Sunday, September 29, 2002

Optical Illusion

Optical illusions have always amused me and this is a good one. I read the text and understood exactly what the point was, but could not believe that the statement was actually true -- could those two squares actually be the same shade of gray?

Fortunately, Cocoa apps all include a very nice color panel that includes a little "magnifying glass" that allows you to pick a color from any pixel on the screen. That combined with the RGB mode that gives the raw RGB values as numbers between 1 and 255 confirmed that, yes, in fact, my brain had been fooled most thoroughly by that image.


I found the optical illusion via Lindsay Marshall's wonderful Bifurcated Rivets blog. If you are visiting Rivets for the first time, I would suggest doing so when you have a bit of spare time as it is pretty much guaranteed you will run across a plethora of interesting things that you have not seen before.
11:36:16 PM    

The documentation for mentions that all UserLand supplied templates include this macro. That ain't true -- the Movable Type derived templates do not.

Oops. At least it is easy enough to add.
12:26:14 PM