Tinytag
-------

Tinytag is a simple tag reader designed for embedded applications such
as mobile phones.  It is capable of reading high capacity square tags
at high framerate.  Tinytag is a barcode reader - it will read a
binary code from the tag but cannot provide 3D position or pose
information.  Users requiring 3D support should see the Cantag
project for more details.

* It is written in ANSI C and contains no floating point operations
(fixed point is used where required).

* Multiple tag sizes are supported (see the EDGE_CELLS parameters in
options.h)

* Use of CRC or simple checksum (see USE_CHECKSUM in options.h).  CRC
polynomial is selected automatically at compile time to be most
suitable for the chosen payload size


Compilation 
-----------

1) Edit the options for your tag design in options.h
2) Edit the Makefile if you wish to enable ImageMagick support for loading and saving images.  If you don't choose to use ImageMagick support then Tinytag is limited to using ascii, grey-scale PNM images.  Also check which targets you want to build - see the list of programs below.  Note that for Video4Linux you must hard code the image size in options.h for the camera that you are using.
3) Run make

Usage
-----

codegen - this program will generate an image of a tag and save it to disk.  The data to be coded should be given in hexadecimal:

	./codegen 0123456789ABCDEF output.pnm

imagetest - this program will load an image from disk, search for a tag and output the decoded tag data:

	./imagetest output.pnm

codetest - integrated test harness.  This program will generate a tag image in memory and then attempt to recognise it.  The decoded data are then compared to the input data to ensure no errors have occurred:

	./codetest 0123456789ABCDEF

v4ltest - Video4Linux test program.  This program will open the specified Video4Linux device (currently only cameras supporting YUV palettes devices are supported) and recognise images from it:

        ./v4ltest /dev/video0

Andrew Rice
acr31@cam.ac.uk