Comments on: Optical illusion, mathematical illusion http://www.johndcook.com/blog/2009/06/24/optical-illusion/ The blog of John D. Cook Sat, 13 Mar 2010 14:22:54 -0500 http://wordpress.org/?v=2.8.4 hourly 1 By: John http://www.johndcook.com/blog/2009/06/24/optical-illusion/comment-page-1/#comment-19950 John Thu, 25 Jun 2009 19:10:04 +0000 http://www.johndcook.com/blog/?p=2541#comment-19950 Dave: Good point. I resized the original image, but I should have cropped it. I replaced my first image with a cropped version of the original. Dave: Good point. I resized the original image, but I should have cropped it. I replaced my first image with a cropped version of the original.

]]> By: Dave Richeson http://www.johndcook.com/blog/2009/06/24/optical-illusion/comment-page-1/#comment-19949 Dave Richeson Thu, 25 Jun 2009 19:07:35 +0000 http://www.johndcook.com/blog/?p=2541#comment-19949 That's a great analogy, John. Thanks for posting it. I'll have to remember it. The illusion is really neat too, but one thing that is interesting about the image that <b>you posted</b> is that if you zoom in you'll see that there are many more than three colors present! I don't know if you or your blog software made the image smaller, but in the process of doing so, the compression changed the colors of most of the pixels (the stripes are so thin that most of the pixels are on or near a boundary, so they combine the colors in some way). I posted a zoomed-in versions of the <a href="http://users.dickinson.edu/~richesod/images/illusionzoom.png" rel="nofollow">original image</a> (the one you linked to) and of <a href="http://users.dickinson.edu/~richesod/images/illusionzoom2.png" rel="nofollow">your compressed image</a> for you to see. That’s a great analogy, John. Thanks for posting it. I’ll have to remember it.

The illusion is really neat too, but one thing that is interesting about the image that you posted is that if you zoom in you’ll see that there are many more than three colors present! I don’t know if you or your blog software made the image smaller, but in the process of doing so, the compression changed the colors of most of the pixels (the stripes are so thin that most of the pixels are on or near a boundary, so they combine the colors in some way). I posted a zoomed-in versions of the original image (the one you linked to) and of your compressed image for you to see.

]]> By: Bill the Lizard http://www.johndcook.com/blog/2009/06/24/optical-illusion/comment-page-1/#comment-19883 Bill the Lizard Thu, 25 Jun 2009 02:22:23 +0000 http://www.johndcook.com/blog/?p=2541#comment-19883 I for one would like to hear that in the voice of Lt. Commander Data. I for one would like to hear that in the voice of Lt. Commander Data.

]]> By: John http://www.johndcook.com/blog/2009/06/24/optical-illusion/comment-page-1/#comment-19877 John Thu, 25 Jun 2009 00:18:24 +0000 http://www.johndcook.com/blog/?p=2541#comment-19877 The speech software doesn't read math expressions well, but it does a remarkable job on plain text. I like how it has natural inflection before punctuation. The speech software doesn’t read math expressions well, but it does a remarkable job on plain text. I like how it has natural inflection before punctuation.

]]> By: Sohail http://www.johndcook.com/blog/2009/06/24/optical-illusion/comment-page-1/#comment-19875 Sohail Wed, 24 Jun 2009 23:58:28 +0000 http://www.johndcook.com/blog/?p=2541#comment-19875 Wow, your blog audio is freaking good. Wow, your blog audio is freaking good.

]]> By: Sohail http://www.johndcook.com/blog/2009/06/24/optical-illusion/comment-page-1/#comment-19874 Sohail Wed, 24 Jun 2009 23:57:42 +0000 http://www.johndcook.com/blog/?p=2541#comment-19874 Cool! I can actually see it though if I squint and look at the top of the image. I see two shades of green though, not the same shade. Cool! I can actually see it though if I squint and look at the top of the image. I see two shades of green though, not the same shade.

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