/tech/ - Technology★

>>848466 (OP)

With lossless you just have to uncompress and hash the data, which will be the same no matter the format. With lossy compression you can't, obviously.

When did this place become full of 4chan-tier faggots?

>>848481

That still works with lossy compression, as long as you don't touch the image itself, but only change metadata or do lossless recompression (like jpegoptim tries by default).

>>848466 (OP)

https://en.wikipedia.org/wiki/Perceptual_hashing

there is photodna for the copyright mafia, but it is proprietary and not public

>>848466 (OP)

imagemagick and/or ffmpeg could do that.

search the web.

>>848481

Nice meaningless post.

>>848466 (OP)

>I'm wondering if there's a hash for images that is made from the pixel data instead of the binary data.

>Does this exist? Is such a thing even possible?

No. Hash functions _only_ work on binary data. Pixels are RGB or RGBA. As you see, you can't hash pixels.

>>848533

>meaningless

Just because you can't understand doesn't make it meaningless. He correctly answered OP's questions.

I think python-scikit-image has some >>848488 function you could try.

>>848533

He answered the question fine. Are you dumb?

>>848481

/r/gatekeeping

>>849355

>asking extremely simple questions on anonymous boards and getting offended by the replies

>>848541

>No. Hash functions _only_ work on binary data. Pixels are RGB or RGBA. As you see, you can't hash pixels.

>Pixels are RGB

Pixels are typically represented in computers as 24 binary digits you to stupid fucking retard nigger.

>>848488 THIS

>>848495 Glow-in-the-dark, but still correct.

And the rest can't comprehend OP's wording...

Anyway we need an open source alternative,

and IQDB is way to old-fashioned (*booru)

Realted:

https://news.ycombinator.com/item?id=9868421

>>849355

I've never even heard of this. Why is leddit coming here?

OpenCV (pretty obvious) https://docs.opencv.org/3.3.1/d4/d93/groupimghash.html

OkCupid's test results https://tech.okcupid.com/evaluating-perceptual-image-hashes-okcupid/

Speed increases with BK-trees http://tech.jetsetter.com/2017/03/21/duplicate-image-detection/

The old classic (assuming you know aHash, wHash and dHash) https://www.phash.org/

For R-fags https://cran.r-project.org/web/packages/OpenImageR/vignettes/The_OpenImageR_package.html

For the insane ones https://pippy360.github.io/transformationInvariantImageSearch/

>>849355

The true face of /tech/

>>849500

The Dunning-Kruger effect in action, gents and gents