Generalized Image Acquisition and Analysis

Time-resolved 3D Capture of Non-stationary Gas Flows

Fluid simulation is one of the most active research areas in computer graphics. However, it remains difficult to obtain measurements of real fluid flows for validation of the simulated data. In this paper, we take a step in the direction of capturing flow data for such purposes. Specifically, we present the first time-resolved Schlieren tomography system for capturing full 3D, non-stationary gas flows on a dense volumetric grid. Schlieren tomography uses 2D ray deflection measurements to reconstruct a time-varying grid of 3D refractive index values, which directly correspond to physical properties of the flow. We derive a new solution for this reconstruction problem that lends itself to efficient algorithms to robustly work with relatively small numbers of cameras. Our physical system is easy to set up, and consists of an array of relatively low cost rolling-shutter camcorders that are synchronized with a new approach. We demonstrate our method with real measurements, and analyze precision with synthetic data for which ground truth information is available.


Computational Optical Imaging

Lecture in winter term 2014/15

Lecturer: Ivo Ihrke

General Information

Course webpage - Libres Savoirs

When: 2014, Sept. 08th to 2014, Oct. 8th
Where: IOA/IOGS buiding room E202
Registration for mailing list: send email to Ivo Ihrke (firstname[dot]lastname[at]


This lecture covers advanced digital imaging techniques for image correction and calibration, as well as algorithms and optical considerations for the extraction of three-dimensional content from (sets of) images. We explore the notion of computional-optical codesign and modern high-dimensional imaging techniques.

The tentative course schedule is

Monday 08.09.2014 Introduction and Recapitulation of Image Characteristics [pdf intro & recap]
Wednesday 10.09.2014 High Dynamic Range, Spectral, and Polarization Imaging [pdf hdr/spectral/polarization]
Monday 15.09.2013 Deconvolution [pdf deconvolution]
Wednesday 17.09.2013 Perspective Imaging and the Basics of 3D
Monday 22.09.2013 Structure-from-Motion
Wednesday 24.09.2013 Dense Stereo Techniques and Optical Flow
Monday 29.09.2013 Active 3D Scanning
Wednesday 01.10.2013 Tomography and Volumetric 3D
Monday 06.10.2013 Light Fields
Wednesday 08.10.2014 to be determined - possibly Compressed Sensing


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