Found this YouTube channel through Day. Vihart posts about fun things like spirals, knot theory, and fractals. Check it out! More »
The world is complicated. More »
Meh, I’m definitely not the target audience for this. I regularly hook up my Blackbook to my TV, connect a wireless keyboard and mouse, and I’m good to go. Hulu, Netflix, YouTube, etc. are all at my fingertips. The intriguing part, though, is that some TVs are going to be built with Google TV. So essentially these TVs become internet devices without having to attach a computer. That’s a pretty neat idea, especially for the non-tech-savvy. The Google TV box, on the other hand, seems like it’s just going to be another cuboid to silently drain energy. Why buy another box when you could hook up a computer to your tv?
School’s out! So why am I writing about the Hough transform again? Well, in my previous post, I just kind of took the Hough transform of a few gifs and didn’t really think twice about it. Now that my paper is written, I can actually explain just what’s going on.
The standard Hough transform finds lines within an image. It does this by taking a binary edge image (more on this in a future post), and transforming the points into “Hough-space”. Each point of the edge image is turned into a sinusoid in Hough-space. Points that tend to form a line will create a “knot” in Hough-space, while points that don’t line up have no such knot.
The two figures above (from Wikipedia) depict how a point in real-space (that is, a point within the image) is transformed into a sinusoid in Hough-space. Multiple co-linear points will create a knot in Hough-space seen in the second figure.
The brightness of a pixel in Hough-space denotes the relative “strength” of a knot. Thus, in the YouTube video above, one can see the bright point migrate from the right to the left as the bar spins in the GIF.
So how would you use the Hough transform? Well, one can use the Standard Hough Transform (which finds lines) and then a threshold on Hough-space to determine whether or not a line exists. The Hough transform itself has been generalized to find other shapes like circles or ellipses. There’s even a version where you can create your own shape that you would like to find. This generality is why the Hough transform is used quite often in computer vision (as I’m told).
As promised, a review of Andy McKee’s Joyland. In it, Andy has branched out from his normal solo guitar to include other instrumentation like the strings in the titular song. Always calming, ever relaxing, this album stays true to the feel of previous releases like Art of Motion and Games of Gnomeria. There are three stand out songs I’d like to mention, the first “Everybody Wants to Rule the World”, I already mentioned in a previous post. The second, “For Now”, is such an awesome way to end the album. There isn’t singing in any of Andy’s songs, but the melody really just sings. The final mention, Hunter’s Moon, is one of those songs, much like the song Drifting, that needs to be seen, as well as heard. And thus we end this blog post with the YouTube video of “Hunter’s Moon”.
Yesterday’s post about the continuum was really to just give a little background. I bought Black Clouds and Silver Linings, Dream Theater‘s newest album earlier, and it’s probably my favorite album of the year. There’s one solo, however, in “A Rite of Passage” that I just couldn’t figure out. It’s distinctly a Rudess solo because it’s just out there, but it wasn’t a regular keyboard solo or the continuum. So yesterday I had stumbled upon Rudess plugging Bebot for the iPhone. It’s an app much like the continuum in that you can slide around and play notes. Then, I found this video of the Rite of Passage solo section. Blew my mind.
I really really wish I had seen Dream Theater when they came around my area. All of the members are simply the best at what they do. In school, one of my lab partners turned me on to them. At first, I just brushed them off, but on a whim, I downloaded Metropolis Part 2: Scenes From a Memory and my mind was blown. At the time of this post I’ve scrobbled over 3,800 Dream Theater plays on Last.fm.
The picture above is of Jordan Rudess, Dream Theater’s keyboardist. It’s a blurry pic, but it was taken with my cell phone as it was on the door of Lippold Haken, a professor at U of I. Haken created the continuum fingerboard, a midi controller with a smooth surface on which you can slide your fingers. The instrument tracks your x (the key, or in between keys), y (front and back), and z (pressure) and you map that to the midi output. It’s a fantastic instrument, and you can see it in action in the YouTube clip below.