Virtual unrolling technology based on terahertz computed tomography

•For the first time, a virtual unfolding/unrolling technique based on terahertz waves is proposed, and experimentally comparable results with transmission imaging are obtained.•An abstract model of a general folded or scroll structure is proposed.•Based on the existing techniques, a scheme centered on image segmentation and inpainting is proposed to effectively cope with the severe terahertz CT metal artifact problem.•A geometric feature-based ridgeline detection algorithm and K3M skeletal line extraction algorithm are integrated to accomplish the extraction of single pixel width profile line for each slice image.•A Match-Graft approach based on Dynamic Exemplar (MGDE) is creatively proposed to complete image stitching.