Invisible QR codes. | Bitcointalksearch.org

BitcoinPorn

hero member

Activity: 630

Merit: 500

Posts: 69

Quote from: ?? on ??

Cool idea but looks like marketing it will be tough.

Yes, seems like fun for creative people though. Finding ways to get people to scan a part of the page that shows nothing, which is good for actual conversions of qr scans. The bad part being them having to download an extra app to do it though.

HostFat

staff

Activity: 4270

Merit: 1209

I support freedom of choice

I like the idea of a "virus" that puts hidden QR-codes everywhere on images Grin

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

Quote from: idontknow on September 27, 2011, 06:04:10 AM

Can you show us the original SVG file for comparison or is it too big?

Nah, it's not "big" at all. I stripped just everything that looked like "extra" (namespace sodipodi and inkscape) or "default" (color:black), ids and some numbers precision. Probably adding back the first line would make the svg work in the browser:

Code:

xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:cc="http://creativecommons.org/ns#"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:svg="http://www.w3.org/2000/svg"
xmlns="http://www.w3.org/2000/svg"
xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
width="156.08125"
height="28.16"
id="svg2"
version="1.1"
inkscape:version="0.48.1 r9760"
sodipodi:docname="New document 1">
id="defs4" />
id="base"
pagecolor="#ffffff"
bordercolor="#666666"
borderopacity="1.0"
inkscape:pageopacity="0.0"
inkscape:pageshadow="2"
inkscape:zoom="0.35"
inkscape:cx="-267.49143"
inkscape:cy="-388.17143"
inkscape:document-units="px"
inkscape:current-layer="layer1"
showgrid="false"
fit-margin-top="0"
fit-margin-left="0"
fit-margin-right="0"
fit-margin-bottom="0"
inkscape:window-width="1112"
inkscape:window-height="740"
inkscape:window-x="134"
inkscape:window-y="155"
inkscape:window-maximized="0" />
id="metadata7">

rdf:about="">
image/svg+xml
rdf:resource="http://purl.org/dc/dcmitype/StillImage" />

inkscape:label="Layer 1"
inkscape:groupmode="layer"
id="layer1"
transform="translate(-121.06286,-116.03076)">
xml:space="preserve"
style="font-size:40px;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;line-height:125%;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;font-family:LMSans8;-inkscape-font-specification:LMSans8"
x="117.14286"
y="143.79076"
id="text2985"
sodipodi:linespacing="125%"> sodipodi:role="line"
id="tspan2987"
x="117.14286"
y="143.79076">Die Bibel

idontknow

newbie

Activity: 28

Merit: 0

Can you show us the original SVG file for comparison or is it too big?

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

Quote from: payb.tc on September 27, 2011, 05:49:41 AM

i'm looking at your SVG code now on my phone, thanks

I realized that it is maybe non-trivial to get the qr-code into an svg-file.

In order to get a rather small qr-code I stripped a lot of meta-data from the original svg-file as it came out of inkscape.
... uhm ... opening the file on my desktop works. In the browser it doesn't. Crippled too much, but you get the idea Wink

Here is the svg:

Code:

See?

payb.tc

hero member

Activity: 812

Merit: 1000

Quote from: giszmo on September 27, 2011, 05:46:27 AM

Well, svg is "text data". Am I missing something?

oh, i didn't know that.

(but i'm looking at your SVG code now on my phone, thanks)

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

Quote from: payb.tc on September 27, 2011, 05:08:38 AM

Quote from: giszmo on September 27, 2011, 04:36:59 AM

Quote from: Phinnaeus Gage on September 26, 2011, 06:52:51 PM

Quote

Storing a whole business card in a picture readable when offline would surely distort it much more.

How about a vector image?

I don't understand. The difference between vector and bitmap is only in the storage format. QR-like codes work even after printing when the storage format is "ink on paper".
Sure in an SVG you can embed arbitrary information. You can add a whole book without violating the SVG standard and without distorting the image's visual representation Wink

Check it out. It's 3.9MB and for convenience I put the bible as the title but other and new tags are perfectly allowed in the standard:

i thought bruno was saying "how about embedding a vector image into the photo, instead of embedding text data".

Well, svg is "text data". Am I missing something?

payb.tc

hero member

Activity: 812

Merit: 1000

Quote from: giszmo on September 27, 2011, 04:36:59 AM

Quote from: Phinnaeus Gage on September 26, 2011, 06:52:51 PM

Quote

Storing a whole business card in a picture readable when offline would surely distort it much more.

How about a vector image?

