Tomislav Petkovic Davor Petrinovic Sven Loncaric 12th International Symposium on Image and Signal Processing and Analysis, ISPA 2021, Zagreb, Croatia, September 13-15, 2021 ISPA IEEE 2021 978-1-6654-2639-8 https://doi.org/10.1109/ISPA52656.2021 db/conf/imspa/ispa2021.html