“…The mechanism used for database image indexing is depicted in details in Korytkowski et al (2016) and Korytkowski (2017). Usually, classifiers are used for the purposes they are intended (Hoang, 2017;Pham, Nguyen, Tran, Nguyen, & Ha, 2017), but in the paper, we use weak classifiers to obtain distinctive features for a given visual class. Currently, deep learning-based approaches (Bologna & Hayashi, 2017;Chang, Constante, Gordon, & Singana, 2017) are gaining popularity in image analysis, but they are slower than the proposed approach and not suitable for relational database purposes.…”