Comments on: The blue and the green http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/ I am an astronomer, writer, and skeptic. I likes reality the way it is, and I aims to keep it that way. My real name is Phil Plait, and I run the Bad Astronomy blog. Mon, 13 Feb 2012 22:40:34 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Increíble pero cierto | Coolors http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-479944 Increíble pero cierto | Coolors Fri, 10 Feb 2012 16:34:20 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-479944 [...] sacado esta curiosidad del artículo Bad Astronomy , cuyo autor, Phil Plait explica este fenómeno de la siguiente manera: “La razón por la que se ve el mismo color como [...] [...] sacado esta curiosidad del artículo Bad Astronomy , cuyo autor, Phil Plait explica este fenómeno de la siguiente manera: “La razón por la que se ve el mismo color como [...]

]]> By: Friday Links (6-Jan-12) -- a Nadder! http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-464582 Friday Links (6-Jan-12) -- a Nadder! Fri, 06 Jan 2012 04:28:57 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-464582 [...] Mind-blowing optical illusion that shows how much our mind’s eye photoshops our colour perception. [...] [...] Mind-blowing optical illusion that shows how much our mind’s eye photoshops our colour perception. [...]

]]> By: Today’s Best Optical Illusion | Miscellaneous Heathen http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-453354 Today’s Best Optical Illusion | Miscellaneous Heathen Mon, 12 Dec 2011 20:44:10 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-453354 [...] are only two colors in this graphic. Really. This entry was posted in Weird by Chet. Bookmark the [...] [...] are only two colors in this graphic. Really. This entry was posted in Weird by Chet. Bookmark the [...]

]]> By: Today’s Best Optical Illusion | Miscellaneous Heathen http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-452522 Today’s Best Optical Illusion | Miscellaneous Heathen Sat, 10 Dec 2011 21:31:04 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-452522 [...] are only two colors in this graphic. Really. This entry was posted in Weird by admin. Bookmark the [...] [...] are only two colors in this graphic. Really. This entry was posted in Weird by admin. Bookmark the [...]

]]> By: Troxler’s Fading: Your Mind is About to Be Blown | The Sloan Blog http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-438374 Troxler’s Fading: Your Mind is About to Be Blown | The Sloan Blog Wed, 09 Nov 2011 22:32:45 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-438374 [...] a few weeks ago, everyone was sharing this awesome optical illusion image of a spiral of overlapping bands of what appeared to be purple, orange, blue, and green. [...] [...] a few weeks ago, everyone was sharing this awesome optical illusion image of a spiral of overlapping bands of what appeared to be purple, orange, blue, and green. [...]

]]> By: women are from Omicron Persei 7 and other Nice Guy stories the patriarchy wants you to believe « warrior-princess.org http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-434334 women are from Omicron Persei 7 and other Nice Guy stories the patriarchy wants you to believe « warrior-princess.org Sun, 30 Oct 2011 12:31:02 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-434334 [...] that are as difficult to see past as it is to convince yourself that the blue and the green of this image are actually the same color (they are). Let’s run them [...] [...] that are as difficult to see past as it is to convince yourself that the blue and the green of this image are actually the same color (they are). Let’s run them [...]

]]> By: Wicked cool optical illusion. « MJBDiver's Blog http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-426916 Wicked cool optical illusion. « MJBDiver's Blog Sun, 09 Oct 2011 06:14:27 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-426916 [...] it or not, the blue and green spirals are actually both the exact same color. Check out this page for an explanation. Share this:TwitterFacebookLike this:LikeBe the first to like this [...] [...] it or not, the blue and green spirals are actually both the exact same color. Check out this page for an explanation. Share this:TwitterFacebookLike this:LikeBe the first to like this [...]

]]> By: Breakfast briefing: Copycats and copyright | Richard Hartley http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-422413 Breakfast briefing: Copycats and copyright | Richard Hartley Mon, 26 Sep 2011 12:00:05 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-422413 [...] your mind with some optical illusions. No tricks this time, but just some stone cold classics: this mind-boggling colour illusion, and the spinning woman. Why not leave your best suggestions in the comments?You can follow our [...] [...] your mind with some optical illusions. No tricks this time, but just some stone cold classics: this mind-boggling colour illusion, and the spinning woman. Why not leave your best suggestions in the comments?You can follow our [...]

