Here's a neat little trick I figured out with interlaced PNGs!

Here's a neat little trick I figured out with interlaced PNGs!

Other urls found in this thread:

github.com/tylertreat/comcast
libpng.org/pub/png/pngpic2.html
0x0.st/ATK.png
twitter.com/NSFWRedditImage

CP DO NOT OPEN

MODS

That's nice. How does it work?

Bump

anyone know how to open this

lol, I actually recognize that from a certain darknet site. Nice job, OP

Interlaced PNGs will load pixels in a particular order, and the image will expand the pixels that are loaded to fill the image dimensions.

This is done in a series of passes, with the number of pixels loaded doubling with each pass.
The first pass loads the pixel in the top left corner, which I've coloured red.
After the first pass, the image renders as red.

The second pass loads the pixel in the top-middle, which I've coloured orange.

So then the image renders as red and orange.

The third pass loads two pixels half the image height below those two, which I've coloured yellow, so the top half is red and orange while the bottom half is all yellow.

The fourth pass loads four pixels which I've coloured green.

Then it goes light blue, blue, dark blue, purple, pink, and then once more through the whole rainbow.

With each pass, there's twice as many pixels added and so it takes longer to load, so until the last several passes the image is loading too fast to see the colour flashes, unless you're on dialup or something.

?

so what's the trick? what am i looking at?

MODS MODS MODS!!!!!

you know how sometimes images start off blurry then get more clear as they load in if your internet is shit? this makes it so that it's different colors instead of a blurry image.

Interlaced PNGs double the number of pixels they've loaded with each iteration of their loading, and the image is drawn in such a way that all the new pixels that load in an iteration are all the same colour; thus half the pixels loaded at any one time are a the same colour.
So, with each iteraction, the colour of an image changes, because half its pixels are a new colour.

Phones might not properly support interlaced PNGs.

webm of it on a PC?

Can't, only works the first time you load the image.

>doesn't know how to clear cache
fag

he is prolly on windows, they save every click you make


...


for your interests off course

I can clear the cache, but I don't want to.
Having a cache makes web browsing much faster.

Do it in incognito or whatever your browser equivalent is.

Try force reloading. Ctrl+shift+r.

Is this a meme?
I'm on FF and it does nothing.

>be me
>install ubuntu 16.04
>try to see this image
>ubuntu 16.04 doesn't support png images out of the box

Now I know why it's free.

nice

see read the thread before asking

>>ubuntu 16.04 doesn't support png images out of the box
wut

I did read. OP fucked up his encoding, because they all just loaded at once. It looks the same as the phoneposter.

Doesn't work.

The only option was interlacing, or no interlacing.
No way to fuck it up.
Though for some reason I could only interlace if I used PNG-8 rather than PNG-24 or 32.

are you on a fucking DSL or what?

I cant see shit, it loads sub

it doesn't support them in your computer but you can see them alright over the internet. stop bullshiting faggot

→ do it multiple times and you'll see the diff while reloading
the problem is that the file is too small, and loads too fast

not seeing it either
safari on mac
[spoiler]before you say anything, I work in iOS development, so I had to

OP, perhaps you could use this?
github.com/tylertreat/comcast
install it on openshift (free, but takes some reading), upload the pic to the server, post to HN for hipster points

You deserve it, retard.

nevermind, the program is not what I thought it was... still, guess you could use it in some VPS or something

didn't do anything for me
my computer must be too fast

Alright OP give up your secret. First time in posting in your thread.

I tried forced reloading but all it shows is a green-blue glitch. I tried downloading and using -convert but nothing works. Is there any way to recover the image?

>see red background of pixels
>people on this thread claim it's an interlaced image or cp
Not much value is going on here nor sense of this thread. OP Please kill yourself.

Those were either
1. Sup Forums shitposters
2. OP trying to bump

Either way OP fucked up and he is not responding with a proper way to recover the picture

libpng.org/pub/png/pngpic2.html
That should explain what's going on to cause it to flash colours as it renders.

