Exploring the capabilities of portable device photogrammetry for 3D surface roughness evaluation

Figures & data

Figure 1. Point cloud of original (a) smooth, (b) intermediate, (c) rough surfaces. Different colours represent the surface elevations; blue is the lowest location, and red is the highest part of the surface.

Figure 2. (a) Smooth, (b) intermediate, (c) rough surface specimens.

Figure 3. Setup of (a) structured light 3D scanner, (b) iPhone 12 Pro Max, (c) terrestrial LiDAR scanner.

Table 1. The specifications of the structured light 3D scanner.

Scanning parameters	Specifications
Scan accuracy	.04 mm (single shot)
Scan speed	Single scan < 1s
Point distance	.16 mm
Single scan range	150 × 120 mm − 250 × 200 mm
Depth of field	100 mm
Working distance	400 mm
Light source	LED

Figure 4. Profiles selected on the smooth surface with a sampling interval of 0.1 mm, (a) X direction, (b) Y direction, (c) different directions were selected at the interval of 15°.

Figure 5. The reconstructed 3D surfaces from (a) structured light 3D scanner, (b) portable device photogrammetry, (c) terrestrial LiDAR scanner.

Table 2. Information of reconstructed 3D surface models.

Scanning Method	Surface Roughness	Size			Number of Points	Average Point Density (points/mm^2)
		X (mm)	Y (mm)	Z (mm)
Structured light 3D scanner	Smooth	95.8	98.5	6.7	198,553	21
	Intermediate	97.9	98.3	9.2	193,919	20
	Rough	96.5	98.3	15.2	205,183	21
Portable device photogrammetry	Smooth	96.4	99.7	6.8	372,694	38
	Intermediate	100.3	100.4	10.4	508,993	50
	Rough	96.3	99.5	14.8	474,086	49
Terrestrial LiDAR scanner	Smooth	96.2	100.1	8.2	28,454	3
	Intermediate	6.0	94.4	12.7	24,251	3
	Rough	97.0	96.3	18.3	25,722	3

Figure 6. The distance distribution from generated grid points to the interpolated (a) smooth, (b) intermediate, (c) rough surface (relative height).

Figure 7. Distribution and occurrence of the cloud-to-cloud distance of the point clouds, (a) smooth, (b) intermediate, (c) rough surface.

Table 3. The cloud-to-cloud distance between the structured light 3D scanner model and the portable device photogrammetry model.

	Mean (mm)	Standard deviation (mm)	RMSE (mm)
Smooth	0.30	0.59	0.66
Intermediate	0.32	0.72	0.79
Rough	−0.34	0.51	0.62

Figure 8. Comparison of the line profiles from the structured light 3D scanner and portable device photogrammetry images at the surface centre along the X-axis. a smooth, b intermediate, and c rough surface.

Figure 9. Anisotropic distribution of average JRC values for (a) smooth, (b) intermediate, and (c) rough surface.

Table 4. Comparison of JRC values for different surfaces.

Surface	Direction	Structured light 3D scanner		Portable device photogrammetry	ErrorJRC	Back-calculated JRC
Smooth	X		9.50	9.33	−1.79%
	Y		8.82	8.66	−1.81%	9.58
	Anisotropy		9.71	9.77	0.62%
Intermediate	X		10.78	11.12	3.15%
	Y		11.73	11.48	−2.19%	11.10
	Anisotropy		11.83	12.10	2.28%
Rough	X		17.43	16.40	−5.92%
	Y		12.39	11.97	−3.42%	\
	Anisotropy		17.66	16.90	−4.31%

Figure 10. Distribution of 3D roughness parameter for a smooth, b intermediate, and c rough surface.

Table 5. Comparison of 3D roughness parameter $\frac{{\theta }_{max}^{\ast }}{C+1}$.

Surface	Structured light 3D scanner	Portable device photogrammetry	$Erro{r}_{\frac{{\theta }_{max}^{\ast }}{C+1}}$
Smooth	8.51	8.50	−0.12%
Intermediate	9.66	9.90	2.48%
Rough	12.53	12.05	−3.83%