Focal scanning consistent light field measurement

Focal scanning light field imaging uses a camera to capture images at different focal planes to form an image stack, from which full-pixel-resolution light field information can be computationally recovered, taking advantage of the transport-of-intensity property of light field propagation. In previous work, we experimentally demonstrated that the nonlinear depth mapping between the camera's image and object spaces leads to a discrepancy between image-space capture and object-space reconstruction, significantly affecting the accuracy of light field reconstruction. To this end, we propose a consistent light field measurement method in which the camera is pre-calibrated to establish an accurate transformation relationship between image and object spaces. By transforming the image stack from image space to object space and eliminating the effect of image distortion simultaneously, the space consistency condition is satisfied for light field reconstruction. Subsequently, the transmission distance prior in object space can be obtained to accurately reconstruct the objective light field from the corrected image stack. Since the reconstructed light field in the calibration space exhibits metric properties, metric depth can be further extracted to enable three-dimensional measurement with camera parameters. Experimental results demonstrate that the proposed method is valid and efficient in dealing with the inconsistency issue in focal scanning light field imaging, achieving high-quality consistent light field reconstruction and measurement.