]]> By: edzonrapisora http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-421219 edzonrapisora Fri, 23 Sep 2011 10:35:21 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-421219 i always use this as an example when teaching color grading and correction. this is why i always tell people to never use their naked eye alone when color correcting photos and videos. always use visual reference for viewing color like the historgram, RGB parade, vector scope, etc. to judge your adjustments. even proud people who say that their "eyes are sensitive to color" should see this and know better after on. i always use this as an example when teaching color grading and correction.

this is why i always tell people to never use their naked eye alone when color correcting photos and videos. always use visual reference for viewing color like the historgram, RGB parade, vector scope, etc. to judge your adjustments.

even proud people who say that their “eyes are sensitive to color” should see this and know better after on.

]]> By: The “Benham’s Top” Illusion: What Colour Do You See? | Onelargeprawn http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-416982 The “Benham’s Top” Illusion: What Colour Do You See? | Onelargeprawn Tue, 13 Sep 2011 15:02:36 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-416982 [...] the blue in this spiral are actually the same color. As interesting as that is (the explanation is here), one of the commenters submitted another illusion that caught my [...] [...] the blue in this spiral are actually the same color. As interesting as that is (the explanation is here), one of the commenters submitted another illusion that caught my [...]

]]> By: Josh http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-393073 Josh Fri, 01 Jul 2011 04:38:32 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-393073 It's interesting, but even when I look at this pattern from far away without my glasses (fuzzy!), the blue/green illusion remains..meaning it's not the brain "assembling" the colors from the lines themselves, but just the collective mixed color reaching my retina from each general area of the image..meaning it's a physical phenomenon, and not a neurological one It’s interesting, but even when I look at this pattern from far away without my glasses (fuzzy!), the blue/green illusion remains..meaning it’s not the brain “assembling” the colors from the lines themselves, but just the collective mixed color reaching my retina from each general area of the image..meaning it’s a physical phenomenon, and not a neurological one

]]> By: sam http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-9/#comment-391864 sam Sun, 26 Jun 2011 10:17:02 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-391864 crazy, i played around with the image in photoshop (yes the same color) and it its the same with any color...using black makes one spiral look blue, using white, one looks yellow. You can try it by in the select color range and then adjusting lightness, saturation and hue..impressive crazy, i played around with the image in photoshop (yes the same color) and it its the same with any color…using black makes one spiral look blue, using white, one looks yellow. You can try it by in the select color range and then adjusting lightness, saturation and hue..impressive

]]> By: خداع بصري: المخ مرات يفهم الألوان غلط | Kumail+ http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-390120 خداع بصري: المخ مرات يفهم الألوان غلط | Kumail+ Sat, 18 Jun 2011 19:08:22 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-390120 [...] Discover Magazine   Tweet  eyes, illusion  |&nbsp عيارة اليهال لما يطيحون [...] [...] Discover Magazine   Tweet  eyes, illusion  |&nbsp عيارة اليهال لما يطيحون [...]

]]> By: » Characters, Green and Language Psychology Pig http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-389915 » Characters, Green and Language Psychology Pig Fri, 17 Jun 2011 19:19:07 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-389915 [...] The blue and the green | Bad Astronomy | Discover Magazine [...] [...] The blue and the green | Bad Astronomy | Discover Magazine [...]

]]> By: Anthony http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-389485 Anthony Wed, 15 Jun 2011 23:57:02 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-389485 (continued from last comment) There has been an ill-conceived attempt to smooth out the dithering at the tonal boundaries of the image, which in its original form was quite jagged (evidenced by the detailed view below the large image). This would have introduced anti-aliasing errors, bleeding in colours across tonal boundaries. The goal of digital image processing is to replicate human visual performance. In this instance it has also replicated a human visual anomoly, even when the author sought to illustrate the opposite. (continued from last comment)
There has been an ill-conceived attempt to smooth out the dithering at the tonal boundaries of the image, which in its original form was quite jagged (evidenced by the detailed view below the large image). This would have introduced anti-aliasing errors, bleeding in colours across tonal boundaries.
The goal of digital image processing is to replicate human visual performance. In this instance it has also replicated a human visual anomoly, even when the author sought to illustrate the opposite.