There's no image to "recover".
What you see is what the image is, I've just exploited the workings of interlacing so that as the image loads it makes pixels of particular colours more obvious depending on what step of the loading it's on.

Do you both have super fast internet or something?
I mottled the colours a bit so that the filesize would be larger and thus slow down the loading, but 248kb still isn't much.

Not either one of those but I'm in Australia with shitty ADSL and it loaded almost instantly.

Sounds like a great OS (no).

Nobody deserves to use Linux.

Are you a fucking retard or just trolling?

m8, your package manager should have installed all of that, and that's if the OS didn't come with the libs already. you are clearly doing something very wrong. perhaps your system was not installed/configured correctly?

Don't feed the troll

What is it?

Doesn't work on that kind of phone it seems, but what it does is flash different colours as it loads.

Tfw a snibby crab

if you press ctrl+shift+r repeatedly (every half a second or so), you can see some colors.

In Fireworks CS4, how do I make it so that one layer erases another to create transparency rather than white?

or just CTRL + F5

All I see is some blue glitch.

Shit thread OP

this shit only works for americlaps, aka not for people with fast internet connections.

You can theoretically use Chrome's developer options to slow your internet down artificially.

That's actually kind of cool. We used to do shit like this in school.

My internet connection is a piece of shit but it's still too fast to see this effect in action...

Maybe this will help? I tried making the PNG less efficient

Thanks this helped

Good work but cant see anything, the transition was slow enough but there is nothing there

Neat.
How'd you make it less efficient?
Did you figure out how to change it to PNG-32 yet still interlace?

people in this bread no realizing there's no CP to be seen. It's literally just huge pixels that turn into smaller pixels based on how fast your internet is.

I know but but I am interested in this thread since it'd be a really good way to hide your dickpicks

wow shreklock
nice peeling away the layers of the onion that was this mystery

>hiding dick pics
Why not just use GPG/PGP to encrypt the file?
If you're being sarcastic, I'm sure there were a few people here who believed the first few posts... If you're not, then KYS.

wow shreklock
nice peeling away the layers of the sarcasm onion mystery

yeah that took about 3-4 seconds here. what the fuck is happening?

just timed it and it was 6.71 seconds haha.

16-bit per color RGBA with the worst compression method I found (filter setting 9 if you're using imagemagick's -compress option)

>48 bit colour
Can monitors even display any more than 24 bit?

Weird. This loaded instantly for me, don't see anything weird.

>tfw 1Gbps connection
>can't see shit

Most high-quality displays will go up to at least 30 bit, including consumer displays. Often they even use 36 bit LUTs internally

i would understand if it did a single pass from top to bottom like every other picture on the internet ever, but it takes like 7 passes with different colour lattice each time.

Couldn't see shit, even with

it's interlaced/progressive
jpeg can do it as well

the idea is that you get a lower quality version of the full image before the file has completely loaded

Strg + F5 forces reload of a page, including all assets

no need to clear cache

memes

aw fuck it loads instantly

...

try this

0x0.st/ATK.png

Here you go, ya faggots. My webm are always kinda shitty but whatever

...

AYY LMAO

Noice!

oh so you gotta have shit-tier connection for this to work

>open opera
>limit connection speed
>????
>profit

YEAAAAAAAAAAAH
UH HUH
YOU KNOW WHAT IT IS

wait fuck it loads too fast

>opera

>not having multiple browsers installed at once
I like the built-in VPN, though. And ad-blocking.. Pretty nice for some things I do.
I don't use it for everything but it's not a horrible browser.

It's a closed source chromium wrapper by a chinese company. It's literally the definition of horrible.

Come at me bro.
I use firefox anyway.

so is there a reason why you have chrome installed thrice or nah

If your internet is too fast you have to F12 and throttle loading.

whoa

...

Shit wrong quality settings...