High Quality JPEG Recompression Artifacts - 500 saves

[vvneagleone]

From everything I've read about JPG compression, this is not at all what I expected.

First, some random 8x8 px blocks on the right lighten, then the others lighten as well? Something to do with minor changes in contrast between neighbouring pixels?

[leegao]

Oh right, also forgot the obligatory comment:

HOLY SHIT, IT'S LILY FROM HIMYM, WTF!1!!11!11!

[TheAmefist]

How does this happen and how can you prevent it? Please reply back I don't know much about photos.

[wikichris]

@TheAmefist JPEG uses lossy compression so the lossy bits which aren't noticable at first keep getting compressed again and again. You can stop it by using a lossless formats and export from them to JPEG if needed.

[blenderuser]

use a lossless format, for example PNG or TGA.

[fishbonezken]

Holy cow, why does it do that....

[kodackxgabock]

YOu sir, have no life.

But thank you for the heads-up

[MrBiskri]

e=mc²

[r32adt3db]

@MrJsquared91, yep, most of them are stuck up bitches that treat their guys like shit.

[malineeelike]

Willow ♥♥

[Bluedrake42]

she's still hot

[ToribioKid]

why is alison hanigon there ?

[patsosas]

Because she's HOT!

:D

[ToribioKid]

lol xD

Go willow

[Cypeq]

can u make another vid with 12/12 compression ? becouse it's obvious that compression artifact will amplify.

[MrGrundlefun]

Done. See the reply.

[tommyrulzzz]

american pie! :D

[coici]

500回jpg圧縮。(たぶん)200回位で劣化しなくなるとい­う性質。

[MrBiskri]

Date movie!! XD

[deifo]

You could have used ImageMagick and a custom script to make the whole experiment automated. You could have done 1 million saves without added effort just to see what happens.

Another idea: zoom into some regions (face, background, etc) and see if you can spot changes in quality.

[FreeTheRocks]

This upload is moronic. Open the same picture 500 times in Picture Viewer and NOTHING will happen to the picture because you are not re-compressing or changing the picture in any way.

[Yoonjin90]

? ur very stupid kid.

He didnt just open the program if u learn how to read. i recommend a book 4 u.

[FreeTheRocks]

@Yoonjin90 What part of "He is CHANGING the picture 500 times by SAVING it in Photoshop" didn't you understand? Smart people don't fire up Photoshop to simply "view" a picture...and smart people know NOT to press "Save" or "Save As" if they only "viewed" a picture in an editing program like Photoshop. How about the book "Simple English" for you?

[leegao]

@FTR:The "quality" of the end result is set at 5/6 the original quality. As the preserved/compressed regions are kept the same within Photoshop (the same compression algorithm is applied cumulatively), the end result is that alterations are amplified. Therefore the purpose of this video isn't to merely get people to Open and Save the same image over and over again, but rather to demonstrate what would happen if one were to do so. There's no need to get nasty.

[FreeTheRocks]

@leegao If you did not change the photo....then you do NOT use "save" or "save as".....and if you do not intend to change the photo....you don't use an editor like Photoshop....plain and simple. What is so hard to understand about this....especially the first statement?

[KzrrainzYes]

@FreeTheRocks

That's why the purpose of the video is to show what happens when you DO.

[leegao]

@FreeTheRocks There's a metaphysical abstraction of human ingenuity that we commonly call curiosity. It's the only fuel that drives your stereotypical computer programmers (the unkempt programmer, wasting away in a room full of other unkempt programmers...). Take that away, only managers are left behind with their silly schemes to generate revenue from good looking graphics... Sure, these are curious endeavors, but we're less concerned with the output than the process.

[SubGumCRyno]

If you'd save at 12 the whole time, would it have produced the same result?

[MrGrundlefun]

Take a look at my video reply.

[AJtheory]

HOW IMMA' ET YO MAMMA

[mikepavy]

This is because JPEG works by compensating data storage for hue/luminance in a picture. Colors appearing smaller on greyscale (more color absorbent) are sacrificed foremost, this is done to give a smaller file size.

Try doing this to a picture with a lot of yellow present and you'll notice it quickly deteriorates after save compression.

[AJtheory]

I always thought this chick would look better if she got her teeth fixed...

I was right...

Now all she needs is just a *tad* bit of lip plumping (mainly the upper lip, unless she likes rocking the Liz Phair thing)

(I'm not talking about going all psycho Lisa Renna or Octomom, but just a subtle tad bit)

[ravenhpltc242]

I miss Alyson Hannigan as a redhead. She was so adorable in the first season of How I Met Your Mother.

[Nickelodeon2002]

I love band camp.

[NiCLuvIn373]

@Nickelodeon2002 doesnt every1? lol

[elmeeone]

wtf

[freakencold95]

lol thats the chick who put a flute up her pussy XD

[thomas997]

wow

[JAMBigE]

Interesting that the loss of information seems to occure in spots, not the entirety, and in the same spots.

[JAMBigE]

ok, I 'm curious, what if you saved it at 12?  I think my camera makes pics at 97%, so saving at 100, resulted in bigger file, but it still had less unique colors.

[MrGrundlefun]

I posted a video reply to show this. It comes out worse.

[SexCyberGuideCom]

nice video

[coolstream1]

Still fappable!

[n3rdbear]

lmao damn dude that's hilarious opening and saving a pic 500 times. Whoever was around you must have thought you had OCD.

[LoleScania]

That's pretty bad. =/

[MrBiskri]

boring!!

[XStreetKingSX]

American Pie

[Booshibonton]

you did the entire thing by hand?

wow

[MrGrundlefun]

For the first video, sort of. I used an action to save the two files, then all I had to do was click a button in another program to give the one file a serial number. I mapped F1 in photoshop to "Run Action", so all i had to do was go F1, click, click, F1, click, click... 500 times. It didn't take long. For my second video, I wrote a script in photoshop to do it.

[magnoid]

well of course there are going to be amplified artifacts if the quality level is not 12/12

[MrGrundlefun]

12/12 makes it worse. Take a look at my video response.

[frvfilms]

this one time in band camp....

u could consider this tech art?

[papatoony]

@frvfilms LOL that's ALL I can think about every time I see this chick! It always makes me laugh.

[IXISIXI]

I like the picture you chose

[t3hAlien]

I'd save THAT picture a hundred times, if you know what I mean.

[MedeaMelana]

I sure hope you automated this! :-)

[tkwiredcom]

According to his reddit post, he didn't. He actually set up a photoshop action, bound it to F1, and the process was F1, click, click...500x.

[MrGrundlefun]

tkwiredcom is correct. But for subsequent tests, I wrote a script in photoshop.

[habeeb1t]

interesting experiment

[Potatoguy123]

Hm, I was expecting some 'scary' shit to pop up at the end... Semi-disappointing.

[kentweirdo]

Matter breaks down over time, doctor!

Start the failsafe, damn you! Start the damned failsafe!