]]> By: Anthony http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-389481 Anthony Wed, 15 Jun 2011 23:30:16 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-389481 Following-on from my last comment (June 13th, 2011), after more thought I've concluded that the errors in this image aren't jpeg artifacts, but anti-aliasing errors. I’ve looked at this illusion on a couple of websites and both have a similar problem. Apparently, in 2009, most commenters remarked that the “blue” spirals and the “green” spirals were perfect matches. But now, in 2011, the image of the illusion is so full of anti-aliasing errors that these supposedly identical colours are in fact different. Try it yourself before you reflexively deny it. Copy the source file out to an editor and sample the “blues” and “greens” at a high magnification. Could the web-host have reprocessed the image files to reduce the page size, unwittingly introducing errors? Following-on from my last comment (June 13th, 2011), after more thought I’ve concluded that the errors in this image aren’t jpeg artifacts, but anti-aliasing errors.

I’ve looked at this illusion on a couple of websites and both have a similar problem. Apparently, in 2009, most commenters remarked that the “blue” spirals and the “green” spirals were perfect matches. But now, in 2011, the image of the illusion is so full of anti-aliasing errors that these supposedly identical colours are in fact different. Try it yourself before you reflexively deny it. Copy the source file out to an editor and sample the “blues” and “greens” at a high magnification.

Could the web-host have reprocessed the image files to reduce the page size, unwittingly introducing errors?

]]> By: Anthony http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-389064 Anthony Mon, 13 Jun 2011 23:44:05 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-389064 I'm with Devin here. This image appears to have been saved at least once, perhaps more times, as a jpeg and so is full of jpeg artifacts that are doing just what the eye does and what the description claims is illusory, distorting colour and brightness at tonal boundaries. It's not too bad at the outside where the blocks of colour are large so the distorted values are a less significant part of the image, but towards the centre the distorted values become a large portion of each colour block. The RGB values near the centre are approx. 0.155.190 in the "green" blocks and from approx. 0.155.100 to 0.155.120 in the "blue" blocks. This image needs to be replaced with a clean version that hasn't had lossy compression. I’m with Devin here. This image appears to have been saved at least once, perhaps more times, as a jpeg and so is full of jpeg artifacts that are doing just what the eye does and what the description claims is illusory, distorting colour and brightness at tonal boundaries. It’s not too bad at the outside where the blocks of colour are large so the distorted values are a less significant part of the image, but towards the centre the distorted values become a large portion of each colour block. The RGB values near the centre are approx. 0.155.190 in the “green” blocks and from approx. 0.155.100 to 0.155.120 in the “blue” blocks. This image needs to be replaced with a clean version that hasn’t had lossy compression.

]]> By: Devin http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-387688 Devin Wed, 08 Jun 2011 06:50:42 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-387688 Well, I took this .png file into paint AND into photoshop, and there are hundreds of colors in the image. There is a fuzzy but definitely real outline to both the blue and green sections, so I don't know what image you guys are looking at. I've found versions of this spiral online which are legitimately composed of only three colors, and they're convincing, but this version has been botched. Even using your inkdropper in paint will confirm it. Zoom in on the borders and try dropping the color onto the other spiral. Not even close. Well, I took this .png file into paint AND into photoshop, and there are hundreds of colors in the image. There is a fuzzy but definitely real outline to both the blue and green sections, so I don’t know what image you guys are looking at. I’ve found versions of this spiral online which are legitimately composed of only three colors, and they’re convincing, but this version has been botched. Even using your inkdropper in paint will confirm it. Zoom in on the borders and try dropping the color onto the other spiral. Not even close.

