Baeza-Yates, R. and IM. Rignier, Fast two-dimensional pattern matching, Information Processing Letters 45 (1993) 51-57. An algorithm for searching for a two-dimensional m X m pattern in a two-dimensional n x II text is presented. It performs on the average less comparisons than the size of the text: n’/m using ma e.xtra space. Basically, it uses multiple string matching on only n/m rows of the text. It runs in at most 2nz time and is close to the optimal n’ time for many patterns. It steadily extends to an alphabet-independent algorithm with a similar worst case. Experimental results are included for a practical version.