michael Wayne Harwood michael at musicheadproductions.org
Sat Jun 11 13:17:05 EDT 2005

Misprint!!  "If you look over the grfx_all.txt file" in the File Sizes
section should read "If you look over the sizes.txt file".


Michael Harwood

> I have been gathering data to use in determining what standards should be
> set for several aspects of the Rainbow on Disc project.  There are two
> distinct aspects I was seeking to gather data for: 1) appropriate
> standards for the orginal scans of the magazines, and 2) end product post
> production issues.  This email is meant to be a quick summary of the work
> done so far - I apologize for the somewhat haphazzard way this is
> presented - this information is provided as a starting point for
> discussion.
> Files on the Web
> ----------------
> I have placed several .pdf files on my website for reference.  The largest
> of them is 2.8mb in size, but please bear in mind that my web server is on
> the other end of a consumer DSL connection.  My uplink is rated for a
> maximum speed of 384kbps, so if multiple people are downloading things it
> may be a bit slow.  The following is a list of the files that are
> pertinent to this post:
> A summary of file sizes.
> http://www.musicheadproductions.org/coco/sizes.txt
> PDF files that summarize the tests.  150ppi.pdf, 200ppi.pdf, and
> 300ppi.pdf all have three pages each - the first page is a scan at 1bit
> black and white, the second page is a 24bit color scan, and the third page
> is the result of post processing (see the section below regarding this).
> The grfx_all.pdf file is to show the results of what a scan of a page with
> full color graphics would look like at different scan resolutions.
> grfx_all.pdf has three pages - page 1 is a 150ppi scan, page 2 is a 200ppi
> scan, and page three is a 300ppi scan.
> http://www.musicheadproductions.org/coco/150ppi.pdf
> http://www.musicheadproductions.org/coco/200ppi.pdf
> http://www.musicheadproductions.org/coco/300ppi.pdf
> http://www.musicheadproductions.org/coco/grfx_all.pdf
> File Sizes
> ----------
> If you look over the grfx_all.txt file you can see a summary of the file
> sizes I came up with throughout all of the steps.  I feel the results
> documented are fairly self explanatory, but if for some reason I have left
> out information that would make things clearer please let me know.
> Post Processing
> ---------------
> To get the result from page 3 of the example .pdf files (300ppi.pdf, etc)
> I used two scans of the same page (24bit color and 1bit B&W) so that I
> could use the 1bit black and white scan to create a mask applied to the
> 24bit color scan so that only the color information I wanted to show would
> come through.  The end product looks quite a bit cleaner that the orginal
> 24bit color scan, though there is a little loss in graphic quality.
> Here are the steps I used:
> 1. Load the 24bit color scan into the Gimp
> 2. Load the 1bit B&W scan as a second layer on top of the color layer 3.
> Use the "Select a color" tool to select all the black areas in the B&W
> layer.
> 4. Clear all of the selected black areas in the B&W layer to make these
> areas transparent - the bottom color layer should now show through the
> areas cleared.
> 5. Merge the layers
> 6. Save the result
> Regards,
> Michael Harwood
> /Any spelling errors are intenshunal/
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco

"The best place to be is here,
 the best time to be is now."
             -- Bill and Ted

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