Shawn Lankton Online

After spending about an hour fighting with PIL (Python Imaging Library) and trying to get it to install properly with all of its dependencies I discovered that some wonderful person posted a ready-made pil installer for osx. This worked like a charm. First try. No problems.

God I love it when people do stuff like this. Now, hang on as I learn to do image processing with Python on my mac.

Since I moved to mac, one of the things that I miss the most is the behavior of the alt-tab menu. Sure, OSX has the apple-tab (or command-tab) menu, but it only cycles through open programs and not open windows. This means that if you minimize a window, you can’t get back to it without clicking on it on the dock.

Well no longer my friends! “Witch” is a great program that gives you alt-tab functionality in mac. “Witch” has a whole mess of options as well, so you can set it up to do lots of task-switching-related things. Furthermore, its free. Go grab it and start alt-tabbing through minimized windows again!

Now, if I could find a way to make the “maximize” button in OSX actually maximize a window instead of just making it a little wider we’d be in business!

One of the nice features about my mac is that you can hold control and use the scroll feature to zoom into the screen. This is handy for delicate computer graphics and reading fine print, but what I use it for the most is zooming in on web-videos that won’t go full-screen. Sure, you could click the video, open the YouTube page, and *then* full-screen, but that’s a lot of work!

The problem is that when you zoom on the screen, the image of your mouse zooms as well. This means that right smack in the middle of your freshly-zoomed video is a giant arrow! How do you get rid of the cursor? You can hide the cursor really simply, here’s how:

1. press Command+L (AKA Apple+L)
2. press the down arrow

This gives focus to the address bar, then pressing down hides the arrow cursor for a bar in the text box. Voila, enjoy your movie sans the arrow! Thanks to these guys where I found the answer.

(NOTE: Apple+L may only work in Firefox and Safari.)

Mac User? Try it out on this video!

First off, quicksilver is an amazing tool. In fact, this program alone is worth switching to mac for. This post had the video below from the creator (as well as some great get-to-know quicksilver links). The creator has some seriously good ideas about how software and interfacing should work…. and guess what? He works for Google now!

Really, check out this post too.

The GIMP has long been a rival for Photoshop. It’s free, open source, and has nearly the same feature set! However, I being a staunch old Photoshop user never seriously considered GIMP because I was too attached to the location of the buttons, menus, and keyboard shortcuts and didn’t want to learn a new program.

Thanks to GIMPShop, I don’t have to learn anything! These guys took the GIMP and re-tooled it so that it looks and feels a lot like Photoshop. Since the feature set is almost identical I’m switching. (It also runs great on my mac!) Get more info and download it for yourself from here:

• gimpshop.net (with download links)
• Great post about GIMPshop
• Wikipedia article about GIMPShop

If you do computer vision research (as some of you may). Or any other type of research for that matter… Its a good idea to make nice videos of the results that you obtain. This is a simple disaster-proof way of demoing your work. I’ve been doing this quite a bit lately (as a result of all the video tracking work). I’ve come up with some tips, tricks, and tools that will help out the aspiring video-creator (who uses Matlab and Linux… otherwise you’re out of luck).

Personally, I find Matlab’s built-in avi code terrible. It’s just bad. Instead, I prefer to make figures that show what I want to show on each frame, save those out, and then compile them into a movie later. This seems to be the nicest command to save the frames out:

>>for i=1:last_frame
>> %% code to create the frame in a figure
>> f = getframe;
>> imwrite(f.cdata, sprintf(’./video/%04d.png’,i));
>>end

This should leave you with a directory full of .png files. From here you have to assemble these into a movie. This is a fantastic script called mkmpeg4 (download). The way to run it is as such (by the way, this only works in Linux with mplayer installed)

$mkmpeg4 -o output.avi -f 30 `ls *.png`
$mplayer output.avi

Note the ` quotation marks as opposed to your typical ‘ marks. This makes compressed videos that look good and will still play on Linux, Windows, and Mac. (Also, they work in PowerPoint). One final tip. If you want to go the other way; take a video and convert it to frames, here’s how:

$mplayer -vo png movie_to_unpack.avi

If you video file is interlaced (looks good in a player, extracted images look bad), try this instead:

$mplayer -nosound -vf pp=ci -vo png:z=0 movie_to_unpack.avi

Happy Matlab Video-ing. Feel free to post your own tips or correct mine in the comments.

I have officially joined the “I have a laptop” club. And what’s more, I joined a subset of that club known as the “I have an Apple laptop” club. Yes its true… I purchased a MacBook recently and have been enjoying it thoroughly!
To the apple users of the world, here are some of the tips and tricks I’ve accumulated so far:
* Get and use Quicksilver
* Get and use Virtuedesktops
* Get iRed Lite if you want to do lots of cool stuff with your remote (besides use “FrontRow”)
* Become one with keyboard shortcuts
* Map your Caps Lock key to be Control (makes the above easier)

Thats about all for now. Presumeably, now that I have a Mac, I’ll be much more creative and ‘cool.’ (Didn’t you see the commercials?!) So be expecting some art, movies, cartoons, etc… who knows?!