The Nineteenth Byte

Edge detection includes a variety of mathematical methods that aim at identifying points in a digital image at which the image brightness changes sharply or, more formally, has discontinuities. The points at which image brightness changes sharply are typically organized into a set of curved line segments termed edges. The same problem of finding discontinuities in 1D signals is known as step detection and the problem of finding signal discontinuities over time is known as change detection. Edge detection is a fundamental tool in image processing, machine vision and computer vision, particularly...

Downgoat

i am not doing edge detection just trying to find most common color in border of image

noɥʇʎPʎzɐɹC

Yo,

Election 2016!

Discussion about the 2016 US election. Watch yo' profanity.

Helka Homba

@Downgoat you need to find the edges for that though...

Unless you mean the actual image border

Downgoat

@HelkaHomba yeah, I mean that

Helka Homba

12:29 AM

Then just loop around to all the border pixels and average them?

It's just a grid. stackoverflow.com/questions/667045/getpixel-from-html-canvas

trichoplax

You should be fine doing that without a specialised function. Looping over the border is just O(n) rather than O(n^2)

Eᴀsᴛᴇʀʟʏ Iʀᴋ

12:46 AM

@Downgoat @muddyfish would one of you like to explain why the transcript is confusing as hell with down-fishes

Downgoat

@EᴀsᴛᴇʀʟʏIʀᴋ it will only increase from here

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@Mods is it okay to use socks for star manipulation purposes?

No

okay

... what is going on

12:53 AM

@arda how goes downpearl

arda

3 hours ago, by arda

@arda umm I'm still not used to gimp and I cancelled my creative cloud subscription sooo... can anyone help me become downpearl?

Eᴀsᴛᴇʀʟʏ Iʀᴋ

will do give me a minute or 5

ASCII-only

@arda ok brb

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@ConorO'Brien TL;DR: downgoat and muddyfish have confusing avatars, star that message about skulls on the starboard, and keep messages about elections to the room for it

Conor O'Brien

I see

ASCII-only

12:59 AM

@arda Well that was easy (image -> transform -> reflect vertically in GIMP), brb uploading

Geobits

I think the point was to red/black it and add the -1 also.

arda

@Geobits yes, hence I couldn't manage it in gimp

Geobits

(i could be wrong)

ASCII-only

That's a bit harder, will do (sorry my craptop is slow ;_;)

@arda I just keep the outline right?

arda

no, kinda like this

ASCII-only

1:04 AM

@arda Oh no, wrong black ;_;

Helka Homba

Does reaching rep cap require going over it?

arda

@HelkaHomba no

feersum

What's a good way to randomly select sample of size k from the integer range [0, n)?

Where n could be very large, or barely larger than k.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@quartata you live in CA, correct?

New Main Posts

3

Q: Solve the Halting Problem for Befinge

Let's define a simple 2D language, which we'll give the incredibly original name befinge. Befinge has 5 instructions. <>^v work how you'd expect. The other instruction is ., a no-op. The instruction pointer starts out at the top-left corner going right. If the instruction pointer gets to an edge,...

Helka Homba

1:21 AM

CMC: Guess how many electoral votes Trump will get. Winner gets own cookie.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

230

DrMcMoylex

No, higher than that.

More like 260

270

@Dennis then he wins

@HelkaHomba 216

1:35 AM

Which is completely possible

noɥʇʎPʎzɐɹC

For the record, dennis thinks trump wins. It's possible.

Dennis

I'm aware of that.

Helka Homba

ok

DrMcMoylex

Could we move this to the politics room?

ASCII-only

Nathan Merrill

1:55 AM

Maine has a proposal to allow ranked-choice voting!

3

ASCII-only

@arda better

Downgoat

Want to join the ranks of Downgoat? Use the Downgoatifier!

