Fig. 1. Three-dimensional scanning system of the lidar. (a) Coordinate system of the lidar; (b) on-axis coordinate system
Fig. 2. Distance from the origin of the left and right coordinate systems to the plane
Fig. 3. Principle of the camera-lidar system
Fig. 4. Filtering result of the point cloud. (a) Cross-sectional view of the point cloud; (b) processing result of the radius filtering algorithm
Fig. 5. Coordinate system of the virtual camera
Fig. 6. Physical image of the camera-lidar system. (a) Front view; (b) back view
Fig. 7. Effect of parameter verification. (a) Before calibration; (b) after calibration; (c) room model
Fig. 8. Environment of the joint calibration experiment
Fig. 9. Grayscale images of different pixel sizes (a) Pixel size is too large; (b) pixel size is too small; (c) pixel size is moderate
Fig. 10. SIFT feature point matching graph
Fig. 11. Variation curve of the reprodjection error
Fig. 12. Result of data fusion. (a) Fusion environment; (b) fusion effect
Parameter | | | | |
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Calibration result | 1055.5179 | 1052.952 | 649.637 | 485.239 |
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Table 1. Camera parameters after calibration
Calibration parameter | (°) | (°) | m | m |
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Calibration result | 1.41 | -0.15 | 0. 001 | 0.002 |
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Table 2. Self-calibration results of lidar
Length | | Width | | Height |
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Measured value | Error | Measured value | Error | Measured value | Error | 646.9 | 1.6 | 622.7 | 1.3 | 259.7 | 1.5 |
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Table 3. Comparison of room size
Rotation matrix | Translation matrix |
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| |
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Table 4. Calibration result
Method | Number of checkers | Reprojection error /pixel |
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Ours | 0 | 2.29 | Ref.[16] | 6 | 3.51 |
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Table 5. Reprojection errors of different methods