Ph.D. student Ing. Marek Šimka, in his dissertation titled “Image Quality in Multimedia Systems for Virtual Reality”, deals with the evaluation of visual quality of omnidirectional images compressed by emerging codecs. The thesis is structured into four main parts.

The first part examines the applicability of advanced image codecs, such as JPEG XL, HEIC, and AVIF, for compressing omnidirectional images, with performance assessed using conventional objective quality metrics. The second part introduces a new database, named OMNIQAD, which contains omnidirectional images compressed using codecs JPEG, JPEG XL, AVIF and HEIC. The database also includes eye-tracking data collected through a large-scale subjective quality assessment conducted in cooperation with university CTU. The third part forms the core of the dissertation and presents extensive cross-laboratory evaluations of image quality metrics applied to compressed omnidirectional images. These evaluations employ advanced statistical methodologies to ensure robustness and reliability of the provided study. In the fourth part, a new full-reference objective metric, named QFCOI, is proposed for assessing the visual quality of omnidirectional images compressed with advanced image compression algorithms. The objective metric was thoroughly validated using rigorous statistical procedures and benchmarked against several machine learning-based approaches. All relevant outputs of the thesis, including the OMNIQAD database and the source code of the proposed objective metric, have been made publicly available to the research community. The most significant scientific contributions are contained in the third and fourth parts of the thesis. The dissertation was written in English and was completed and submitted to the faculty’s scientific department at the end of the fourth year of full-time doctoral study.

Throughout his doctoral studies, Marek Šimka worked conscientiously and demonstrated a strong interest in his chosen research area. The main results of his dissertation were presented at four international conferences and published in two scientific journals. In addition, he is the author or co-author of seven further scientific publications in the field of mobile and wireless communications. According to the Web of Science database, his articles have received 34 citations (excluding self-citations). According to SCOPUS and Google Scholar databases, this number is 62 and 80, respectively. These results clearly confirm his ability to conduct independent scientific work and to contribute new knowledge to his field.

Ing. Marek Šimka also played an important role in several grant projects carried out by his supervisor and the Department of Radio Electronics. Moreover, he participated in teaching activities, particularly laboratory exercises in the course Television Technology and Multimedia, and he supervised two bachelor theses.

In my opinion, Ing. Marek Šimka has demonstrated all the necessary qualifications for independent scientific work, and he fully meets the requirements expected of a graduate doctoral program. I therefore highly recommend the submitted dissertation for defense.

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