# GazeGuide: An Eye-Gaze-Guided Active Immersive UAV Camera
## 2 Related Works
### Gaze-Based Interaction and Control  
As part of the development of interactive applications, many researchers have used the eye-gaze as an input to achieve user interface-based HCIs. The introduction of several fundamental gaze-based techniques by [PERSON] [20] showed the usage of eye movements as a fast input mode for interaction. In another study, a gaze-based interface was proposed by [PERSON] et al. [38; 39] to teleoperate a robot by aiming at minimizing the human body engagement of the operator in the controlling task. A human eye-gaze-based interface was used to control a wheelchair in [40] and similarly, in [41], a recent study with a case study was reported. [PERSON] et al. [42] presented a novel gaze-based interface called GazeTorch, comparing between the use of gaze and that of mouse pointers in remote collaborative physical tasks [43]. A study [44] showed the benefits of gaze augmentation in egocentric videos in a driving task. [PERSON] et al. [45] proposed the teleoperation of a robotic arm from a remote location by using an experimental eye-tracking algorithm. Furthermore, [PERSON] et al. [46] presented a telerobotic platform using the eye as the input to control the navigation of a teleoperated mobile robot. The demo explored the use of gaze as an input for locomotion. In [47], the researchers presented an experimental investigation of gaze-based control modes for UAV, and in [48], the scholars investigated a gaze-controlled remote vehicle while driving it on a racing track with five different input devices. \begin{table}
\begin{tabular}{l l c l} \hline
**Eye-Movement Type** & **Definition** & **Occurrence Duration** & **Significance** \\ \hline Fixation & Maintaining visual gaze on a single location & 200–400 ms & Acquiring information, Cognitive processing \\ Saccode & Simultaneous eye movements between fixations & 20–200 ms & Moving between targets \\ Smooth Pursuit & Eyes closely following a moving object & 100 ms & Following moving targets \\ Scan path & Series of fixations and saccades & - & Scanning, direct search \\ Gaze duration & Total fixation time on a target & - & Cognitive processing and conveying intent \\ Blank & Rapid eyelid closing & 300 ms & Indicates behavioral states, stress \\ Pupil size change & Pupil constriction or dilation & 140 ms & Cognitive effort, representing microemotions \\ \hline \end{tabular}
\end{table} 
Table 1: Eye-movement classification. Figure 1: Number of peer-reviewed articles over the past 55 years with the phrase eye tracking and/or eye movements (ProQuest databases). On a similar line of thought, [PERSON] et al [49] presented GazeDrone, a novel gaze-based interaction in public pervasive settings, and [PERSON] et al. [50] used gaze gestures as an object selection strategy into HRI to teleoperate the drone. [PERSON] et al. [51] explored eye tracking for surgical applications by using simultaneous displays of two users' gaze points to indicate their respective intents during robotic surgery tasks. In a study [52], gaze information obtained by an eye tracker could be used to create a gaze-contingent control system to move the camera; with this, it became possible to move the camera by following the user's gaze position on the target anatomy. In a recent survey [53], the authors explored gaze-based interactions in the cockpit, which actively involved the pilots in the exploration. Furthermore, in the survey report [10], [PERSON] et al. [54] outlined earlier work that used the eye-gaze and explained the high-level outcomes achieved from an application-oriented perspective through the eye-gaze in HRI. [PERSON] et al. [19] summarized the compelling reasons, advantages, and motivations for gaze-based controls as follows:  
* Gaze can be an effective solution for situations that prohibit the use of hands. * Velocity is another important feature of gaze control, because an object can be looked at considerably faster than it can be reached by hand or any tool. Hence, the use of the eye-gaze increases the speed of the user input.