Historical:SoC 2008 student proposals

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• name / university / current enrollment
• short bio / overview of your educational background
• did you ever code in C or C++, yes/no? please provide examples of code.
• do you photograph panoramas? please provide examples.
• do you make other use of hugin/panotools than for stitching panoramas? please describe and show examples.
• were you involved in hugin/panotools development in the past? what was your contribution?
• were you involved in other OpenSource development projects in the past? which, when and in what role?
• why have you chosen your development idea and what do you expect from your implementation?
• how much time you plan to invest in the project? (we expected full time 40h/week but better make this explicit)
• please provide a schedule of how this time will be spent on subtasks of the project. While this is only preliminary, be aware that at the beginning of the project you will be required to provide a detailed plan, and during the project you will issue weekly progress reports against that plan.

James Legg, OpenGL Accelerated Hugin Preview

• I am James Legg, a 2^nd year undergraduate in Computer Science and Mathematics at The University of York (UK).
• At university I have taken modules in human computer interaction, artificial intelligence, computer graphics and visualisation, theory of computation, algorithms and data structures, group & ring theory, linear algebra, vector calculus, and analysis among others. I have A-Levels in Physics, Maths, and Further Maths, and a Critical Thinking AS-Level.
• I have experience in C++ and OpenGL, for example I created a program that displays a procedural random terrain, including multiple layers of textures, using OpenGL, SDL (for platform independent event handling), and libnoise (for coherent noise generation). The source is available from http://lankyleggy.members.beeb.net (Download megamap.tar.gz)
• I do photograph panoramas and stitch them with Hugin, there are a few examples at: http://lankyleggy.members.beeb.net/panoramas/
• I also use Hugin for aligning bracketed photos to create HDR images, and I use enblend (and the Gimp) to create seamless textures from photographs. An HDR example and a tonemap are on the same page as linked above.
• I have only recently started contributing to Hugin, see http://groups.google.com/group/hugin-ptx/browse_thread/thread/f94c584095fcb9d0.
• I have not been involved in other open source development projects beyond use, evangelising and bug reporting.
• After completing this project, I expect to have a new optional preview display, acting largely like the existing one. This should instead use OpenGL, and a grid-like mesh to remap the images. It will only be approximate, but still functional. It will not require OpenGL shaders, as the hardware for this is not available to most users, although I would like to make it easy for someone to add this functionality at a later date. The main purpose is to speed up the preview process. Unfortunately, it will not have the accuracy and logarithmic HDR display of the current preview.
• I would like to do this project since I have an interest in computer graphics and human interface design.
• I will invest at least 40 hours a week after the first 3 weeks of the project. Unfortunately the 3rd week of Coding Phase 1 is an exam week, However I will attempt to make up the time before the official coding start date.
• I plan to split the project into the following stages:
  1. Beginnings: I will derive a new panorama preview from Hugin's existing one, set up an OpenGL context for it, and add extra preferences into Hugin to control selection of preview types, and the amount of texture memory and mesh resolution to use. I plan to have this done before the official "Coding starts" date.
  2. Texture creation: After this each image would be scaled appropriately and placed in texture memory.
  3. Photometric Alignment: OpenGL (without shaders) only directly supports linear colour transformations, however after this stage, white balance correction and (approximate) exposure correction will be used to display the images.
  4. Mesh creation: A grid-like mesh will be created for each displayed image. This will then be transformed under distortion correction, input lens projection and output projection, to get the coordinates used to make the display on the preview window. This will require using and extending the current remapping code. I will find a way to track duplicates (e.g. fisheye projections with a FOV > 360 degrees), and to split the mesh across discontinuities in the projection. The final output would then be a linear approximation between the mesh points (along continuous mappings), which is then handled by OpenGL. The results of the mesh transformations will be stored in memory so that changing parameters does not cause unnecessary costly calculations. I expect to have started this by the end of coding phase 1, but I expect this will be the most time consuming stage.
  5. Usability improvements: This will add extra features, e.g. a feature show the outline of an image in the preview, which will hopefully provide quicker identification of images.
  6. Performance enhancing and testing: I will try to improve the performance of my code, and fix any bugs I may have. I will call for testers on the mailing list during this stage, and I may add additional requested features if I have the time. I will also make sure that the documentation is completely up-to-date.

If this feature is not wanted, or mentors are not available, I have an alternative proposal: I would like to make a cube map projection, since cube maps are the most common way of handling static reflections in real-time computer graphics, they should work well with interactive panorama viewers such as FreePV, and it has been requested before.

I would keep the definition of the faces that make the projection generic enough (perhaps specified in a script) to allow shapes other than cubes to be defined (I see there is interest in foldable panoramas and other shapes, including ceating a Pilosphere). This will require work on making enblend and enfuse blend across distinct faces. I don't know any algorithms that can do this well, but I would be willing to research it and experiment.