3

ASCII-only

@Downgoat Um using it with Pearl results in a red square

Downgoat

@ASCII-only image background must be white/transparent

ASCII-only

Same as with my fish

@Downgoat :( :( :(

Downgoat

2:03 AM

i would rather nto

but tbh its because hash function bork

ASCII-only

@Downgoat 0/10 how u bork

Downgoat

@ASCII-only ;_; i dont bork its because overflow

ASCII-only

@Downgoat i posted fixed version ;_;

Downgoat

@ASCII-only ;_; but not for unhasher

ASCII-only

@Downgoat Oh ok will fix unhasher

@Downgoat pls scale svg to decent size before downgoatify

Downgoat

2:06 AM

@ASCII-only ;_; dis not my fauly

Dmitry Kudriavtsev

i have project due in 2 days but my dad refuses to give me back the raspberry pi i need because I didn't do 5x the recommended amount of math

ASCII-only

@Downgoat plsssssss ;_;

1000000000

2:25 AM

ASCII-only

@1000000000 Yeah it only works with white/transparent backgrounds

1000000000

@ASCII-only I know, but nonetheless I'm still kinda tempted to change my profile pic

Downgoat

@1000000000 will fix brb

@ASCII-only hash function still bork

ASCII-only

@Downgoat ;_______; how

Downgoat

idk

it return weird number

ASCII-only

2:32 AM

@Downgoat um

Downgoat

wat

;_; idk how it bork

pls halp maek better bg removal algorithm

quartata

You're asking for edge detection you know

Downgoat

Not necessarily

image processing in js seem very slow

ASCII-only

@Downgoat no it isn't, canvas is very fast

I can do edge detection but too lazy unless you really want it

Downgoat

@ASCII-only wil give 100pt bounty for working background removal

ASCII-only

2:40 AM

get entire image area to array -> canny edge detection -> somehow fill inside edges

Downgoat

Exactly

latter is hard

ASCII-only

Actually

Geobits

I don't see any good way to do edge detection on an image like 1000000000's though

Not for this kind of thing anyway

ASCII-only

@Downgoat not too hard, only flood fill outside with #232323, iterate over every pixel and fill with #f00 if color != #232323

Downgoat

That exactly what I am doing right now

but stil bork

ASCII-only

2:42 AM

pls upload to c9?

@Downgoat ???

Downgoat

@ASCII-only can u not modify source from browser?

ASCII-only

@Downgoat ;_;

Downgoat

you can on safari :P

ASCII-only

i can but too lazy not likely to do anytime soon

you should submit as code-challenge :P

Downgoat

Note: wont be able to halp on vsl until i get this done

@ASCII-only [status-pending]

ASCII-only

2:45 AM

@Downgoat yeah i don't mind because i'm working on charcoal atm

Charcol?

@Downgoat yes

Not a rickroll

:( now i have massive backlog: Charcoal, VSL, brain-flak integer metagolfer, Cheddar Python interface ;_;

@DrMcMoylex *Only half rickroll

Downgoat

3:26 AM

@ASCII-only wat is charcoal

Geobits

Half burnt wood

Downgoat

@ConorO'Brien avatar-change-request

Downgoat

3:44 AM

i have too many avatar change requests rn :P

@1000000000 ^ i convered yuors

Geobits

That seems a bit inverted.

Downgoat

that is the point :P

@1000000000 this is @ΛεγίωνΜάμμαλϠΟΗʹ's :|

Geobits

I don't mean upside down. I mean doesn't the red go in the middle with a black background?

Downgoat

oh

not really

the background is more white

at least stastically

Geobits

Still, it looks odd next to the other goatified images.

Dmitry Kudriavtsev

3:50 AM

@Downgoat Can you convert mine?

ASCII-only

@Downgoat 0/10 how do you not know it is ascii art language

Downgoat

2 hours ago, by Downgoat

Want to join the ranks of Downgoat? Use the Downgoatifier!

ASCII-only

also written in snek so not very good

Also something I wrote worked the first time so :D :D :D \o/

Downgoat

this is best piece of code i have ever made

Dmitry Kudriavtsev

@Downgoat Downcow?

Downgoat

3:53 AM

downgoat but with real goat picture

Geobits

Is it just taking a luminance threshold to determine color?

Wheat Wizard

The threshold is really nice!

