Retraction to: Multimedia Tools and Applications (2021) 80:34369–34387

https://doi.org/10.1007/s11042-021-11159-6

The Editor-in-Chief and the publisher have retracted this article. The article was submitted to be part of a guest-edited issue. An investigation by the publisher found a number of articles, including this one, with a number of concerns, including but not limited to compromised editorial handling and peer review process, inappropriate or irrelevant references or not being in scope of the journal or guest-edited issue. Based on the investigation’s findings the Editor-in-Chief therefore no longer has confidence in the results and conclusions of this article.

Byung-Man Kim disagree with this retraction. Jeong-** Youn, Su-Jeong Jeong and Kang-Hoon Lee have not responded to any correspondence from the editor/publisher about this retraction.