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Figure 1:
System Overview. (a) PMD camera mounted on P3DX. (b) Microsoft Kinect mounted on the AscTec pelican quadrotor. P3DX, Pioneer 3DX.
Figure 2:
Depth Camera Model.
Figure 3:
PMD Depth Image Analysis with Barrel Distortions. The distance between the PMD camera and the fixed board are: (a) 500 mm (b) 750 mm (c) 1000 mm (d) 1250 mm (e) 1500 mm (f) 1750 mm (g) 2000 mm (h) 2250 mm (i) 2500 mm.
Dense Scene flow in Various Directions (Bright Light); the Coordinate on the Bottom Left is the Camera Coordinate. (a) The x-flow and y-flow components are horizontal and vertical, respectively. To conduct this experiment, a 45º translation of the paperboard's x and y coordinates was made in the direction of the camera plane. (b) The z-flow component is horizontal, and the x-flow component is vertical. For this experiment, a combined motion in y and z coordinates was used to translate the paperboard in the direction of the camera plane. (c) The y-flow component is horizontal, and the z-flow component is vertical. To conduct this experiment, a combined motion in x and z coordinates was applied to the paperboard to translate it toward the camera plane.
Figure 7:
The Camera Coordinate Is in the Lower Left Corner of a Dense Scene Flow in Various Directions with Partial Light. (a) The x-flow and y-flow components are horizontal and vertical, respectively. The paperboard was moved toward the camera plane while conducting this experiment with a 45º motion in the x and y coordinates. (b) The horizontal component is z-flow and the vertical component is x-flow. Doing this experiment, the paperboard was translated toward the camera plane with a combined motion in y and z coordinates. (c) Z-flow is the horizontal component, and x-flow is the vertical component. For this experiment, a combined motion in y and z coordinates was used to translate the paperboard in the direction of the camera plane.
Figure 8:
Flow Vectors Are Shown with Close Objects Shown in Red and Far Objects Shown in Blue Using Various Methods. (a) Depth frame 1 with color coding. (b) Depth frame 2 with color coding. (c) Moving Obstacle Segmentation. (d) LK. (e) HS. (f) Combined Lk-HS. (g) Combined Lk-HS with GVF. GVF, gradient vector field; Lk-HS, Lucas–Kanade; Horn–Schunck.
Figure 9:
Experiment I: (a–c) Range Images with 200 × 200 Pixels; (d–f) Grayscale Images.
Figure 10:
Experiment I: 3D Renderings of PMD Camera on GLFW Window. (a) GLFW Frame 1.(b) GLFW Frame 2. (c) GLFW Frame 3.
Figure 11:
Different Frames of a Moving Obstacle. (A–J) Frame 1 to Frame 10.
Figure 12:
Obstacle Position in 3D Plot.
Figure 13:
Obstacle Segmentation: Dense Flow Vectors in 3D Plot.
Figure 14:
Experiment II: Path Planning with Two Irregular Shaped Obstacles. (A–E) Frame 1 to Frame 5.
Figure 15:
Experiment II: Real-Time Rendering of PMD Range Data Using GLFW. (a) Range intensity: Tripod (far). (b) Range intensity: Tripod (near). (c) Range intensity: P3DX(2) (far). (d) Range intensity: P3DX(2) (near). (e) 3D point cloud of obstacle: tripod. (f) 3D point cloud of obstacle: P3DX(2). (g) Experiment II: plot of AGV's X-coordinates vs Y-coordinates. P3DX, Pioneer 3DX.
Figure 16:
Experiment III on Moving Obstacle: 3D Renderings of PMD Camera.
Errors for Different Methods Compared with Middlebury Data Using MATLAB. [Regularization Parameter in GVF (μ = .01), Weighting Term (α = .01)]
