Monroe or Einstein? Instant eyesight check. | Hacker News Reader

Monroe or Einstein? Instant eyesight check.

lifehacker.com

212 pointsbtilly50 comments

For the curious, I believe this works by doing a Fourier decomposition of both images. Then the composite image is produced by taking the low-frequency components from Monroe, and high-frequency components from Einstein. This way the "details" of the image look like Einstein, but the "overall" image looks more like Monroe.

Not to take this off-topic, but I never understood how an image can be converted into a Fourier series. It always made sense for waves, but images?

Think of a black and white image like a surface.

  image :: (R, R) -> R

Imagine the waveform of a sound wave - there is an amplitude for each point in time, which you can easily take a FT of. This waveform could also be, say, a vibrating guitar string at a fixed moment in time, in which case the units are amplitude vs. distance, but it is still just a function that you can take a FT transform of (now the "frequency" domain is the inverse of distance rather than the inverse of time, but it still works). An image is just a function of amplitude vs. distance, though there are 2 distance variables since an image is 2-dimensional, but the idea is the same, and the Fourier Transform is still defined for functions of 2 or more variables. In a color jpeg, I believe this is done individually for red, blue, and green, and the point at which you cut off the infinite series of Fourier coefficients determines image quality.

That said, this picture is awesome! I've never seen it done before.

Here's a thorough explanation, with illustrations.

http://www.hackerfactor.com/blog/index.php?/archives/440-The...

I learnt fourier transforms as something done to 2D images before I learnt any other applications, so I can draw the FT of a simple image by hand, but I really struggle getting my head around other applications :(

Images are just signals as a function of 2D space. So you can use the 2d FFT: http://fourier.eng.hmc.edu/e101/lectures/Image_Processing/no...

Another idea to grok: a checkerboard pattern image where every other pixel row and column are alternating full black and full white represents the "highest frequency" image possible at that sample rate (pixel density). This is the 2d equivalent of an alternating sinusoid +1,-1,+1,-1, etc

Please heed this warning. I didn't get an eye exam til my last semester in college.

Turns out, I've always needed glasses - and the reason studying was such a pain was because I was really straining my eyes. I always wondered how some people could study all day while I'd max out at 3-4 hours.

I got glasses and my last semester grades were quite good - please get your vision checked!

I've had glasses for most of my life, but had a similar problem studying. Recently found out I have convergence insufficiency, which rarely gets diagnosed. So even if you have glasses you might want to get a more comprehensive eye exam :)

EDIT: Also, this image makes me queasy.

I'm 3 years into a 5 year degree, and just got glasses last month. I'd gotten annual eye exams, which came out marginal, but the difference just didn't seem like enough to justify the expense and hassle.

Now, I can't believe what I was missing out on. You're right, eye strain really does make a difference to your ability to do work.

I experienced the same thing ... here's another test from personal experience ... if you look at a leafy tree and it looks like a brown stick with a green ball on top ... your vision is bad!

I know that sounds ridiculously obvious - but when your eyesight gets progressively worse, you simply don't realise how degraded it has become. I distinctly remember the first time I got glasses, walked outside and was amazed I could see individual leaves on the tree! It was like I had upgraded to a HD TV!

Same here. I had difficulties not to cry the first time I put my glasses because I found everything was so wonderful!

If you find yourself newly in need of glasses while going through the social crucible that is high school, consider jumping straight to contact lenses. Might not be for everyone, but it's something that I wish I'd done.

Glasses on: Einstein. Glasses off: Monroe.

So that's pretty cool. Of course, by the time I can see Marilyn, even the headline under the photograph is already blurred past recognition. If I squint so I can read the text, I can make out that it's actually Albert.

So, more of a cool face hack than a real utility.

Edit from below, for people who aren't nearsighted: Close one eye, put your thumb on the screen just under the image, and focus on your thumb as you draw it back towards your face. You can see Albert change into (blurry) Marilyn before your very eye!

Here's the paper detailing the process: http://cvcl.mit.edu/hybrid/OlivaTorralb_Hybrid_Siggraph06.pd...

[1] http://en.wikipedia.org/wiki/Hybrid_image

I remember reading this a few years back. The effect is actually really easy to recreate in photoshop from two photos. Our college magazine at the time was running an issue on the incoming student union committee so I knocked up a "double-image" for each position and wrote a short piece about the paper. People loved it.

Simply downscaling the image will also turn Einstein into Monroe, which demonstrates that it's non-trivial to even define what correct downscaling means.

