dipityPix app

Monday, October 15, 2012

Gortler's graphics book is out

Steve (Shlomo) Gortler's intro graphics text is out.  It's a sweet book, and is nicely priced.  Shlomo was nice enough to sit down and take me through his favorite part: handling points, vectors, and transforms.  One of the things that is a pain in the neck in graphics is managing coordinate systems.  Most books assume a canonical coordinate system and then introduce some Phigs-like hierarchy.  This book makes coordinate systems a first class citizen, while keeping the math elegant as those of you who've read Shlomo's papers know is his habit.  I think he may have found the sweet spot of how to handle this, and he says teaching from it has gone well.  I would love to hear others' experience and am anxious to give it a try in code (the code he showed me makes me think it may be really clean).

My favorite part is surely his color chapter.  I've often tried to develop why the weird XYZ space is the way it is, and what the relationship between the weighting functions (like x(lambda)) and the lights are (nonphysical for XYZ).  He's totally nailed it.  This treatment totally lives up to the "Foundations" part of the title.  I have not yet read the rest of the book, but this chapter alone was worth buying it in my opinion.

Wednesday, September 26, 2012

2012 Updates

In my effort to have the lamest blog in the history of academics that somehow wont die, here is an update for 2012.  Just a bunch of random stuff.

Peter-Pike Sloan and I have an office-mate for a year while he's visiting from his ongoing post at Iowa: Chris Wyman.   When I first met these two I knew a lot and they knew a little.  Actually let's not go there.

I am giving a physically-based rendering course at SIGGRAPH Asia in Singapore this year.   I'm very curious to attend and look forward to it.  Given that TOG papers are now presented at SIGGRAPH I finally think the technical program at SIGGRAPH (both) has a bandwidth that approximately matches the good papers being submitted, so optimistic.  Please comment if there are cool things to see at the conference or in Singapore in general.

I upgrade my laptop whenever there are big improvements in screen technology.  I got the lowest end MacBook Retina display (with lovely nvidia graphics of course) and am in love.  I finally can shed the desktop as it turns out that all these years I wanted a big screen for all the pixels and not the size of the screen.

I am 99.9% recovered from my car wreck a year ago.  If you can afford it, buy side-air bags.  Note I ignored that advice so I expect you all to as well!

The trend in graphics people writing iPhone apps continues.

Morgan McGuire has a really cool iphone app on graphics formulas and concepts.  It's The Graphics Codex

A friend and some others whom may or may not be anonymous (they can comment if they are willing to reveal themselves) have done a cool NPR app that is very nice but has a nice side effect I think is killer: it makes blurry photos look just fine.   It's called Glaze

My ex-student Kurt Zimmerman has done a fortune telling app that finally gets a platonic solid into a real program: the Lucky Fortune 9 Ball.   The "feature" of this program is that you can either let the yes/no answers be random, or control them yourself by finger placement.  Perhaps that is a rebellion from his Monte Carlo work?   Although I have not even seen the code for this app, I did buy piece of it from Kurt as I think cheating is "in".

Other ex-students the Gooches have some NPR apps as well, one of which is on free promotion today-- get it!   Both PencilFX and ToonPaint are described at their web site

If anyone else has done an app, put it in the comments.  I am wondering if it's a trend. 

Saturday, May 12, 2012

A call for a meta-H index



A sad aspect of modern academics is rankings matter. For computer science departments the main ranking is from the NRC, and as the CRA has pointed out severe methodological problems. John Regehr and I a few years ago did an informal pilot of ranking departments by citations and our impression is that this worked at least as well as any current ranking method, and was almost fully automatable. Google scholar has recently added some new features that will allow such a ranking to be EASY. For example, here is Pat Hanrahan's page. Note google is computing his h-index which for Pat is 61. This means pat has 61 papers with 61 or more citations, but he does not have 62 papers with 62 or more citations. This is a more stable to outliers than citation counts, and is more robust from error. The problem of course is that being author on a paper doesn't mean you contributed much (or in some cases anything!). For example, perhaps my most cited paper is "Color transfer between images." I am pretty sure I read it, and may have even made some suggestions, but all the creative ideas and coding were by the other guys. I know of some CVs where all of the papers are of this form. I also know many authors that have no papers like that on their CV. Trying to sort that out would be a lovely PhD data mining dissertation topic.

But from that highly imperfect individual data, the related "meta-h index" for an organization does measure something I think is likely more meaningful. The meta-h index for a department is 30 if there are 30 group members with an h-index of 30 or more. One key advantage of that index is that emerging universities outside of the traditional big name universities can quickly get recognition. I imagine we'd see some real players in South America and Asia under this measure that might not show up for decades under the NRC measures.

Further, one could rank research groups, colleges, and whole universities or companies this way. It wouldn't be perfect, but would encourage papers that would ultimately get lots of citations, rather than encouraging papers that follow today's fashions. This would be a good side-effect, and would help bring about the much-needed demise of paywall publications.

I sent this suggestion to google. Please join in and send them more. It would be easy for them, and would encourage authors to enter their information, so would be good for google too.