]]> By: Adam F http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-387271 Adam F Sun, 05 Jun 2011 19:02:42 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-387271 I've got a bit of a problem with the idea that this image demonstrates that the pre-processing our brain does generally makes us see the world in a less accurate way. The problem here is that this image presents the eyes with an unnatural and intentionally confusing arrangement of colors. In real life, our brain processes the images so that objects which are _actually_ the same color appear to be the same color, despite different lighting conditions causing different wavelengths and intensities of photons to actually hit our eyes. If it didn't do these sorts of things, you might, eg, have trouble finding your car if you parked it in the sun and came back looking for it in the shade, because it would falsely appear to be a different color. TL;DR In most instances, the same things which make you see this image inaccurately help you see the world more accurately. I’ve got a bit of a problem with the idea that this image demonstrates that the pre-processing our brain does generally makes us see the world in a less accurate way. The problem here is that this image presents the eyes with an unnatural and intentionally confusing arrangement of colors. In real life, our brain processes the images so that objects which are _actually_ the same color appear to be the same color, despite different lighting conditions causing different wavelengths and intensities of photons to actually hit our eyes. If it didn’t do these sorts of things, you might, eg, have trouble finding your car if you parked it in the sun and came back looking for it in the shade, because it would falsely appear to be a different color.

TL;DR
In most instances, the same things which make you see this image inaccurately help you see the world more accurately.

]]> By: links for 2011-05-30 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-385915 links for 2011-05-30 Tue, 31 May 2011 00:23:14 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-385915 [...] The blue and the green | Bad Astronomy | Discover Magazine [...] [...] The blue and the green | Bad Astronomy | Discover Magazine [...]

]]> By: Lateral Inhibition, Vision and Optical Illusion’s Explained | Ravall http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-385832 Lateral Inhibition, Vision and Optical Illusion’s Explained | Ravall Mon, 30 May 2011 06:47:29 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-385832 [...] over at Discovermagazine’s blog post. Unfortunately, not a single individual on Reddit or Discovermaganize was able to name this infamous effect (let alone explain it). As a result, having taken Sensory and [...] [...] over at Discovermagazine’s blog post. Unfortunately, not a single individual on Reddit or Discovermaganize was able to name this infamous effect (let alone explain it). As a result, having taken Sensory and [...]

]]> By: manthanr http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-385831 manthanr Mon, 30 May 2011 06:44:54 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-385831 I just wrote an article on optical illusions where I attempt to explain the image above using lateral inhibition. Feel free to check it out as I'm sure it relates to many of your interests. the article covers: simultaneous contrast and hermann grids. The link is: http://www.goo.gl/IbNOk Cheers! I just wrote an article on optical illusions where I attempt to explain the image above using lateral inhibition. Feel free to check it out as I’m sure it relates to many of your interests. the article covers: simultaneous contrast and hermann grids. The link is: http://www.goo.gl/IbNOk

Cheers!

]]> By: FactorZero | Alucinante: El Efecto Optico Verde-Azul http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-385793 FactorZero | Alucinante: El Efecto Optico Verde-Azul Sun, 29 May 2011 22:11:26 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-385793 [...] palabras de Phil Plait de Bad Astronomy (que es donde lo ví) y que explicó cómo funciona… La razón por la que se ven [...] [...] palabras de Phil Plait de Bad Astronomy (que es donde lo ví) y que explicó cómo funciona… La razón por la que se ven [...]

]]> By: charles http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-385732 charles Sun, 29 May 2011 11:15:12 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-385732 Seurat employed this to good effect. Seurat employed this to good effect.

]]> By: The blue and the green | Bad Astronomy | Tremendous optical illusion « Adverstuff http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/comment-page-8/#comment-385643 The blue and the green | Bad Astronomy | Tremendous optical illusion « Adverstuff Sun, 29 May 2011 06:25:18 +0000 http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/#comment-385643 [...] May 29, 2011 by Patrick Berry Leave a Comment via blogs.discovermagazine.com [...] [...] May 29, 2011 by Patrick Berry Leave a Comment via blogs.discovermagazine.com [...]

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