“Aligning the background brightness of images of text characters using a high-pass filter” (2018) Bulletin of V.N. Karazin Kharkiv National University, series «Mathematical modeling. Information technology. Automated control systems», 37(1), pp. 5–19. Available at: https://periodicals.karazin.ua/mia/article/view/10512 (Accessed: 25 October 2026).