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Processing Digital Camera Images WS 11/12
English/Deutsch?
Language
Responsible:
• Prof. Dr. Marc Alexa, Prof. Dr. Bernd Bickel
Main contact:
• Mathias Eitz - [email protected]
• EN 721
Administration:
• Helga Kallan - [email protected]
• EN 716
We
Have to work in teams - introduce yourself…
• CS Student?
• Graphics/Vision classes taken
• Programming experience
• Why interested in this course
Register for course on www.cg.tu-berlin.de
You
Basic Image Processing
• Convolution, Morphological operators, Filters
• But might need those as building blocks for projects
Photoshop
• Won’t learn how to use Photoshop
• Theory of some advanced PS features might be covered (Panorama function of CS3 uses recent research results)
Photography
• Won’t learn how to take good pictures
• But might need to take pictures for some projects
What this course is not about
Computational Photography
• Epsilon Photography
• Take multiple pics with varying camera parameters
• E.g.: HDR, Panorama
• Coded Photography
• Modifying camera lens to achieve a certain goal
• E.g.: Deblurring, light field capture, relighting, dark flash
• Data driven Vision and Graphics
• Beyond the human eye
• E.g.: Photo tourism, scene completion
What this course is about
Problem: limited field of view of digital cameras
• Compact camera: 50x35º
• Human: 200x135º
• Panorama 360x180º
Panoramic Images
Early panoramic images:
• View from the top of Lookout Mountain, Tennessee1864, by George N. Barnard
Panoramic Images
Image: Wikipedia
Problem: limited contrast of digital cameras
High Dynamic Range Imaging
Images: Fattal et al.
[Fattal et al.]
Solution:
• Take multiple pictures, vary exposure time
• “Combine” shots to produce a single “HDR” image
High Dynamic Range Imaging
“Combine” exposures into high dynamic range map
• Each pixel represents real world radiance
New problem: how to display on LCD?
Recovering HDR
Approach [Fattal et al.]
• Attenuate strong contrast edges
• Reconstruct image
Tone mapping
Gradient Domain Imaging
Usually, we directly manipulate (RGB) pixels
Working in gradient domain can have advantages:
• Modifying image edges becomes easier
• Blending becomes easier
Problem: unwanted motion blur
Fluttered Shutter [Raskar et al.]
Traditional camera: shutter is always open
Fluttered Shutter
Fluttered Shutter: Distinct open close pattern
Fluttered Shutter
Deblurred result
Fluttered Shutter
Problem: How to resize an image?
• Scaling/Cropping/Seam Carving?
Seam Carving [Avidan & Shamir]
scaled cropped seam carved
Seam Carving
Patchmatch [Barnes et al.]
What can we do with millions of
images?
Replace unwanted object in an image
Scene Completion [Hays et al.]
Find similar scenes from large image collection
Copy & blend missing area
Scene Completion
Photo Tourism [Snavely et al.]
Live demo: http://phototour.cs.washington.edu
Overview/Introduction of topics: 18.10., 25.10.
Basic Talks: 01.11. ~ 15.11.
• Teams start their project by preparing basic talk
• Talk covers important aspect that is useful in itself
Project roadmap: 22.11.
• Slides presented in class: list milestones, relevant papers
Implementation project: 22.11. – 07.02.
• Project presentations & demos: 07.02., 14.02.
Documentation (online): 21.02.
Approximate schedule
Attendance mandatory, we keep a list
Grading
• Attendance & participation: 10%
• Basic talk: 20%
• Project roadmap: 10%
• Project (implementation): 40%
• Documentation (online): 20%
Rules I
Reuse existing resources, but
• Must give referencs
• Example: you may use illustrations in your talk taken from other slides, but add a note such as [image: taken from Alexa et al.]
• For some of your projects rather complete implementations are available on the web – use them for inspiration, do not copy!
• If in doubt, ask Mathias
Rules II
Check last years’ projects
• Links are on the course website
• Browse similar course homepages @ MIT, Stanford, Brown
Check our project list (online Friday)
• Find at least two projects you are interested in
• After class contact potential team members
Register for this course
Todo until next week
Similar courses:
• http://www.cs.brown.edu/courses/csci2951-b/
• http://www.cs.brown.edu/courses/csci1290/
• http://graphics.cs.cmu.edu/courses/15-463/
• http://www.cc.gatech.edu/classes/AY2005/cs4803cp_summer/
• http://graphics.stanford.edu/courses/cs448-04-spring/
• http://people.csail.mit.edu/fredo/PhotoSeminar05/
• http://cs.nyu.edu/~fergus/teaching/comp_photo/
• http://www.cs.unc.edu/~lazebnik/research/fall08/
• http://cameraculture.media.mit.edu/Fall2010ComputationalCamera
Resources - I
Finding papers:
• http://scholar.google.com/
SIGGRAPH coursenotes
• http://web.media.mit.edu/~raskar/photo/
Books:
• http://szeliski.org/Book/
• http://www.amazon.com/dp/1568813139/
Resources - II
Image/Video References:
• Connelly Barnes, Eli Shechtman, Adam Finkelstein, Dan B Goldman - PatchMatch: A Randomized Correspondence Algorithm for Structural Image Editing���ACM Transactions on Graphics (Proc. SIGGRAPH), 2009
• Shai Avidan and Ariel Shamir. Seam carving for content-aware image resizing. ACM Transactions on Graphics (Proc. SIGGRAPH), 2007
• Noah Snavely, Steven M. Seitz, Richard Szeliski, Photo tourism: Exploring photo collections in 3D, ACM Transactions on Graphics (Proc. SIGGRAPH), 2006
• Ramesh Raskar, Amit Agrawal, and Jack Tumblin, Coded Exposure Photography: Motion Deblurring using Fluttered Shutter, ACM SIGGRAPH, 2006
• James Hays, Alexei A. Efros. Scene Completion Using Millions of Photographs. ACM Transactions on Graphics (Proc. SIGGRAPH), 2007
• R. Fattal, D. Lischinski and M. Werman,Gradient Domain High Dynamic Range Compression, ACM Transactions on Graphics (Proc. SIGGRAPH), 2002
Resources – III