Fundamental region based indexing and classification of Islamic star pattern images

In this paper, we propose a new method for the indexing and classification of Islamic Stars Pattern (ISP) images based on rotational symmetry information. A computational model for the extraction of rotational symmetry features is proposed. This model is based on the three following steps. First, we detect the rotation center of the ISP image, then we complete the image structure by using symmetry information. Second, we compute the angle of rotation and number of folds. Finally, we extract the fundamental region, a representative region in the image from which the whole image can be regenerated. A method is also proposed for indexing and classifying ISP images on the basis of the extracted features. The classification algorithm is based on the number of folds. We characterize an image by its fundamental region and by its class which is defined in the classification step. Experiments show promising results either for ISP images classification or indexing. Efforts for the subsequent task of repeated pattern images classification can be significantly reduced.