Confessions of a researchaholic

Basically, its main function is to be displayed on the front of the room during the committee meeting, so that people can have a visual reference/cue of the paper being talked about.
Even though the representative image does not have any practical value for the paper (it is not illegal to use an arbitrary image, like, say, picture of Lindsay Lohan, at least with clothes on), the committee members are humans and thus can be subtly influenced by all psychological factors.
Thus, it is to your advantage to use an image that can help your paper, i.e. conveys the main ideas or results while looks appealing.

Every research paper has to cite and describe relevant previous works, often in a dedicated previous work section, or sometimes as part of the introduction.
Trying to write a previous work section can be an excellent mirror exercise for reading papers. The quality of the former can be a good indication of how much you really understand from the latter.

First of all, spend enough time reading how other people write previous work sections. Pay particular attention to those you find educational, from which you can actually learn something, as well as those you find unhelpful, from which you feel only confusion and frustration.

A good previous work section contains multiple layers of information with different resolutions of details.

• At the bottom level (highest resolution), you describe in one or a few sentences about the gist and merits of each paper.

• At the middle level (medium resolution), you organize related papers into paragraphs, each contains information about the gist and merits of the group.

• At the top level (lowest resolution), you relate every citation with your paper, in particular, how yours stands on the shoulders of previous giants: commonalities, inheritances, and mostly importantly, innovations.

After you have a draft, show it to your adviser or other experienced researchers, ask for advice, and iteratively improve it. It will be an excellent exercise for both reading and writing papers.

Many mentors have their own favorite entry level project for both training and sieving purposes. And mine is ray tracing.

Read + code

Read the following books and implement your own ray tracer from scratch.
Yes, I mean writing every single line of the code yourself, except for standard libraries like iostream and cmath. And yes, I recommend c++ as the programming language.

Ray tracing in one weekend, by Peter Shirley.
Path tracing with soft phenomena. Very short and cute introduction to ray tracing in particular and computer graphics in general. Full of hidden gems and wisdom, but beginners might not appreciate all the nuances.

An introduction to ray tracing, by Eric Haines, Pat Hanrahan, Rob Cook, Jim Arvo, David Kirk, Paul Heckbert, and (edited by) Andrew Glassner.
Whitted-style ray tracing with hard phenomena. More comprehensive than the book above.

You should read the books (especially the first one) on a computer and code along. Do not just read; it is less fun and less effective.
Software engineer your code from the very beginning; ray tracing is nicely object oriented with natural object-like components such as rays, shapes, materials, colors, motions, and cameras.

Demo

Produce your own ray traced images. Start with something simple, like mirrors and glasses for basic reflections and refractions. Ultimately, I want to see 2 things:

• Produce ray traced animations from the BART benchmark. (If you can reach this stage, I consider your training complete. If you cannot even get to this point for whatever reason, you have no chance to survive in our future projects.)
• Design your own favorite scene, and ray trace it. Show me your creativity and artistic + scientific blend. You can find examples from prior Stanford cs348b rendering competitions.
  (This part can be good for a group project, even though I expect everyone to complete everything else individually.)

Why

I did ray tracing as part of Stanford CS348b image synthesis, and I would say this is perhaps the class that I have learned the most from.
First, ray tracing is a superb training for coding and software engineering; it is inherently modular and suitable for object oriented programming, and the amount of coding is non-trivial (actually, quite hefty for new-comers, especially if you code from scratch).
Second, ray tracing is a superb introduction to image formation, and you will learn the fundamentals of physics, computer graphics, computer vision, and image processing.
Third, and perhaps most importantly, it is heck of fun. It is beyond words for me to describe the satisfaction I (and many people I heard from) derived from producing my first ray traced image. I am not an artist, but I can paint with algorithms.

P.S.

There is another excellent book for ray tracing: Physically based rendering, by Matt Pharr and Greg Humphreys, but I personal opinion is that you should read it as your second, not first, ray tracing book.

Sylvain Lefebvre has a nice post about how to structure code for producing research results; see here. (Full disclosure: Sylvain is my collaborator, but he is a superb researcher and coder, as evident from his resume.)