Yet another sudoku solver based on Knuth's dancing link algorithm. And a sudoku grabber using OpenCV, i use a lot of ideas from stackoverflow, several blogs in order to build this in java, so many thanks to all people that work hard to transfer knowledge.

Dancing package is the implementation of the dancing links algorithm and the sudoku-problem model. If you give a Board to this you are ready to go.

This is more like a work-in-progress, theres several ideas out there, it work with a few images, and fails miserably with others. If you want it to run, you need a compiled binary of OpenCV i'm using now 2.4.8, and the jar. Put the sharedlibraty on lib/, install opencv jar with maven and the exec:exec do the rest.

Install in a local maven repo opencv-jar

 mvn install:install-file -Dfile=lib/opencv-248.jar
                          -DgroupId=org.opencv
                          -DartifactId=opencv
                          -Dversion=2.4.8
                          -Dpackaging=jar
                          -DgeneratePom=true
                          -DcreateChecksum=true

For the shared library, just copy into the lib/ exec:exec will try to look there, or just set java.library.path.

Compile it! :-)

mvn compile

And... probably it will run! (java binary should be in path)

mvn exec:exec -Dimage=src/test/resources/sudoku_ok_2.jpg

This is the input:

and the Output is:

Grabbed sudoku
==============


3 4 0  0 0 8  0 0 0
0 0 7  0 0 1  8 0 0
0 8 9  5 0 0  4 2 0

0 0 6  0 0 0  9 0 3
0 2 0  0 0 0  0 8 0
4 0 8  0 0 0  2 0 0

0 1 2  0 0 7  6 4 0
0 0 5  8 0 0  7 0 0
0 0 0  1 0 0  0 9 8


Solved sudoku
=============


3 4 1  6 2 8  5 7 9
2 5 7  4 9 1  8 3 6
6 8 9  5 7 3  4 2 1

1 7 6  2 8 4  9 5 3
5 2 3  7 6 9  1 8 4
4 9 8  3 1 5  2 6 7

8 1 2  9 3 7  6 4 5
9 3 5  8 4 6  7 1 2
7 6 4  1 5 2  3 9 8

and in the begging you will see some debug information:

[3, 3, 3]
[4, 1, 4]
[8, 8, 8]
[7, 7, 7]
...
[1, 1, 1]
[9, 9, 9]
[8, 8, 8]

That's the result to apply to the detected digits KNN with k=3. Also it will generate a file called cells_boxed.jpg witch contains each cell of the sudoku and a boundbox for the digit.

• José Luis Diaz (diazjoseluis at gmail dot com)

Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0