Category Archives: Misc

Greenscreen / Chromakey On The Mac

Before and After

Before and After

A work colleague asked about creating chromakey / green screen images the other day. The wanted to use their Mac computer to superimpose pictures of students on notable Chicago locations.

My quick-and-dirty suggestions were:

  • Photo Booth (the easiest, most appropriate solution from my perspective)
    • The downside to using Photo Booth is that it crashes on my laptop due to my installation of a Bluetooth webcam.
  • iMovie (a bit of a hack, but the process within iMovie is extremely easy)

Another colleague suggested using Photoshop. This tutorial clearly outlines the process. The above example only took a few minutes to create – I did not follow the tutorial fully to the end (hue saturation) which would have removed the green fringing.

Another option would be to use Veescope on iPad.


For the first time in quite a few years I have a Windows PC (Surface Pro) at home, so I thought I would check out a few PC games. Nothing too taxing on the tablet, the Surface is not really a games machine. As luck would have it, Steam was having a sale. I now have a mini-library of older games to play:

  • Final Fantasy VII
  • Half-Life
  • Half-Life 2
  • Portal

Video Mode Change Failure

Unfortunately Half-Life refuses to play on the Surface Pro, with this error message:

The game has detected that the previous attempt to start in OpenGL video mode failed. The game will run in software mode.

Solutions on the Web suggest changing the Set Launch Options:

-software , -OpenGL, did not work for me (the game ran, but in a unusably small window).

-w 640 -h 480 allowed me run the game in a usable window.


Aha, now I have a playable game

-w 1024 -h 768 allowed me run the game in a better window.


This isn’t going to work…

I believe the screen dimensions of the Surface Pro are 1920 x 1080, so I gave that a try:

-w 1920 -h 1080

However, that resulted in a window that exceeded the bounds of the display. For the moment I will stick with XGA.

Next, getting a suitable joystick/gamepad…

Resuscitating (and repurposing) the old Nokia N900

Nokia N900

Nokia N900

I migrated to an Apple iPhone 5 a while back. Even though the ‘phone is lacking a keyboard (which my old Nokia N900 had) I am fairly happy with the device. However,  I sort of need for a portable speaker, and rather than buy a Jawbone JAMBOX (or equivalent) I think I can repurpose the N900.

Over on Sabrog has a useful piece of script for activating the earphone socket as a line-in:

Speaker ON

amixer -c0 set PCM 100%
amixer -c0 set 'Right PGA Bypass Mixer HP Switc' on
amixer -c0 set 'Left PGA Bypass Mixer HP' on
amixer -c0 set 'Left PGA Mixer Line1L' on
amixer -c0 set 'Left PGA Mixer Line2L' on
amixer -c0 set 'HP PGA Bypass' 100%
amixer -c0 set 'Speaker Function' On
echo "Speaker is ON"

Speaker OFF

amixer -c0 set PCM 100%
amixer -c0 set 'Right PGA Bypass Mixer HP Switc' off
amixer -c0 set 'Left PGA Bypass Mixer HP' off
amixer -c0 set 'Left PGA Mixer Line1L' off
amixer -c0 set 'Left PGA Mixer Line2L' off
amixer -c0 set 'HP PGA Bypass' 0%
echo "Speaker is OFF"

Thanks Sabrog!


Instagram: A Half-Year Resolution

The Power of Habit

I recently finished reading Charles Duhigg’s rather excellent book “The Power of Habit.” The book explores why habits form, and what can be done to change them. It is a very entertaining and interesting read. Reading the book, I started to think about some of my habits – which ones I wanted to change, which ones I could change, how one habit change might effect other habit changes.

One experiment that I have decided to begin is taking a daily photograph. The plan from here on is to take one photograph a day, and then post it to the Internet. Instagram is the weapon of choice here, and I will see how taking that picture changes other habits and behavior. The pictures should show up on the site here, but they will also appear on: