Colored Nonograms: An Integer Linear Programming Approach

In this paper we study colored nonogram solving using Integer Linear Programming. Our approach generalizes the one used by Robert A. Bosch which was developed for black and white nonograms only, thus providing a universal solution for solving nonograms using ILP. Additionally we apply a known algorithm to find all solutions to a puzzle. This algorithm uses a binary cut to exclude already known solutions. Finally we compare the performance of our approach in solving colored nonograms against other approaches, namely the iterative and the brute-force ones, pointing to a research direction of developing a hybrid method combining the iterative approach with ILP.