3D-DCT Coding for Video Editing, Low-Power Devices, and Medical Imaging

This paper examines the Three-Dimensional Discrete Cosine Transform (3D-DCT), an extension of the widely used 1D- and 2D-DCT families that underpin modern audio, image, and video compression standards. Although extensively studied in theory, the 3D-DCT remains far less explored in practical coding systems. In this work, we develop a simple yet complete 3D-DCT encoder and investigate its performance in several application domains. By stacking video frames into 3D blocks and applying cubic or non-cubic 3D-DCT transforms, we construct a video coder that is significantly simpler than MPEG-x/H.26x methods while achieving comparable compression efficiency. The proposed approach is also well-suited for video editing scenarios, where small GOP sizes and the absence of motion dependencies provide improved frame-level accessibility. In addition, we evaluate the use of 3D-DCT for compressing volumetric medical images (CT studies), demonstrating strong quality and compression performance. Since 3D-DCT naturally applies to any 3D dataset, the method is likewise applicable to MRI or LIDAR volumetric data. Overall, the results show that 3D-DCT offers a versatile and computationally simple alternative for both video compression and 3D image coding.