Downgoat

@Geobits no

it determines the background color of image and uses threshold to determine how lenient it wants to be to accepting a color as the background color

Geobits

Ah. I usually use a mean threshold, where it determines it from the mean pixel values.

Conor O'Brien

@Downgoat no.

Downgoat

3:55 AM

@TuxCopter i made beter downpenguin :3

@ConorO'Brien ;___; I can make better quality

Conor O'Brien

(1) how are you making these (2) it looks like I'm in a murder scene

Downgoat

2 hours ago, by Downgoat

Want to join the ranks of Downgoat? Use the Downgoatifier!

(you should totaly star it)

Conor O'Brien

fun fact: I was originally going to have my avatar be a winged cat thingy

and this is the downgoatified version of it

Dmitry Kudriavtsev

@mods can someone please eleven my chat profile

Downgoat

@ConorO'Brien O_o

ASCII-only

4:00 AM

@ConorO'Brien RIP Conor 199something or 200something - 2016

Conor O'Brien

oh noes

ASCII-only

Star if you want me to make everyone ~~Downgoat~~ Donwgaot

4

Dmitry Kudriavtsev

@ConorO'Brien who are the mods here?

@Dennis?

ASCII-only

@DmitryKudriavtsev Dennis, Martin, Alex (afk-ish), Doorknob, trichoplax, wizzwizz, ArtOfCode is here sometimes

Conor O'Brien

but don't ping them

Downgoat

4:03 AM

@DmitryKudriavtsev chat.stackexchange.com/rooms/info/240/the-nineteenth-byte <- see on botom left where it says "Room Owners"

Dmitry Kudriavtsev

ok, what do I do to get their attention?

ASCII-only

@wat Depends for what reason

Downgoat

@wat i like your new username :P

Conor O'Brien

@Downgoat what do you look like downgoatified?

Downgoat

@ConorO'Brien ._________________.

wat

4:04 AM

@ASCII-only depends for wat reason

Downgoat

wat

@Downgoat donwgaotifying myself rn

Downgoat

@Downgoat this is definiton of blasphemy

ASCII-only

This is not working

Downgoat

@wat very creepy/10

wat

4:06 AM

yep, that's pretty creepy

cant believe nmp hasn't picked this up

1

Q: Reverse an xxd hexdump

Given an xxd hexdump such as this one: 00000000: 1f8b 0808 4920 2258 0003 7069 6c6c 6f77 ....I "X..pillow 00000010: 2e74 7874 00d3 d707 8218 10d0 2799 c545 .txt........'..E 00000020: ba96 41a1 994c 7d60 d650 d53c 44a3 8a22 ..A..L}`.P.<D.." 00000030: cd43 34aa 28d2 3c44 a38a 22cd 4334 aa28 .C...

code-golf string hexadecimal

Downgoat

@wat probably because it's on its flight to canada rn

wat

?

@Downgoat Not funny

Downgoat

sorry, but im really fearful atm :(

wat

yeah trump is winning wtf

my dad voted for trump D:

ASCII-only

@wat Give it an hour, IIRC it only posts once per hour

wat

4:17 AM

ok

Downgoat

@wat ;____________________________________________________;

wat

He would probably benefit from trump's thing fwiw

but still ._____.

Downgoat

@wat as seth meyers put it...

mınxomaτ

Yay, first 1k star project :-)

ASCII-only

@mınxomaτ ;_; how do you get so many stars

mınxomaτ

4:28 AM

Make a neat project.

wat

(._.)

feersum

Or you could get a lot of hydrogen.

wat

(.-.)

