*4.2. MPIIGaze*

The MPIIGaze datasets were recorded using a laptop for several months over the daily lives of 15 experimental participants. The datasets were representative evaluations and very suitable for judging the performance of networks in uncontrolled settings. They were proposed in 2015 and include a head pose vector, gaze vector, full-face image, and 60 × 36 normalized image required for evaluations. The datasets also provide eye landmark co-ordinates of six eye edges and one iris center but do not provide enough for withindataset leave-one-person-out evaluations [11]. That is, the proposed network was trained using the data of 14 participants (3000 images consisting of left and right eyes) and then validated on the data of an excluded person. Thus, we made a labeling tool for rich eye landmarks as one is required by a neural network that is robust against noise.

Figure 9 illustrates an overview of this labeling tool. First, when a user draws a point on both endpoints of an eye, a line connecting the two points and straight lines dividing the line into eight equal parts are created. Subsequently, the remaining eye-edge co-ordinates are obtained by dotting the points at which the eight straight lines and eye region overlap. At this time, a correction effect is applied so that the drawn points lie on the straight lines. When a total of 16 eye edges are completed, the user specifies an elliptical area that can include the iris area. When eight dots are obtained, an ellipse is generated that best contains the iris through the RANSAC algorithm [37]. Users obtain 32 iris edges spaced at regular intervals from the ellipse. The datasets and code on 12 April 2022 are available to the public: https://github.com/OhJaeKwang/Eye\_Region\_Labeling.

**Figure 9.** From left to right presents the sequential labeling process. The red and green lines and blue dots are tools for landmark coordinates, and the red and yellow dots represent annotations. Outputs are comprised of 16 eye edges, 32 iris edges, 1 eye center, and 1 iris center.
