Fig 1.
The overall framework of the PBOF using the CSP.
The complex filter rotation angle θ = 0.
Fig 2.
The oriented band-pass filters of the four types of CSP at level 1 and rotation angle 0.
(a) Octave. (b) HalfOctave. (c) SmoothHalfOctave. (d) QuarterOctave.
Fig 3.
The pseudocode of the Octave CSP filter decomposition image algorithm.
Fig 4.
Performance evaluation flow chart of motion parameter measurement with PBOF using four types of CSP.
Fig 5.
Simulated speckle reference image.
Fig 6.
The x direction displacements provided by the data in Section 3.2.2.
Fig 7.
Experimental speckle reference image.
Fig 8.
The x direction displacements provided by the data in Section 3.3.
Fig 9.
The displacement measurement accuracy of PBOF using the most accurate filters of CSP under various downsampling rates.
(a) The value of AE across all frames. (b) The average value of RE across all frames. HO, SHO, and QO respectively represent HalfOctave, SmoothHalfOctave, and QuarterOctave.
Fig 10.
The minimum value of effective measurement displacement (EMD) obtained by PBOF using the effective level filters of each CSP.
Fig 11.
The maximum value of effective measurement displacement (EMD) obtained by PBOF using the effective level filters of each CSP.
Fig 12.
Within the micro-displacement interval (MDI) and the effective displacement measurement interval (EDMI), the average value of AE and the average value of RE of PBOF across all measurement frames using the effective level filters of CSP.
(a) Octave. (b) HalfOctave. (c) SmoothHalfOctave. (d) QuarterOctave.
Fig 13.
The RE of each frame image is measured in the simulated image sequence by PBOF using the most accurate filter of each CSP.
Fig 14.
The minimum value of EMD obtained by PBOF using the effective level filters of each of CSP.
Fig 15.
The average value of RE obtained by PBOF using the effective level filters of each CSP.
Table 1.
The VAAE (pixel), RMSE (pixel), and MFABE (Hz) of the measured vibration displacement obtained by PBOF using the effective level filters of each CSP.