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Dense Scene Flow Estimation with the GVF Snake Model for Obstacle Detection Using a 3D Sensor in the Path-Planning Module Cover

Dense Scene Flow Estimation with the GVF Snake Model for Obstacle Detection Using a 3D Sensor in the Path-Planning Module

Open Access
|Nov 2023

Figures & Tables

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.

Figure 4:

Middlebury datasets: (a) Rubber Whale (b) Dimetrodon (c) Urban2.

Figure 5:

Error Plots for Middlebury Datasets (a) Rubberwhale Dataset (b) Dimetrodon Dataset (c) Urban2 Dataset.

Figure 6:

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)]

(μ = 0.01)(α = 0.01)AAESTDAEEPEAAESTDAEEPEAAESTDAEEPE
Lukas–Kanade0.31280.258950.5960.66910.36531.5350.88840.50218.000
Horn–Schunck0.31510.249850.6030.71410.36021.6250.96010.61288.038
LK–HS0.30590.26250.5860.66320.52021.6270.88730.70308.064
LK–HS–GVF0.30060.25850.5760.62910.30861.5260.87650.53817.870
Language: English
Submitted on: May 1, 2023
Published on: Nov 20, 2023
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2023 Sobers Francis, Sreenatha Anavatti, Mathew Garratt, Osama Hassan, Shabaan Ali, published by Macquarie University, Australia
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.