Figure 7
The left panel labeled “(a)” shows an elevator entrance framed by metallic sliding doors that are partially open, exposing a light-colored interior wall and a closed gray door with a handle in the background. The door panels have visible vertical seams and reflective surfaces. Two thin vertical reference lines are overlaid near the left and right edges of the doorway, aligned with the door boundaries. On the left door panel, small circular safety icons are arranged vertically, and on the right side, a notice board and additional signage are visible on the wall next to the door frame. The elevator frame and surrounding panels appear smooth and metallic, with straight edges and a rectangular opening. The right panel labeled “(b)” contains a line graph with a legend labeled “Door position”, representing a line. The horizontal axis is labeled “time” and ranges from negative 2 to 16 in increments of 2 units. The vertical axis is labeled “Pixel value” and ranges from 300 to 600 in increments of 50 units. The plotted line begins near 320 around time 0, increases sharply around time 2 to reach 590 near time 4, remains nearly constant close to 590 until about time 10, then decreases rapidly after time 11 and returns to 320 by around time 13, remaining stable afterward. Note: All numerical data values are approximated.Video processing. (a) Edge position of the door. (b) Door displacement curve. Source(s): Figure created by authors