Info-Mac Archive Downloads: gst/grf/ Graphic

Back to gst/grf/ Graphic

os x'erox (open source for os x) (os-xerox.hqx)

Download os-xerox.hqx (1,268,148 KB)


From: "Paul M. Sheldon"
Subject: os x'erox (open source for os x)


This is the first draft of an ongoing project. It is open source.
It is spinoff from Mike Beam's column on cocoa programming.
I have a cannon elph powershot 200 2 megapixel digital camera which
I wanted to turn into a xerox machine for my research.

To inspire this (other than I want glory to get me credibility for
a post doc in quantum optics somewhere) :
Why pay xerox?
Why pay with filesize and lose hard drive space or burn too many cd's?
Why not hyperlink derivations for all books with adobe acrobat. I
have done this in journal publications in pdf format, but not with textbook
excerpts.

I only needed black and white and that reduces the filesize cost
from color by as much as 24 times. To this end, I've invented the notion of
"convolution thresholding", thresholding a sharpening convolution of the
digital camera image. This is something like the human eye does with
lateral inhibition, that is something like a digital Laplacian. Not quite.
I am subtracting out the background and thresholding to black and white.

These convolutions can be sped up with being modularized in FFT's,
fast fourier transforms. It would take about a semester to do, as I have
done, with butterfly diagrams guiding coding. Don't see anything in the
next step frameworks to assist development time, yet... When I or someone
else gets a FFT in it it will be one lean mean xerox copying machine.

Note, not exactly 24 times reduction as above because the .JPG file
you get out of a camera is compressed whereas the tiff you throw into a pdf
file is not, not at least as I understand how to do it. There is no JPG
compression for black and white. But, sometimes I can get costs of 16k, 32k
and 50k for page that started out as a 1Meg JPG and that's more than 24
times (I use other tricks, exporting from iPhoto by rescale when resolution
not required and cropping).