I don't understand. The difference between vector and bitmap is only in the storage format. QR-like codes work even after printing when the storage format is "ink on paper".
Sure in an SVG you can embed arbitrary information. You can add a whole book without violating the SVG standard and without distorting the image's visual representation Wink

Check it out. It's 3.9MB and for convenience I put the bible as the title but other and new tags are perfectly allowed in the standard:

i thought bruno was saying "how about embedding a vector image into the photo, instead of embedding text data".

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

Quote from: Phinnaeus Gage on September 26, 2011, 06:52:51 PM

Quote

Storing a whole business card in a picture readable when offline would surely distort it much more.

How about a vector image?

I don't understand. The difference between vector and bitmap is only in the storage format. QR-like codes work even after printing when the storage format is "ink on paper".
Sure in an SVG you can embed arbitrary information. You can add a whole book without violating the SVG standard and without distorting the image's visual representation Wink

Check it out. It's 3.9MB and for convenience I put the bible as the title but other and new tags are perfectly allowed in the standard:

phelix

legendary

Activity: 1708

Merit: 1020

Quote from: giszmo on September 26, 2011, 04:54:46 PM

For the fun of it:

[...]

and yes, even at this small scale the information can be extracted, so maybe it is slightly more sophisticated than what I suggested above Wink

+1, nice work, gisz!

Phinnaeus Gage

legendary

Activity: 1918

Merit: 1570

Bitcoin: An Idea Worth Spending

Quote

Storing a whole business card in a picture readable when offline would surely distort it much more.

How about a vector image?

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

Quote from: TiagoTiago on September 26, 2011, 05:59:14 PM

How long do you expect until people reverse engineer this and release a FLOSS variation of the standard?

Firstly, where is there a standard?

Secondly, I doubt it is hard to find out. Most likely if you ask them, they point you to the patent describing how it works. From their commercial though it is clear that all that is stored in the image is a little snippet of information - an ID maybe. The actual link behind that ID can be changed on the server at any time. This way it heavily relies on a central database with very limited information in the picture stored highly redundant. Storing a whole business card in a picture readable when offline would surely distort it much more.

TiagoTiago

hero member

Activity: 616

Merit: 500

Firstbits.com/1fg4i :)

How long do you expect until people reverse engineer this and release a FLOSS variation of the standard?

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

For the fun of it:

This car is also available without the embedded information:

+saturation
+lightness
*2
=

The image with the embedded information:

and yes, even at this small scale the information can be extracted, so maybe it is slightly more sophisticated than what I suggested above Wink

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

Ok, I tried the pdf and installed the android app and it's fun:

I stretched the saturation and brighness and cropped the image down to this little image:

Context:

And the app did still trigger. And no, it did not trigger when I pointed it to some other pictures, so I would assume the information to really be in the image.

giszmo

legendary

Activity: 1862

Merit: 1114

WalletScrutiny.com

Ok, i must take back my last post. This is interesting indeed.

My wild guess would be that they take a "QR-like code" and apply it to the image many times. Some areas get shifted to be green and some get shifted to be magenta. They do some kind of dithering with a set of patterns that all contain 50% green-shifting and 50% magenta-shifting. The ones can be translated to black and the others to white of the regular QR-code. As each such dithering pattern is balanced you don't see the QR-code without the appropriate pattern matching.

Now as a perceptible shift of the hue would be annoying in very bright and very dark areas, this is mainly done/visible in medium bright areas. Also highly saturated areas don't allow such operations without adverse effects.

casascius

vip

Activity: 1386

Merit: 1140

The Casascius 1oz 10BTC Silver Round (w/ Gold B)

Yep. Their technology reminds me more of Anoto digital ink (e.g. the "Tag" reader pen for kids) than a QR code. The dots are scattered all around the page, but more so in places where there's poor detail or no real color saturation, and I'll bet they're extremely redundant so only a small percentage of them is needed.

If you look at their sample PDF of a bright red car, there are no perceptible dots in the car itself... they are more in the background, in the sand, etc.

nhodges

sr. member

Activity: 322

Merit: 251

I don't get it, am I correct in the assumption it only scans with their proprietary scanning app?

casascius

vip

Activity: 1386

Merit: 1140

The Casascius 1oz 10BTC Silver Round (w/ Gold B)

I haven't read their spec, but when I blew their sample PDF up, it looked like it had a bunch of subtle imperfections in just one of the color planes (they were green and magenta) that could easily be what's encoding the data.

RodeoX

legendary

Activity: 3066

Merit: 1147

The revolution will be monetized!

I'm confused. Is this a photo with a stego QR image hidden in it, or is it scanning a known image?

Topic: Invisible QR codes. (Read 7244 times)