Archive for the ‘Mac/OSX’ Category

PIL in OSX, The Easy Way

February 5th, 2008 3 comments

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.

Presentation from Quicksilver’s Creator

September 6th, 2007 No comments

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.

Categories: Mac/OSX, Tips Tags: ,


July 27th, 2007 No comments

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:

Categories: Mac/OSX, Tips Tags:

Videos in Matlab and Linux

April 23rd, 2007 2 comments

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));

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.

Categories: Mac/OSX, Matlab Tags: , ,