View source for SoC2007 projects

= Introduction =

This is the work in progress list of possible projects for the [[Google_SoC_2007]]

Panoramic imaging is a very broad field and touches many different areas of expertise, such as photography, computer vision, art and programming.
There is a thriving community with experience from arts to science that provides many interesting ideas and explores new territory in panoramic imaging. In addition to the mentors, this open community will provide good support and innovative ideas.

Generally, all development should done with multiple platforms in mind (at least Windows, OSX and Linux/Unix). We have an open communication culture via mailing-lists and mostly develop using C and C++.

The project below are just suggestions. If you are an interested student and have questions or new ideas, please let us know on the relevant [[Discussion_lists]], for example [https://lists.sourceforge.net/lists/listinfo/panotools-devel panotools-devel].

= Development style =

Most of the projects below are related to [[Hugin]], and some also relate to [[Panotools]] or [[tlalli]]. [[Hugin]] is mostly written in C++, and uses the [http://kogs-www.informatik.uni-hamburg.de/~koethe/vigra/ VIGRA image processing library] to support different types of images (for example, 8bit, 16bit and float (HDR) images). The core functionality is implemented in a platform independent C++ library, which is used by the GUI based on wxWidgets toolkit, and the command line programs ([nona], [[fulla]]).

The development of the projects should take place in a separate branch of the projects CVS (or SVN) repository. Communication with the mentors should usually happen through the appropriate development mailing list. All code should work on the major platforms supported (Linux, OSX, Windows).

= Possible Projects =

== Intuitive yet powerful GUI for panorama creation ==

Goal: Redesign/Reimplement the graphical user interface of the premiere open source panoramic imaging suite, [[Hugin]], to increase ease of use, and provide better access to its unmatched capabilities. Currently the GUI is written using [http://www.wxwidgets.org wxWidgets], which has proven to have slightly different behaviours on different platforms, especially with a complex GUI such as the one of Hugin. This is very annoying and a lot of time has been spent on minor issues such as making the GUI look good on all platforms with different font sizes etc. Therefore two steps are possible:

1. Rewrite the whole GUI using QT (which is very consistent even across platforms, and has (IMHO) a much nicer API). This is a lot more work, and not all functionality of the current GUI can be recreated during the Summer of Code, but it will provide a better platform to build onto in the future. It is also possible to implement the GUI logic in a scripting language such as Ruby or Python. This project should only be tackled by a student who has experience in developing non-trivial GUI applications with QT. The GUI and core panorama code are already separated into different libraries.

2. Extend the existing wxWidgets based GUI.

General goals for the improved GUI include:

* Providing a simple, yet helpful user interface that suggests or highlights potentially useful next steps.
* Enhancing and integrating manual and automated control point placement and management.
* Improving lens parameter management.
* Providing a batch processing interface.
* Expert mode with access to all features and internals.

Recommended knowledge or interest in:
* Workflow analysis and UI design skills
* Experience with building cross platform GUI programs (Windows/Linux/OSX), either using wxWidgets or QT
* Creative use of panoramic imaging

Mentor: Pablo d'Angelo, ?

License: GPL

== Automatic feature matching for panoramic images ==

Goal: Robust matching of features between multiple images using a Hessian-based detector and a suitable descriptor.
A detector and descriptor that takes into account the approximately known distortions will have a much higher matching rate, especially when fisheye or wide angle images are used. 

This project should be split into two projects, which could be done by separate students:
* Implementation of the feature detector and descriptor, and a suitable test suite to verify the correctness of the implementation.
* Implementation of the matching step, including geometry based outlier pruning (for example using RANSAC) and fast nearest neighbour matching, possibly using a fast algorithm such as cover trees.