You may be interested in this article that was on hacker news a while ago: http://www.4p8.com/eric.brasseur/gamma.html

And the hacker news discussion: http://news.ycombinator.com/item?id=1523991

I can't see Monroe no matter how hard I squint, or how far back I am. Although, maybe this room isn't big enough... How far back are we supposed to go? Or did I get trolled?

No, it's there. If you blur your vision by squinting you should see it - slightly crossing my eyes while squinting helped.

I can see Einstein normally though. Basically, the blurrier the image looks to you, the more like Monroe it will look.

I backed away from my laptop by about ten feet, at about a 45 degree angle, while sitting down. I was startled how much it was, at that distance and angle, clearly a picture of Marilyn Monroe.

Try making the image smaller. I don't have a lot of room in front of my monitor either, but by shrinking it down and scooting my chair back I could start to see her. It wasn't perfect though, it sort of looked like Marilyn Monroe crossed with a death's head.

Try closing one eye, putting your thumb on the screen just under the image, and focusing on your thumb as you draw it back towards your face. You can see Albert change into Marilyn before your very eye!

(That's what it's like for nearsighted people all the time. With glasses on, I can roughly simulate the blurriness of no glasses by focusing on my thumb about six inches from my face, with the image about two feet away.)

Works like a charm!

Not for me :-(. I see Einstein no matter what I do. I've never in my life been able to resolve stereograms, either.

There is a sidebar on the right hand side of the page that lists the top stories, and it has a smaller version of the image. I was able to see Marilyn in that one without much effort.

I backed up about 5 meters, closed one eye, and squinted the other really hard while focusing on one point.

Someone has one of these printed out at my grad lab. I can only see Marilyn from a very long way away. You might have to print it out.

Can you see where she should be? Even when looking at Einstein I can see where her eyebrows and such are hiding

I had to back up about 15 or 20 feet before I recognized Monroe. FWIW - I've got LASIK corrected vision.

I haven't had an eye exam in over a decade but I think that my vision was around 20/20 and I know that my grandfather had better than 20/20. This is probably about right though. I paced off 15 steps until I was about a yard from my monitor from where the picture was clearly Marilyn.

The tragedy of being really near-sighted: I see Einstein with glasses on and nothing/only blurry colors (whole page) with glasses off.

Well that makes you fortunate in one regard because you absolutely know you are near-sighted!

This test would have helped those like me. I'm near-sighted but not too bad. I can't really read text well from afar and didn't have glasses until 8th grade though I apparently needed them for some time. I always say at the front of the class because I just assumed text on the blackboard was not visible from the back for everyone.

Figuring out that I needed glasses opened my eyes, so to speak.

My story is similar. I never had problems with the concepts taught in maths/physics/etc classes but always seemed to get the questions on the blackboard wrong as I just couldn't see the writing properly. I got an eye exam around the 8th grade & was diagnosed as near sighted but before then I just thought the world was blurry and that everyone saw things like that :)

With my left eye, I can't focus on objects closer than 12 inch.

With my right eye, I can't focus on objects further than 26 inch.

I have glasses to correct this, but without glasses I can comfortably use a computer at a 'sweet spot' distance of 18 inch ;-)

Doesn't Monroe with no first name mean James Monroe? Because of this I was really trying hard to see the president, all the more confused because I am nearsighted.

I think they mean Marilyn Monroe.

Doesn't work for me. I see Einstein both with glasses and without (Monroe only becomes apparent if I'm 3 feet away sans glasses). However, text becomes blurry with glasses off.

Same for me. I guess that just means I don't need glasses that badly. They still help prevent eyestrain though.

If you dont need glasses then I would not use them because they will only make you dependent on them.

There is a study which shows that spending more time outdoors and looking at far away objects will help alleviate eye problems.

http://redsports.sg/2009/01/07/sunlight-myopia/

If you search around in google I think yoiu'll find a copy of the paper. Really worth a read.

Well no, I can see Einstein but letters are still blurry without glasses. Reading that way is a great way to get eyestrain and headaches.

Also your study is about children - nothing says that will reverse myopia in adults.

Another test: if you can read the text, you can see your computer screen.

(I sort of see Monroe out of my right eye with my glasses off. But the text is so far gone at that point that I would have no hope of reading why I'm looking at a picture of Monroe with a mustache.)

A much larger version of this (and its explanation) is on display in the MIT museum.

I'm near sighted, have glasses - and the image looks the same with and without.

Marilyn or Einstein?

Einstein

looked over the top of my glasses and it changed instantly to Monroe. I would prefer they changed the text from short-sighted to near-sighted though.

I really must put on my glasses before kissing.

ooh its like one of those 3D posters. if you stare at it long enough and make your eyes blurry Marilyn emerges.

With my glasses it looks like Einstein.

Reply on news.ycombinator.com