[Coco] Scan Test

John R. Hogerhuis jhoger at pobox.com
Thu Jun 9 01:41:38 EDT 2005

On Wed, 2005-06-08 at 22:52 -0600, Michael Wayne Harwood wrote:
> Hey all - do me a favor and take a look see at the following --> 
> http://www.musicheadproductions.org/coco/softside_test.pdf.  I did some
> quick guess based calculations and came up with the preliminary conclusion
> that if we produced .pdfs of this quality we should be able to fit the
> entire collection of Rainbow on somewhere around 7 or 8 DVD's...  My
> numbers are based on guesses and most likely not conservative, but it's a
> place to start.

I cancelled the download, it was estimating a half hour.

I think these are way too big. we'll have logistical issues just getting
stuff from one person to another.

Have you tried zipping the pdf?

> The scans were done at 300ppi with a color depth of 24bits, and then
> converted to a 144ppi pdf.  I think the scan quality is acceptible, though
> there is quite a bit of post scan cleanup that could be done to spiff the
> images up.

Do we really need 24-bit color depth? IIRC the magazine itself was
pretty much black and white with the occasional halftone as an accent. I
think the only color stuff that really deserves special attention are
the covers. We could make exceptions here and there where it makes sense
of course.

It may be we could just lower the bit depth and without much risk. 4 or
8 bit color is probably enough for most of the mag, even if we decide to
go for color.

I understand everyone wants something pristine, but it is probably wise
to accept some compromises for tractibility/logistical reasons.

> I think OCR might be a separate project considering space requirements. 
> The orginal 300ppi tiff files that were used to generate this pdf were
> almost 250mb for 12 images.  I don't think it's very feasible to consider
> selling the high resolution masters to everyone - the media costs and time
> to burn that many DVDs would be prohibitive.

I agree. But it would be good if hi-res archive were available for no
more than the additional expense of media, burning them and shipping

I think it would be wise to work backward from the size of 1 DVD and see
what can be fit there if we try to cram it all in. I think 

Alternatively the dvds could be divided into volumes per-year. This
would relieve some of the size contraint. This might be helpful to
people who already have entire years worth of mags and just want to fill
in the gaps. But this adds some complexity and cost.

>   In my experience OCR works
> much better with 2bit (black and white) images than grayscale or color.

This need not affect any decisions... ImageMagick (a free tool) can
down-convert color->greyscale or b&w at a batch level.

-- John.

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