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Diffusion Coded Photography for Extended Depth of Field SIGGRAPH 2010. Oliver Cossairt, Changyin Zhou, Shree Nayar Columbia University. Supported by ONR and NSF. Conventional Camera (F/1.8). Conventional Camera (F/18). Camera Blur Model. Spatial domain. PSF. Focused Image.
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Diffusion Coded Photography for Extended Depth of FieldSIGGRAPH 2010 Oliver Cossairt, Changyin Zhou, Shree NayarColumbia University Supported by ONR and NSF
Camera Blur Model Spatial domain PSF Focused Image Captured Image Image Noise Frequency domain Focused Image MTF Image Noise Captured Image (Modulated Transfer Function)
Deblurring Problems Low SNR Focused image Problem 2: Sensor Object P Q Lens Problem 1: Low MTF values Captured image MTF Variation with depth
Extending Depth of Field (EDOF): Previous Work Focal Sweep Cameras [Hausler ’72] [Nagahara et al. ’08] Wavefront Coding Cameras [Dowski and Cathey ’95] [Chi and George ’01] [Garcia-Guerrero et al. ‘07] Cubic Phase Plate Sensor Lens Sensor Lens Focal Plane Other Related Work [Levin et al. ’07] [Veeraraghavan et al. ’07] [Levin et al. ’09]
near far focus Conventional Camera depth Focal Sweep Wavefront Coding Focal sweep vs. wavefront coding Note: only a single PSF will be used to deblur the whole image.
Focal sweep vs. wavefront coding Deblurring Error vs. Depth Deblurring Error noise Depth Focal Sweep Wavefront Coding
Achieve the performance of focal sweep without any moving parts?
SEM image Diffuser sheets x Scatter function Light ray w x w Diffuser Sensor Optical Diffusers Diffuser [http://www.luminitco.com]
Sensor Diffuser Kernels Without a diffuser: Light Field u x u A/2 x A -A/2 Lens
Sensor Sensor Diffuser Kernels Without a diffuser: Light Field u x u A/2 x A -A/2 Lens With a diffuser: u x u A/2 x A -A/2 Lens
Sensor Sensor Diffuser Kernels Without a diffuser: Light Field u x u A/2 x A -A/2 Lens With a diffuser: u x u A/2 x A -A/2 Lens
A/2 -A/2 Diffusion Kernels Without diffuser Diffuser kernel With diffuser u u u Light field x x x
A/2 project project project -A/2 x x x Diffusion Kernels Without diffuser Diffuser kernel With diffuser u u u Light field x x x PSF Camera PSF Scatter function Diffused PSF
Radially Symmetric Diffuser Without a diffuser: PSF Lens Sensor
Radially Symmetric Diffuser Without a diffuser: PSF Lens Sensor With a diffuser: Lens Sensor
Radially Symmetric Diffuser Without a diffuser: PSF Lens Sensor With a diffuser: Lens Sensor
Radially Symmetric Diffuser Without a diffuser: PSF Lens Sensor With a diffuser: Lens Sensor
Radially Symmetric Diffuser Without a diffuser: PSF Lens Sensor With a diffuser: Lens Sensor
Radially Symmetric Diffuser Without a diffuser: PSF Lens Sensor With a diffuser: Lens Sensor
Radially Symmetric Diffuser Without a diffuser: PSF Lens Sensor With a diffuser: Lens Sensor
Radially Symmetric Diffuser -50px 50px -50px 50px -50px 50px -50px 50px Scatter function Camera PSF PSF: PSF (1D slice) MTF (1D slice) Normalized frequency Normalized frequency Normalized frequency Normalized frequency depth
Diffusion Coding Performance Diffusion Coding (light field) Diffusion Coding (wave optics) Deblurring Error vs. Depth Wavefront Coding Focus Sweep Deblurring Error noise Depth Similar performance to focal sweep without moving parts
Diffuser Implementation Diffuser scatter function r(mm) Diffuser height map Fabricated diffuser Diffuser surface profile 3 2 RPC Photonics Thickness (um) [www.rpcphotonics.com] 1 6 0 3 8 11 r(mm)
Comparison with Prior Work x Deblurring Error vs. Depth Diffusion Coding Garcia-Guerrero Deblurring Error Depth Diffusion coding significantly outperforms prior work.
Measured PSFs Without diffuser With diffuser depth Diffusion Coding Experiments Experimental Setup Fabricated Diffuser Cannon 50mm EF lens Cannon 450D Sensor
Stuffed Toys Conventional Camera f-number = 1.8, exposure time = 16ms
Stuffed Toys Conventional Camera f-number = 18 , exposure time = 16ms
Stuffed Toys Diffusion Coding Camera: Captured f-number = 1.8, exposure time = 16ms
Stuffed Toys Diffusion Coding Camera: Deblurred f-number = 1.8, exposure time = 16ms
Statues Deblurred Captured f-number = 1.8; exposure time = 10ms
People and Flowers Conventional Camera f-number = 1.8, exposure time = 16ms
People and Flowers Diffusion Coding Camera: Captured f-number = 1.8, exposure time = 16ms
People and Flowers Diffusion Coding Camera: Deblurred f-number = 1.8, exposure time = 16ms
Loss of contrast • Occlusion errors Limitations Conventional Camera Diffusion Coding • Loss of image texture
Radially Symmetric Diffusers Diffusion Coding Examples Diffusion Coding Implementation Conclusions Diffusion Coding Theory
Diffusion Coded Photography for Extended Depth of FieldSIGGRAPH 2010 Oliver Cossairt, Changyin Zhou, Shree NayarColumbia University Supported by ONR and NSF