| Literature DB >> 35401726 |
Jie Ren1, Fuyu Guan1, Tingting Wang2, Baoshan Qian3, Chunlin Luo1, Guoliang Cai4, Ce Kan1, Xiaofeng Li5.
Abstract
Camera calibration is the most important aspect of computer vision research. To address the issue of insufficient precision, therefore, a high precision calibration algorithm for binocular stereo vision camera using deep reinforcement learning is proposed. Firstly, a binocular stereo camera model is established. Camera calibration is mainly divided into internal and external parameter calibration. Secondly, the internal parameter calibration is completed by solving the antihidden point of the camera light center and the camera distortion value of the camera plane. The deep learning fitting value function is used based on the internal parameters. The target network is established to adjust the parameters of the value function, and the convergence of the value function is calculated to optimize reinforcement learning. The deep reinforcement learning fitting structure is built, the camera data is entered, and the external parameter calibration is finished by continuous updating and convergence. Finally, the high precision calibration of the binocular stereo vision camera is completed. The results show that the calibration error of the proposed algorithm under different sizes of checkerboard calibration board test is only 0.36% and 0.35%, respectively, the calibration accuracy is high, the value function converges quickly, and the parameter calculation accuracy is high, the overall time consumption of the proposed algorithm is short, and the calibration results have strong stability.Entities:
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Year: 2022 PMID: 35401726 PMCID: PMC8989564 DOI: 10.1155/2022/6596868
Source DB: PubMed Journal: Comput Intell Neurosci
Figure 1Binocular stereo vision measurement.
Camera parameter description.
| Parameter | Expression | Freedom |
|---|---|---|
| Internal parameters | Effective focal length | 5 |
| Nonvertical factor | ||
| Radial distortion parameter | 4 | |
| Tangential distortion parameter | ||
|
| ||
| External parameters | Rotation matrix | 3 |
| Translation matrix | 3 | |
Figure 2Deep reinforcement learning framework.
Figure 3Deep reinforcement learning fitting structure.
Camera performance index.
| Performance index | Numerical value |
|---|---|
| Pixel | 1280 × 960 |
| Sampling frequency | 60 Hz |
| Baseline length | 60 mm |
| Focal length | 6 mm |
| Optical dimension | 1/3 |
Figure 4Chess and card grid calibration board.
Calibration errors of different algorithms.
| Algorithms | Chess and card grid calibration board (mm) | |
|---|---|---|
| 10 | 20 | |
| The proposed algorithm | 0.36 | 0.35 |
| Literature [ | 0.90 | 1.32 |
| Literature [ | 1.66 | 3.27 |
| Literature [ | 1.94 | 2.58 |
| Literature [ | 5.65 | 5.20 |
| Literature [ | 1.74 | 4.22 |
Figure 5Comparison of loss function curve of value function network.
Figure 6Comparison of parameter calculation accuracy.
Comparison of camera calibration time consumption of different algorithms.
| Algorithms | Calibration time consuming (s) | ||
|---|---|---|---|
| KITTI data set | Cityscapes data set | Measurement data set of a vision system | |
| The proposed algorithm | 5.2 | 6.2 | 5.3 |
| Literature [ | 9.2 | 16.5 | 20.2 |
| Literature [ | 7.1 | 14.7 | 21.1 |
| Literature [ | 8.1 | 13.0 | 18.5 |
| Literature [ | 10.4 | 11.1 | 15.4 |
| Literature [ | 9.1 | 12.5 | 49.5 |
Figure 7Stability comparison of calibration results.