Next Generation CT (Computed Tomography) Student: Jaewon Kim - PowerPoint PPT Presentation

Next Generation CT (Computed Tomography) Student: Jaewon Kim Advisor: Ramesh Raskar Reader: V. Michael Bove Yasuhiro Mukaigawa Fredo Durand

Dream & Goal Dream Thesis Goal Understanding inside of a human body with portable system Wearable, always-on system Non scanning system and visible light for health and HCI (no x-ray CT) Thesis Prototype: 3D finger vein no x-ray CT reconstruction/human Id system

How will CT evolve? 5 th ? 1 st : Linear & rotational CT 2 nd : Multiple scanning CT Non-scanning No Synchronization Compact Safe 3 rd : Fan-beam CT 4 th : spiral CT or helical CT

Traditional CT Benefit  See through human body with X-ray Limitation: Scanning mechanism makes CT large and cumbersome  Expensive  Exposure to X-rays  Poor dynamic volume reconstruction Standard CT system

Thesis Goal  A. Avoid mechanical scanning (Also applicable to actual X-ray CT system) Single shot CT of translucent (non-scattering) objects  B. Visible light CT and overcome scattering Imaging through scattering objects

Goal A: Non scanning CT Prior work Shield Field Imaging (Lanman, Raskar, Agrawal and Gabriel[2008] )  Opaque object reconstruction from a single photo  Limitation : Lacks support for translucent object A single shot photo Shield Field system 3D Reconstruction Decoupling to multi-view images

Goal A: Non scanning CT My contribution 3D Reconstruction of partially transparent objects with a single shot photo  Limitation : low resolution due to decoded multi-view images single shot photo Single shot CT setup 3D Reconstruction Decoded multi-view images

Goal A: Non scanning CT My contribution Reconstruction of partially transparent objects using visible light Multi-view images(resolution is 100x200) 3D reconstruction results in high resolution

Goal B: Visible light CT Prior work Separation of Direct and Scattered component of reflection (Nayar, Krishnan, Grossberg and Raskar [2006] )  Reflection-based method using projected patterns  Limitation : not single shot, no 3d reconstruction, no transmission mode = + Scattered component Direct Image Photo of mannequin and shower curtain

Goal B: Visible light CT My contribution Transmission-Mode Direct-Global Separation of Scattering Objects (will be submitted to CVPR 2010)  a single LED and lenslet(pinhole) array method  Acquiring a clear image for objects inside of scattering media + = Photo of mannequin Direct Image Scattered component and shower curtain Imaging Setup

Example Application Single shot 3D vein reconstruction Finger vein imaging using near-infrared LED by Hitachi and Sony vein authentication+lightfield camera Near-infrared image of finger vein (ML disclosure filed as  3D Finger Vein Authentication  )

Limitations & Future directions Limitations  Difficult to see through dense area of a human body with visible light  Decreased resolution of processed light field images  Need for multiple light sources for non scanning CT system Future  Replacing traditional CT system by single shot compact system  Health and HCI applications with portable and safe CT machines  Self imaging of CT images by patients

Evaluation Goal A: dynamic volume reconstruction of translucent objects with a resolution of 100x200x200 Evaluation: Comparing 3D reconstruction results in proposed and normal tomographic techniques Comparing SNR between lightfield and normal images Goal B: 3D finger vein CT system with a resolution of 100x100x100 Evaluation: Id using vein pattern from 20 people database by 3D matching

Dream & Goal Dream Thesis Goal Understanding inside of a human body with portable system Wearable, always-on system Non scanning system and visible light for health and HCI (no x-ray CT) Thesis Prototype: 3D finger vein no x-ray CT reconstruction/human Id system