We present QR_STENCILER, a free, fully-automated utility which converts QR codes into vector-based stencil patterns suitable for laser-cutting. Additionally, we present QR_HOBO_CODES, a series of one hundred QR stencil designs which, covertly marked in urban spaces, may be used to warn people about danger or clue them into good situations. The QR_STENCILER and the QR_HOBO_CODES join the Adjustable Pie Chart Stencil in our suite of homebrew "infoviz graffiti" tools for locative and situated information display.
CONTENTS
About this Project
Download & Instructions
License
The QR_HOBO_CODES
Acknowledgments
Keywords
ABOUT THIS PROJECTQR codes are a form of two-dimensional barcode which are widely used to convey URLs and other short texts through camera-based smartphones. A variety of free tools exist to generate QR codes (such as the Google Charts API) and to read them (such as TapMedia’s free QR Reader for iPhone app). Our QR_STENCILER is a Java-based software utility which loads a user-specified QR code image — from which it then generates a lasercutter-ready, topologically correct stencil .PDF. As Fred Trotter has pointed out, QR codes contain stencil islands in unpredictable configurations. QR_STENCILER automatically detects and bridges these islands, using thin lines that are minimally disruptive to the highly robust QR algorithm. It does so through the use of two basic image processing techniques: connected component labeling (sometimes called blob detection) and 8-connected chain coding (sometimes called contour tracing). QR_STENCILER was created with Processing, a free, cross-platform programming toolkit for the arts.
Closeup of a QR code lasercut in 1/8"-thick fiberboard. The QR_STENCILER automatically thickens corners between squares (left) and generates "bridges" to connect stencil islands (center). The level (amount) of island bridging is user-adjustable.
Accompanying the QR_STENCILER are the QR_HOBO_CODES (see below), a set of 100 lasercutter-ready QR stencil designs created with the QR_STENCILER software. These stencils can be understood as a covert markup scheme for urban spaces — providing directions, information, and warnings to digital nomads and other indigenterati. We present these as modern equivalents of the chalk-based "hobo signs" developed by 19th century vagabonds and migratory workers to cope with the difficulty of nomadic life. Indeed, our set of QR stencils port a number of classic hobo annotations to the QR format ("turn right here", "dangerous dog", "food for work") as well as some new ones specific to contemporary conditions ("insecure wifi", "hidden cameras", "vegans beware").
Examples of 19th- and 20th-Century "hobo signs". Sources: Fran DeLorenzo (left), Wikipedia (right).
DOWNLOAD & INSTRUCTIONSQR_STENCILER has been tested in MacOSX 10.6.8.
Download QR_STENCILER.zip, and unzip this to a folder.
Download and install the ‘Processing’ development tool. We used v.0198, but v.1.5.1 seems OK too.
Put your QR code image in the folder, ‘QR_STENCILER/data/’
Launch Processing and open ‘QR_STENCILER.pde’
Press ‘Run’ (Command-R) to start the stenciler.
You will be prompted to Open a QR code image. A default “hello world” QR code will be opened if none is provided.
After doing so, the program will generate a stencil .PDF in the ‘data’ folder.
The .PDF can be opened in your favorite CAD program, for laser-cutting materials like cardboard, MDF or acrylic.
We recommend Erwin Strait-Line 64908 powdered chalk ($1.39) for authentic hobo marks.
More photos: 1, 2, 3, 4, 5.
LICENSEThe QR_STENCILER software is provided "as is", without warranty of any kind. QR_STENCILER is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. You are free to distribute, remix, and modify QR_STENCILER, so long as you share alike and provide attribution to FFFFF.AT. The repackaging of QR_STENCILER as or into commercial software, is expressly prohibited. Please note that QR_STENCILER also enjoys protections under the GRL Repercussions 3.0 license. More details about QR_STENCILER’s license and warranty can be found in the preamble to its main code file, QR_STENCILER.pde; for other uses, please contact us. The 100 QR_HOBO_CODES and their respective stencils are hereby dedicated to the public domain.
