/jp/ - Otaku Culture

>>205633

get Fireworks 8 faget.

>>205633

You can't rotate an image without losing a little bit of your soul.

/g/

Yes, JPEG images CAN in fact be losslessly rotated.

You need a special tool for the job though. IIRC, The JPEG Wizard has the ability to do it.

yeah it's gonna look awesome when you rotate it

turn your monitor on its side.

ALL YOU HAVE TO DO IS PRESS THE FUCKEN ROTATE BUTTON YOU DUMBSHIT

>>205633
Irfanview and it's free.

Xnview can do it to JPGs without loss.

>>205675
516 KB -> 959 KB.

Guess I'll need to download one of those programs... What a pain.

1: Open in Picture/fax viewer
2: ?????
3: kill yourself knowing you have archived epic fail

>>205633
Depending on format, yes. PNG can be losslessly rotated. JPG cannot. However, the loss in quality is mostly unnoticeable.

>>205738
jpeg CAN, you idiot. there are programs out there to do it.

Just tilt your fucking head

jpegtran -rotate 90 picture.jpg

You computer illiterate motherfucker.

>>205633
DO A BARREL ROLL!

>>205749

if it were that easy thats exactly what we all would do. pictures would have signs to say "tilt head for proper viewing"

but when you do that its just not the same.

>>205686
>>205735
Trolls or are they really that fucking dumb?

>losslessly rotated

2 kilobytes off. Deal with this. Zoomed in comparison incoming.

>>205786
Quick fix until this happens.
>>205788

You must really like that picture.

>>205800

It's got a drunk, a Touka, and a sleeping loli. What's not to like?

Yes.

>>205786
Thanks, I just did it with irfanview+jpeg transform plugin too.

I checked the Optimized box though so it's a bit smaller, but it supposedly not effect image quality?

>>205846
Doing it wrong, resulting image should have the same size.

>>205828
Weird, left edge cut off and moved to the right of the image
>>205838
left edge cut off and it's just gone.
>>205786
Juuust right. Ima just save this.

>>205856
>mac

No, you're doing it wrong.

>>205864
gb2/g/

How/when did the exif thumb of this image get busted?

Anyway, thanks guys, have a Touka pic.

And a loli.

And a drunk.

JPEGs can be losslessy transformed in some ways. For example, baseline<->progressive, and changing/optimizing huffman tables (reducing file size without loss).

As for rotations and mirroring, it depends. These operations can be done in MCU units, which are at best 8x8 and at worst 16x16. So a picture whose dimensions are multiple of 16 can always be losslessy rotated and/or mirrored.

For pictures whose dimensions aren't multiple of 16 (or even 8), it's more difficult: you can "hide" pixels on the right and bottom edges, but not on the top and left. I'd explain what this allows but probably nobody is reading this, so fuck off.

tl;dr: in the case of OP's image, it's impossible. It'd be possible if you cropped 5 pixels from the bottom (from the left after rotation)

>>205938

Also, forgot to add: losslessy rotating a file can (and usually will) change its size. Not a lot, but it will, since there's some scan-order spatial compression on CD coefficients and probably some other things I don't recall right now.

Many apps can do this. jpegtrans, IrfanView via JPEG lossless ops plugin, and even the fucking Windows Image and Fax Viewer. This last one does it automatically. If it can't due to the limitations mentioned, it'll warn you that the quality is going to be decreased. I don't remember if that warning had a "don't show again" box, so be careful.

>>205969

And with CD, I mean DC. Crap, I suck today.

Most rotators re-calculate huffman tables anyway when writing (though W'IaFV doesn't), so that will throw the size off even more.

Also, to end this pointless exposition, some DCT implementations aren't "transposable", so the rotated image will show +/-1 differences even though the data is the same. Nothing to worry about since the DTC isn't bitexact anyway and +/-1 errors between decoders are acceptable and common.

Holy fuck, I did not know /jp/ was home to a bunch of picture format experts.

Did someone say Huffman? Because I think someone just said Huffman.

>>205938
>>205969
>>205998
You decided to make it your study, I see.

>>206030

Not really. This guy did, though:

http://www.impulseadventure.com/photo/rotation-partial-mcu.html

And he explains it much better than me.

That site has a lot of stuff related to JPEG, you might want to check the other pages too if you are interested on it.

(Check the Technical Articles in http://www.impulseadventure.com/photo/ )

>>205772
itt idiots who have no fuckin clue tell other idiots how to do some worthless shit.

>>206065
Oh yeah I've been across that guy's site before, good articles indeed.

who cares if the quality decreases

enjoy your bitrot and the fact that you can't do anything about it

y hello thar