brainwagon

Various projects that I’ve worked on rely on building efficient hash tables for looking up, well, all sorts of stuff (wow, that was vague). Say, storing transposition table entries in my checkers program. Cuckoo hashing is a way of resolving hash table collisions. Here are some references: My Biased Coin: Cuckoo Hashing, Theory and Practice […]

I’ve bitched before about CSI and their use of “video enhancement” to read displays and the like using low resolution security cameras reflecting off objects. It’s interesting to see what is actually possible using this basic idea though. Link courtesy of Bruce Schneier’s security blog: Schneier on Security: Spying on Computer Monitors Off Reflective Objects

While trying to find out if Python included some built-in capabilities for dealing with BCD numbers (it appears not) I encountered this rather interesting page about decimal arithmetic. General Decimal Arithmetic

I do like programming “for fun”, and this includes writing programs that, well, have been written hundreds of times before, but which I never have bothered doing. Often, this is just an exercise: freely available libraries often exist for many tasks which are considerably better than anything that I write. Nevertheless, I don’t consider it […]

Well, my excursion into FFT multiplication the other day left me with some more interesting questions, including trying to find out more information about the integer version of the FFT called the NTT (number theoretic transform). Instead of computing the transform to an orthogonal basis consisting of the complex roots of unity, the NTT transforms […]

Tom Duff recommended this blog for my perusal, and I filed it away. Today I discovered that it was linking back to one of my more popular posts: the one in which Tom Duff talks a little bit about Duff’s device. But there’s a lot of good reasons to check it out. I found this […]

It’s 8:22AM, and I’m just waking up, checking my email and surveying my usual blogs with Google Reader. I don’t have time to explain why this link seems interesting, but if you are interested in random walks, computability or cellular automata, check out the following link. I haven’t had time to absorb it yet (and […]

This week I’m busy at work trying to complete dozens of SIGGRAPH sketch reviews, so it seems like an opportune time to present the usual link to  online copies of the SIGGRAPH 2006 Papers that have been accepted.  I haven’t had a chance to review these yet, but there is usually something good in this […]

There is a new security update for WordPress, which I’ve already installed without any serious mishap/problems. If you run WordPress, you might think about giving it an upgrade. [tags]Wordpress,Blogging,Security[/tags] Addendum: I’ve been having minor problems with the Dashboard in this release not displaying correctly.  I’m still trying to figure it out.

You might have noticed if you are a long time reader of this blog that I’m fascinated by codes and ciphers, particularly the kind that were developed before computers really came on the scene.   That’s why I’m finding the M4 Message Breaking Project interesting: they are attempting to break three two as yet unbroken code […]

Josh over at tinyscreenfuls is digging some of the fancy “pencil sketch” effects that the Mac can do with its internal camera.  Back in 1998, I experimented with writing some filters that did much the same, with some examples that I generated shown on the right.   Macintosh?  I don’t need no steekin’ Macintosh. 🙂 And […]

This is just completely nuts, an 8 bit computer constructed entirely from 12 volt relays. It consumes 12 amps at 13.5 volts (160 watts). Hilarious. [tags]Retrocomputing,Hacks[/tags]

Last night we had a screening of Hoodwinked, the new animated feature by director Cory Edwards and co-directed by Todd Edwards. It’s a retelling of the classic story of Little Red Riding Hood, and features the vocal talents of Glenn Close as Granny, Ann Hathaway as Red, James Belushi as the Woodsman, veteran voice over […]

Well, Steve is still up there, but the big news (as yet unreflected on the Apple website) is the announcement of a new Intel based iMac. It will apparently come in the same sizes and prices as previous G5 iMacs, but will use Intel’s new CoreDuo processor that was plugged by Intel so heavily at […]

Okay, I know this is an atrocity, but you might still find Recolored to be an interesting program for adding color to black and white images. You basically scribble hints into the image, and it propagates the color to nearby pixels that it determines should be the same color. At right, you can click and […]