subliminal color images

[Benjamin C. Wiley Sittler]

forgot the link:

http://en.wikipedia.org/wiki/Tincture_(heraldry)

here's a quick and approximate mapping in ASCII-art:

	rgb	en-US	xno	ASCII
	===	=====	=====	=====
	···	black	sable	"##"
                                "##"
	··1	blue	bleu	(see azure ·½1)

	·½1	azure	azure	"=="
				"=="
	·1·	green	vert	"\\"
				"\\"
	·11	cyan	bleu	(see azure ·½1)
			celeste

	½½½	grey	cendrée	"-|"
				"|-"
	1··	red	gules/	"||"
			sinople	"||"
	1½·	orange		(see red 1··)

	1·1	purple	purpure	"//"
				"//"
	11·	yellow	or	"::"
				"::"
	111	white	argent	"  "
				"  "

in rgb triples · = 0%, ½ = 50%, and 1 = 100%

NOTE: blue ··1 cyan ·11 are not distinguished from from azure ·½1

NOTE: orange 1½· is not distinguished from red 1··

NOTE: xno is ISO 639-3 for "Anglo-Norman"

On Mon, 2006-10-16 at 13:07 -0700, Benjamin C. Wiley Sittler wrote:
> why not support the classic engraving marks? that way cellphone + old
> book/reproduction = color engraving.
> 
> On Mon, 2006-10-16 at 14:40 -0400, Kragen Javier Sitaker wrote:
> > On Mon, 16 Oct 2006 12:17:50 +0200, Dave Long wrote:
> > > > It would be cool to print out a black-and-white image on, say, a laser
> > > > printer, which contained an unobtrusive embedded "watermark" or
> > > > "barcode" that contained chroma information for the image --- rather
> > > > like what the Apple II did to get NTSC color just by producing a
> > > > pattern of 1's and 0's.
> > > 
> > > Come to think of it, the Apple II scheme turns a well known broadcast 
> > > bug (there are dress codes for on-air appearances, as houndstooth and 
> > > similar high-frequency fabrics alias into color) into a feature.  I 
> > > wonder how much the use of gradients in web graphics is due to 
> > > recent-featurism, and how much is in imitation of broadcast graphics, 
> > > which have to have smooth gradients -- they'd bleed if one tried to 
> > > make a crisp transition.
> > 
> > That's an interesting question.  My preferred hypothesis is that it's
> > the age of calm technology --- one of the disadvantages of the Apple
> > ][ scheme was that it could only produce bright, garish colors with
> > sharp boundaries between them, and gradients are much more soothing.
> > 
> > > > Then you could point, say, a cellphone camera at the image, and push a
> > > > button, and see the image in color.
> > > 
> > > Unfortunately (fortunately?) the information between a cellphone camera 
> > > and a printout isn't mediated by NTSC, but by regular photons, so it 
> > > seems unlikely this would work.
> > 
> > I didn't mean it would work by accident --- I meant that software in
> > the cellphone could decode a chroma signal from a barcode "hidden" in
> > the image, for example in the angle and spacing of patterns of
> > parallel lines used to approximate a grayscale as in an engraving.
> > 
> > Venezuelan paper money has areas that appear from a distance to be one
> > solid color, but consist of many areas of fine parallel lines at
> > different angles.  Presumably the idea is that each area would appear
> > a different brightness by raster aliasing if scanned with a
> > poor-quality scanner, or printed with a poor-quality printer.
> > 
> > But the same scheme could be applied to encode more interesting
> > information subliminally into the print; perhaps the frequency of the
> > lines could represent saturation, and their angle could represent hue.
> > 
> >