A picture maze is a maze on which some picture appears when a player successfully solves it.
This paper proposes an automatic generation method of such a maze.
Given a binary picture, the method extracts the contours and adjusts the structure of the contours to that of a maze path.
Then it connects all the contours to make one single cycle.
This cycle is actually the maze solution path which traverses all the contours of the original binary picture.
Accordingly, the picture will clearly appear on the maze when it is solved.
There are a number of aims in this paper.
First is to provide a clear explanation of the structure of an ordinary square grid maze;
second is to illustrate how contours of a binary picture
are organized as a graph;
third is to provide the intuitive and straightforward method to construct a picture maze by
converting the contours into one single contour;
fourth is to demonstrate that the maze can be complex to bury various
binary pictures or shapes such as letters, words, logos, pictograms and sentences, therefore be capable to transmit messages