QR_HOBO_CODES
25-minute waitpng | stencil
assholespng | stencil
bad coffeepng | stencil
bad foodpng | stencil
bad tempered ownerpng | stencil
bad waterpng | stencil
be alertpng | stencil
be quietpng | stencil
be ready to defend yourselfpng | stencil
beware pickpocketspng | stencil
bike thievespng | stencil
boringpng | stencil
broken meterpng | stencil
camera pervertspng | stencil
camp herepng | stencil
cars ticketedpng | stencil
caveat emptorpng | stencil
changing tablepng | stencil
cheap drinkspng | stencil
check cashingpng | stencil
civilized placepng | stencil
contraception availablepng | stencil
cops activepng | stencil
cops inactivepng | stencil
dangerpng | stencil
dangerous homophobespng | stencil
dangerous neighborhoodpng | stencil
dishonest scalpers herepng | stencil
dogpng | stencil
food for workpng | stencil
free doctorpng | stencil
free out-of-date foodpng | stencil
free wifipng | stencil
get out fastpng | stencil
go straightpng | stencil
good cheap foodpng | stencil
good coffeepng | stencil
good for a handoutpng | stencil
good to kidspng | stencil
good veg-burgerpng | stencil
good waterpng | stencil
GPS is incorrectpng | stencil
great dumpsterpng | stencil
habla espanolpng | stencil
has showerspng | stencil
help if sickpng | stencil
here is the placepng | stencil
hidden cameraspng | stencil
high-fee ATMpng | stencil
hold your tonguepng | stencil
insecure wifipng | stencil
it’s fakepng | stencil
just ignore himpng | stencil
keep awaypng | stencil
keep goingpng | stencil
kind familypng | stencil
lax oversightpng | stencil
look downpng | stencil
look uppng | stencil
lots of outletspng | stencil
mean to childrenpng | stencil
nice bathroompng | stencil
no bathroomspng | stencil
no changing tablepng | stencil
no fee ATMpng | stencil
no outletspng | stencil
no petspng | stencil
no privacypng | stencil
open latepng | stencil
over-pricedpng | stencil
over-ratedpng | stencil
owner gives to GOPpng | stencil
owner has a gunpng | stencil
pervertspng | stencil
pissoirpng | stencil
Plan B sold herepng | stencil
prostitution stingpng | stencil
scammerspng | stencil
sleep in barnpng | stencil
speed trappng | stencil
stay lowpng | stencil
strong phone signalpng | stencil
talk religionget foodpng | stencil
tell a hard luckstory herepng | stencil
test marketpng | stencil
those aren’t womenpng | stencil
toll roadpng | stencil
tramp camppng | stencil
tramps arrested on sightpng | stencil
turn left herepng | stencil
turn right herepng | stencil
unexpectedly good coffeepng | stencil
unsafe areapng | stencil
use glovespng | stencil
used frying oil availablepng | stencil
vegans bewarepng | stencil
well guardedpng | stencil
will give to getrid of youpng | stencil
work availablepng | stencil
worth savingpng | stencil
ACKNOWLEDGMENTSQR_STENCILER was created by Golan Levin and Asa Foster III with support from the STUDIO for Creative Inquiry at Carnegie Mellon University. Thanks to Ben Fry, Marcus Beausang, Neil Brown & Judy Robertson for the terrific code they have made available online. A tip of the hat to Fred Trotter, Jovino, le Suedois, Patrick Donnelly and others who have gone down similar paths. Additional thanks to Andrea Boykowycz for creative input. Some of the QR_HOBO_CODES are adapted from or inspired by designs presented elsewhere by Fran DeLorenzo and Cockeyed.com. "QR code" is trademarked by Denso Wave, Inc.
KEYWORDSQR code, stencil, QR code stencil, graffiti, grafitti, graffiti research, graf technology, street art, tactical media, urban messaging, locative media, situated visualization, contextual computing, lasercut, laser cutter, digital fabrication, template, chalk, spray paint, spraypaint, fffffat lab, hobo culture, hobo signs.