Downgoat

@feersum needs bigger exclamation on "a lot"

ASCII-only

;_; how do you get ideas for a neat project

Downgoat

4:29 AM

I am going to sleep now, when i wake up, I'm expecting the sky to be on fire ;_;

ASCII-only

@feersum pfft what are you talking about we only need 1e29kg of gas

@Downgoat s/the sky to be on fire/WWIII plus a nuclear winter to have started/

ok not that quickly but i wouldn't be surprised

Downgoat

4:45 AM

@ASCII-only that would be on inauguration

ASCII-only

@Downgoat oh true (also i thought you were going to sleep)

Downgoat

Its hard to go to sleep when you know the next hour will detemine if america will even exist in 3 months

ASCII-only

@Downgoat RIP America, in three months it will have become Panem

Downgoat

@ASCII-only s/Panem/District 13/

ASCII-only

@Downgoat What will the rest of Panem be then

Downgoat

4:52 AM

IIRC only 12/13 were bombed

ASCII-only

@Downgoat No 13 is an independent state undeground with tons of nuclear weaponry (literally) and equally as bad if not worse than Panem itself

Downgoat

5:08 AM

Yea but ir used ro be part of panem?

wat

test

@Downgoat wyh cnat yuo speel

Downgoat

@wat weve been over this

ASCII-only

@Downgoat Yes

Qwerp-Derp

wat

@Qwerp-Derp wat

Destructible Watermelon

5:11 AM

Hi @Qwerp-Derp!

wat

@Downgoat

Qwerp-Derp

Haha I don't live in America

wat

ASCII-only

I need help with language design :(

Destructible Watermelon

@Qwerp-Derp Want to work on the maze koth?

Qwerp-Derp

5:16 AM

I'm thinking of making a game in Python using Pygame

@DestructibleWatermelon Sure

@ASCII-only D'you think my BF-regex challenge is possible using regular regex (not PCRE)?

Destructible Watermelon

I hope that pair programming might work this time

ASCII-only

@Qwerp-Derp Link

Qwerp-Derp

Waitaminnit

0

A: Sandbox for Proposed Challenges

Match the BF output code-golf regexbrainfuck Your task is, when given a BF program as input and 256 1's on the line after the BF program, match the amount of 1's equal to the value of the pointer when the program halts. For a BF tutorial, see here. Example programs: +++ (255 1's) (The above ...

Destructible Watermelon

pair programming isn't on and it's already borked

WTF CODEANYWHERE!!!

I CAN'T CODE HERE WITH YOUR SITE?

wat

y

use a vps

Destructible Watermelon

5:19 AM

??

Qwerp-Derp

@ASCII-only Here

ASCII-only

@Qwerp-Derp Why does it even need regex

Qwerp-Derp

Got the link up there

What do you mean?

Destructible Watermelon

halp @Qwerp-Derp how unbork codeanywhere?

ASCII-only

@Qwerp-Derp 1. Why would it need pcre at all, that is already a subset of normal regex i.e. regex in every language, 2. \s is whitespace (` \t\n\r`) not space

Qwerp-Derp

5:22 AM

Because "PCRE is essentially Perl wrappend in regex" - Peter Taylor

But it's basically Perl

So is it possible in other languages?

@ASCII-only What you mean

I don't understand what you're trying to say

ASCII-only

@Qwerp-Derp Yes

@Qwerp-Derp what don't you understand ;_;

Destructible Watermelon

> While performing actions using Codeanywhere, the requests are sent from our app to your server. Sometimes the number of requests cause your server to block the requests and add Codeanywhere to a blacklist

Qwerp-Derp

@ASCII-only Other regex flavours*

Destructible Watermelon

shiiiiiiiiii

is borked ;_;

ASCII-only

yes you have a really basic subset of regex so it's fine in every language but idk why it even matters since you banned builtin regex anyway

Destructible Watermelon

5:28 AM

Stupid ajax googleapis

Qwerp-Derp

What how did I ban builtin regex

I don't understand you

Also what do you mean by \s

I think you may be reading the wrong question

0

A: Sandbox for Proposed Challenges

Match the BF output code-golf regexbrainfuck Your task is, when given a BF program as input and 256 1's on the line after the BF program, match the amount of 1's equal to the value of the pointer when the program halts. For a BF tutorial, see here. Example programs: +++ (255 1's) (The above ...

Cause I accidentally posted the wrong question

Destructible Watermelon

@Qwerp-Derp so how are we going to work on the maze Koth?

ASCII-only

@Qwerp-Derp ok never mind yes you posted the wrong one

Qwerp-Derp

So is it possible to do the task?

