Kim, J. "Next Generation CT"

Abstract

In this thesis, two novel techniques for future CAT system are presented. Transmission descattering technique is a single-shot method to differentiate unscattered and scattered components of light transmission through a heterogeneous scattering material. Directly-transmitted components travel in a straight line from the light source, while scattered components originate from multiple scattering centers in the volume. In the technique, angularly varying scattered light is strategically captured via a lenslet array placed close to the image plane and the unscattered direct component is computed based on separable scattered components. The disadvantage is a reduction in spatial resolution. As an application, the enhanced tomographic reconstruction of scattering objects is demonstrated using estimated direct transmission images. The other technique is single-shot 3D reconstruction of a translucent object. In the experimental setup, multiple light sources form images of a translucent object at different projection angles onto a screen. Those images are captured by a single-photo in a coded format via lenslet array. The projection image casted from each light source is separated from each other by a decoding process and in turn the images are combined to reconstruct 3D shape of the translucent object by ART method.