Line-Scan Camera Calibration Method Based on Absolute Phase Target

Fig. 2. Four-step phase-shifting fringe images of phase target with π/4 phase shift performed from left to right at each step. (a) Vertical fringe patterns; (b) slanted fringe patterns with Gray code

Download full size

Fig. 3. Restoring line-scan camera line of viewing using Gray coding in phase target

Download full size

Fig. 4. Obtaining rigid transformation matrix of target with aid of frame camera

Download full size

Fig. 5. Impacts of image noise on calibration parameters. (a) Absolute errors of $v_{0}$ and $f_{y}$ ; (b) absolute errors of translation vectors; (c) RMSE of reprojection

Download full size

Fig. 6. Effects of defocus on calibration parameters. (a) Absolute errors of $v_{0}$ and $f_{y}$ ; (b) absolute errors of translation vectors; (c) reprojection error

Download full size

Fig. 7. Impacts of distortion on calibration parameters. (a) Absolute error of $f_{y}$ ; (b) absolute error of $v_{0}$ ; (c) reprojection error

Download full size

Fig. 8. Calibration experiment. (a) Partial line-scan camera images used for calibration; (b) experimental setup

Download full size

Fig. 9. Spatial point distribution obtained by first calibration and corresponding positions of two cameras

Download full size

Table 1. Line-scan camera and frame camera parameters
View table
Table 1. Line-scan camera and frame camera parameters
Camera type Line-scan camera Frame camera
Sensor size 2048 pixel× 2 pixel 4096 pixel×3000 pixel
Pixel size 10.56 µm×10.56 µm 3.45 µm×3.45 µm
Lens focus 35 mm 12 mm

Table 2. Internal and external parameters of camera obtained by three calibrations

View table

Table 2. Internal and external parameters of camera obtained by three calibrations

Parameter	First calibration result		Second calibration result		Third calibration result
Parameter	Target with invariant cross-ratio	Phase target	Target with invariant cross-ratio	Phase target	Target with invariant cross-ratio	Phase target
$f$ /pixel	3615.06	3614.35	3614.08	3614.41	3610.45	3614.33
$v_{0}$ /pixel	1031.30	1029.62	1030.66	1029.78	1031.42	1029.55
$r_{1}$ /（°）	1.57	1.57	1.57	1.57	1.57	1.57
$r_{2}$ /（°）	0.68	0.16	0.14	0.15	0	0.15
$r_{3}$ /（°）	-0.02	-0.90	-0.02	-0.90	-0.01	-0.91
$t_{1}$ /mm	6.18	5.53	5.53	5.63	4.64	5.69
$t_{2}$ /mm	-105.76	-105.76	-105.78	-105.75	-105.72	-105.75
$t_{3}$ /mm	11.77	11.72	11.62	11.72	10.82	11.71

Table 3. Maximum residual and RMSE of reprojection for phase target and target with invariant cross-ratio

View table

Table 3. Maximum residual and RMSE of reprojection for phase target and target with invariant cross-ratio

Condition	Calibration method	Maximum residual error /pixel	RMSE /pixel
First calibration	Target with invariant cross-ratio	1.951	0.348
First calibration	Phase target	0.303	0.081
Second calibration	Target with invariant cross-ratio	1.891	0.465
Second calibration	Phase target	0.297	0.094
Third calibration	Target with invariant cross-ratio	2.366	0.496
Third calibration	Phase target	0.468	0.091
Mean	Target with invariant cross-ratio	2.069	0.436
Mean	Phase target	0.356	0.089

Tools

Get Citation

Copy Citation Text

Gan Huang, Shuangyun Shao, Jueting Luo. Line-Scan Camera Calibration Method Based on Absolute Phase Target[J]. Chinese Journal of Lasers, 2024, 51(2): 0204003

Download Citation

EndNote(RIS)BibTex Plain Text

Set citation alerts for article

Save article for my favorites

Paper Information

Category: Measurement and metrology

Received: May. 8, 2023

Accepted: Jun. 19, 2023

Published Online: Jan. 5, 2024

The Author Email: Shao Shuangyun (Shao_sy@tom.com)

DOI:10.3788/CJL230812

CSTR:32183.14.CJL230812

Topics

laser devices and laser physics

Lasers and Laser Optics

Laser physics

laser manufacturing

Instrumentation, Measurement and Metrology

Table 1. Line-scan camera and frame camera parameters

Table 1. Line-scan camera and frame camera parameters

Table 2. Internal and external parameters of camera obtained by three calibrations

Table 2. Internal and external parameters of camera obtained by three calibrations

Table 3. Maximum residual and RMSE of reprojection for phase target and target with invariant cross-ratio

Table 3. Maximum residual and RMSE of reprojection for phase target and target with invariant cross-ratio