@ASCII-only?

ASCII-only

so basically you want a BF interpreter in regex?

Qwerp-Derp

5:31 AM

Yup

A very basic one

500 cells with wrapping

And guaranteed halting

Destructible Watermelon

@Qwerp-Derp pls

Qwerp-Derp

@DestructibleWatermelon What is the artifact_index code

Destructible Watermelon

I think it was about the artifact location

also I can't use codeanywhere

DrMcMoylex

test, do not respond

Destructible Watermelon

it unborked now

wat

5:38 AM

@DrMcMoylex i like pie

ASCII-only

@Qwerp-Derp good luck, in PCRE-level or better any interpreter at all is already 1. super slow and 2. so long it either has to have inline code support or be generated

Qwerp-Derp

@ASCII-only Should I reduce it down to 100?

DrMcMoylex

@wat Dang it!

Qwerp-Derp

Also you haven't really answered my question of "is it possible"

You've just said "it's really long and slow in PCRE"

ASCII-only

anagol person has one here

Destructible Watermelon

5:40 AM

@Qwerp-Derp open skype please?

ASCII-only

@DrMcMoylex wtf is this

Qwerp-Derp

@ASCII-only?

DrMcMoylex

@ASCII-only 2 people disobeyed my order to not respond... ;_;

ASCII-only

@Qwerp-Derp ok it may be possible but I'd say it's something like Tetris in GoL difficulty maybe?

Qwerp-Derp

Even with 100 cells?

ASCII-only

5:43 AM

With any number of cells I'd think

Destructible Watermelon

1 would be easy :P

ASCII-only

@DestructibleWatermelon Do you really think so?

Qwerp-Derp

Of course, all you have to do is parse the + and the -

The >< don't matter

ASCII-only

You still have to write an entire interpreter in regex, IMO the interpreter itself is the hardest part

Qwerp-Derp

and [] is impossible without being infinite

ASCII-only

5:44 AM

Hmm, maybe

Qwerp-Derp

That's for 1 cell however

Whoa wait what is that

wat

source: github.com/shinh/hack/blob/master/bf_rb_reg/bf.rb

ASCII-only

@wat pfft what is that only like 20 string interpolations as well as the entire regex :P

wat

i think there's a large amount of support code needed

ASCII-only

@Qwerp-Derp No [] will always result in 0

DrMcMoylex

5:45 AM

@ASCII-only If you're really curious, I wanted to save that link to an answer I'm working on

wat

@ASCII-only shit

Qwerp-Derp

@ASCII-only True

But it's essentially trivial with 1 cell

Compared to 100 cells

ASCII-only

@Qwerp-Derp Yes

wat

@ASCII-only i can ruby, i just cant read today

ASCII-only

@wat Oh TIL I have no idea who here knows what languages

wat

5:47 AM

yeah, I used to be Dmitry Kudriavtsev

betseg

:O

ASCII-only

@wat I know, I was here when you changed your name, I just have no idea what languages you know

wat

sorry

ASCII-only

@Qwerp-Derp Okay, let's expand to 2 cells - what do we need to do now

Qwerp-Derp

Uhhh

>< needs to be parsed

[] also needs to be parsed

brb

ASCII-only

5:49 AM

On second thought it doesn't seem to be impossible but it's still terribly long for 100 cells

wat

@ASCII-only I mostly use Ruby and C++

ASCII-only

@DrMcMoylex did you just steal charcoal numbers and non-delimited strings

Destructible Watermelon

Any good online development environments that has live pair programming like codeanywhere or cloud9 that actually works and doesn't require a credit card?

DrMcMoylex

@ASCII-only V doesn't really have string literals, rather a "string mode"

ASCII-only

@DestructibleWatermelon c9 used to work, use Floobits - it isn't online though, it's in-editor

DrMcMoylex

5:53 AM

And what numbers do you mean?

Destructible Watermelon

@ASCII-only if it isn't online it won't work

ASCII-only

@DrMcMoylex Superscript ones

@DestructibleWatermelon ?