A desired result of the projects would be:
* C or C++ library that implements the detection and description steps.
* C or C++ library for the matching step.
* Integration of both libraries into [[hugin]] and a standalone executable similar to [[Autopano-sift]] or [[Autopano]]

Required knowledge or interest in:
* signal or image processing background
* C or C++ development skills.
* Matlab or octave

Literature about feature detection
* [http://en.wikipedia.org/wiki/Scale-invariant_feature_transform Wikipedia article on SIFT], contains several good references
* [http://homes.esat.kuleuven.be/%7Etuytelaa/ECCV06tutorial.html Tutorial on local invariant features]
* [http://www.mis.informatik.tu-darmstadt.de/Education/Courses/cv/index.html Lecture notes] on feature detection/matching]
* Framework for [http://www.robots.ox.ac.uk/~vgg/research/affine/ testing descriptors]

Possibly useful resources and libraries:
* [http://hunch.net/~jl/projects/cover_tree/cover_tree.html Fast nearest neighbour matching using cover trees]
* [http://kogs-www.informatik.uni-hamburg.de/~koethe/vigra/  VIGRA computer vision library]

Mentor: Pablo d'Angelo, Herbert Bay, ?

License: GPL

== Interactive panoramic viewer ==

Goal: The [[Freepv]] panoramic viewer aims to provide a superior viewing experience
for panoramas on all major platforms (Windows, Mac and Linux/Unix), based on
exploiting powerful graphics hardware using OpenGL. Currently it provides
basic but solid viewing capabilities for Quicktime VR, cylindrical, cubic and equi-rectangular panoramas. Plugins for Mozilla/Firefox and a standalone viewer are available. Several important features are still missing from the viewer include:

* Support for hotspots
* Optimisation for panoramas larger than the Video RAM
* Display of high dynamic range panoramas with adaptive exposure
* Support for reading a SPi-V compatible .xml file, for platforms where SPi-V is not available (Linux/Unix).
* Fallback software renderer

Required knowledge or interest in:
* OpenGL or other 3D programming experience.
* Creating cool and nice looking interactive experiences.

Mentor: Pablo d'Angelo, ?

License: LGPL

== Anti-ghosting HDR panorama blending and merging algorithm ==

Goal: Most HDR creation algorithms are designed to work only with very small variations in camera viewing direction. Assume that registration and response curve estimation has already happened. An improved blending method for HDR images together that have not been shot using the traditional exposure stack method. It should avoid ghosting and be insensitive to small misregistrations. 

Interesting research papers:
* [http://www.cs.berkeley.edu/~eden/737_eden_a.pdf Seamless Image Stitching of Scenes with Large Motions and Exposure Differences]
* [http://graphics.cs.ucf.edu/ekhan/project_ghost.htm Ghost Removal in High Dynamic Range Images]

Required knowledge or interest in:
* Strong background signal/image processing
* Creative mind with ideas beyond the state of the art in computer vision/graphics research.

Mentor: Pablo d'Angelo, ?

License: GPL

== Processing of very large images ==

Goal: Allow the creation of arbitrary large panoramas.
[http://flickr.com/groups/83823859@N00/discuss/72157594574253488/]

Currently panotools, as well as hugin/nona require memory to hold the complete input and the remapped output image in memory, which consumes a lot of RAM, especially for spherical panoramas. [http://www.vips.ecs.soton.ac.uk/ VIPS] is a powerful and modular image processing library that supports very large images and multiple processors natively. By porting the core remapping routines of panotools/hugin to VIPS, panoramas of almost arbitrary size can be computed.

A desired result of the projects would be:
* VIPS operations that support the geometric and photometric (vignetting correction) transformations.
* Standalone command line program that remaps images using these routines.
* Program/script to convert panotools scripts to nip2 projects.

Required knowledge or interest in:
* C/C++ programming
* image processing

Mentor: John Cupitt, Pablo d'Angelo

License: GPL


== Architectural Overhaul of Panotools ==

Panotools is a very monolithic application. The goal of this project is to refactor the functionality of panotools into 4 main parts, as independent of each other as possible.
These parts are (at least):

* Calculation of position of images (optimization)
* Mapping from input images to output images
* Projection related computations
* Parsing of input scripts/Generation of input scripts

Were this project successful the functionality of panotools will be available as a collection of routines that be called directly (as opposed to the current model that requires
the creation and parsing of a script). It will  make it easier to replace one component of panotools with another one; and it will improve the future maintenance of panotools.

A desired result of the projects would be:
* Set of functions/classes that are available to hugin to perform optimization and remapping of images
* Test suite to verify that the functionality before and after is equivalent.

Required knowledge or interest in:
* C/C++ programming
* Knowledge of Numerical methods
* Basic knowledge of image processing

Mentor: D.M. German

License: GPL