The effect of geometric parameter errors on Computed Laminography three-dimensional reconstruction

Errors in the installation and design of Computed Laminography (CL) systems can lead to inaccuracies in the geometric parameters used for 3D reconstruction algorithms, affecting the quality of reconstructed images. CL systems are especially susceptible to geometric parameter errors due to the tilt of the rotation axis. This study investigates the relationship between different geometric parameter errors and the features of reconstructed images in CL systems. The projection derivative address formula is derived to analyze the impact of geometric parameter errors on object projection trajectories at different positions within the CL system. Reconstruction experiments using both the FBP algorithm and the SART algorithm combining with total variation (TV) regularization are conducted on printed circuit board (PCB) modalities. Results show that each geometric parameter error induces distinct artifacts in the reconstructed image at various locations. These findings provide a theoretical guide for identifying and rectifying sources of geometric parameter errors during the installation and geometric correction processes in industrial CL systems. Finally, practical experiments conducted on PCB samples validate the study's conclusions.