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Show HN: The text disappears when you screenshot it

unscreenshottable.vercel.app

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Re: Show HN: The text disappears when you screenshot it

#182

You can take TWO screenshots, moments apart, open in GIMP, paste one over the other and choose any one of these laying modes: Lighten, Screen, Addition, Darken, Multiply, Linear burn, Hard Mix, Difference, Exclusion, Subtract, Grain Extract, Grain Merge, or Luminance. https://ibb.co/DDQBJDKR

Bottom layer normal, second layer grain extract, top layer vivid light. This completely blacks out the whole area outside of the text.

Re: Show HN: The text disappears when you screenshot it

#184

You can take TWO screenshots, moments apart, open in GIMP, paste one over the other and choose any one of these laying modes: Lighten, Screen, Addition, Darken, Multiply, Linear burn, Hard Mix, Difference, Exclusion, Subtract, Grain Extract, Grain Merge, or Luminance. https://ibb.co/DDQBJDKR

> You can take TWO screenshots, moments apart, open in GIMP, paste one over the other and choose any one of these laying modes: You actually don't need any image editing skill. Here is a browser-only solution: 1. Take two screenshots. 2. Open these screenshots in two separate tabs on your browser. 3. Switch between tabs very, very quickly (use CTRL-Tab) Source: tested on Firefox

> use CTRL-Tab

Thank you forever for this, I ever used Ctrl-Page up/down for that.

Re: Show HN: The text disappears when you screenshot it

#185

Earlier quoted context omitted.

> You can take TWO screenshots, moments apart, open in GIMP, paste one over the other and choose any one of these laying modes: You actually don't need any image editing skill. Here is a browser-only solution: 1. Take two screenshots. 2. Open these screenshots in two separate tabs on your browser. 3. Switch between tabs very, very quickly (use CTRL-Tab) Source: tested on Firefox

You could also just record a video.

Hah, indeed, that was my first thought. This is clearly for fun though, it’s a cool project idea

Re: Show HN: The text disappears when you screenshot it

#186

I'm wondering. Can we also come up with something the other way around? Text you cannot read, unless you take a screenshot?

Maybe not exactly what you meant but it reminded me about the following: When one of our apple servers failed a decade ago and just vomitted out walls of error logs too fast to read anything,the apple support guy we called took his smartphone and made some photos to read and fix the error.

Re: Show HN: The text disappears when you screenshot it

#187

Earlier quoted context omitted.

That's reminiscent of a (possibly apocryphal?) method I once read about to get "clean" images of normally crowded public places - take multiple photos over time, then median each pixel. Never had the opportunity to try it myself, but I thought it sounded plausible as a way to get rid of transient "noise" from an otherwise static image.

That's a real method: https://digital-photography-school.com/taking-photos-in-busy... https://petapixel.com/2019/09/18/how-to-shoot-people-free-ph... But it only works well if the crowds move out of the way reasonably quickly. If we're taking about areas packed with people all blocking a certain area, and you need hours of shots, the change in ambient lighting over time will have negative effects on the end photo.

Ah, that's the method indeed! Thanks!

Re: Show HN: The text disappears when you screenshot it

#188

I'm wondering. Can we also come up with something the other way around? Text you cannot read, unless you take a screenshot?

If you have a very high enough refresh rate display, then yes: just flash alternatingly black-over-white and white-over-black text (i.e. invert it). We perceive essentially a low-pass filtered visual input (with limitations like neural firing rate), eventually it should appear as just uniform gray. Maybe adding some confusing elements might make it feasible at lower refresh rates.

Re: Show HN: The text disappears when you screenshot it

#189
post #163

Earlier quoted context omitted.

This was used in some early-20th-century astronomical setting, I think to detect supernovae. I can't find any documentation now, but my memory is that it was called "blink testing" or something similar, where one switched rapidly between two images of a star field so that changes due to a supernova would stand out.

https://en.m.wikipedia.org/wiki/Blink_comparator

That's it exactly! Thanks.

Re: Show HN: The text disappears when you screenshot it

#190
post #20

Another idea I had with this concept is to make an LLM-proof captcha. Maybe humans can detect the characters in the 'motion' itself, which could be unique to us? - The captcha would be generated like this on a headless browser, and recorded as a video, which is then served to the user. - We can make the background also move in random directions, to prevent just detecting which pixels are changing and drawing an outli…

I don't think we need more capable people thinking of silly captchas.

Why? stopping LLM crawlers is a need now. We've seen more capable people working for undergrad dropouts.
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