Invert or negate acv curves

[domdaigle]

Hi, I was wondering if someone knows how to invert or negate a .acv curve. It is possible to do it by "eye" but I was wondering if there is a way or somekind of plug-in that will do it precisly or mathematicaly. Here is an exemple:

[Stroker]

Go into Arbitrary mode, save as an *.amp file, load *.amp into an array, output in reverse. I mean, upside-down.

AMP (http://tech-slop.serveit.org/amp/index.shtml)

Give me 1/2 day and I'll knock it out in VB iffin ya feelin for it in PC/Win. I would do it right now, but I'm out the door.

I'm sure the same can be done with *.acv if you've got the yarbles for it. I ain't got the yarbles for it, though.

Another optioon would be to do it manually using Input/Output.

[domdaigle]

Hi, thanks for your reply. I've been able to save it as an .amp, wich is somtheing I've never did before but I can see the potential. I might sound stupid but I don't know what you mean by "open it in an array". If i understand there is a program where I can load it and save it reversed. Can you teel me wich program to use?

I am on PC, so if I understand correctly in the last part of your reply you're saying you can write a program to do that automaticly. If it's the case it's really nice from you and totally appreciated. If not I guess if you tell me wich software to use to open, reverse and save the inverted file, I should be ok.

I tried the input/output technic before but the curve doesn't react the same way when the point are move to the opposite value, I guess it's a question of tension in the curve or something.

Thanks again, can't wait to see what you come up with.

Dominic

[MrJelly]

I might sound stupid but I don't know what you mean by "open it in an array".

Don't worry, that's just Spectre speaking fluent Geeka. Not so much you sounding stupid as him sounding brainy. Any minute now he's going to turn up with a plugin that does exactly what you're looking for and fixes you coffee at the same time. I'd advise you to lay in a store of cookies.

[Stroker]

Sorry I've been taking so long with such a little thing. My weekend was a little longer than usual. Plus I cut two fingers fairly deep (it's hard to type with Bam-Baids on fingers). I got some time coming tomorrow and I should be able to come back up to speed.

Yeah, get the cookies ready. No-Bakes would be good.

[MrJelly]

Sorry to hear about the fingers, Stroker. How'd you pull that little stunt?

[Stroker]

One cut is on the middle finger of my right hand. Not really a cut, but a missing chunk of skin. I didn't notice this until I saw the blood. No idea how this happened. The second cut was with a box cutter right on the index of my left hand. Deep, clean, and right on the pad. The Bam-Baids are off and both are doing fine - I just have to watch the salt and lemon juice.

Finally got to work on Mickey Mouse. You know, I really hate doing file I/O in VB. Had to do some serious brushing up.

As it turns out, I'm an idiot and not as easy as I was hoping. Not just the file I/O, but thinking about the diagonal has really thrown me for a loop. But there is something about AMP files where a shortcut may be hidden.

I'm gonna give it a break and go do some dishes.

[Stroker]

Meh. I did manage to do it with ACV files. But you are not going to like it. The way Photoshop handles corners just isn't good for this kind of thing.

Save ACV from Photoshop. Start up ACVInvert2.exe and follow your nose. Load the result into Photoshop.

No error checking, so don't get too fancy with it.

[domdaigle]

thanks a lot, I will post a reply as soon I as test the plug-in. You guys are awesome!

[domdaigle]

it's almost there, the only thing is that since acv is used there is less point on the curve so photoshop interpret the invert curve a little different than the original curve, but I think I can fix it by hand.

Thanks again, and if you figure out how to make it with amp I'll be happy to test it. I wish I could help you with the code but I have no clue how to do it.

Thanks a million again

see page 2

[domdaigle]

Ok, I figured a way to make it work perfectly. At first I was trying to invert an acv with just a few point and photoshop was no doing a good inverse interpolation. Then I added points on the curve(by hand) without modifying it, and boom it inverted it perfectly.

I guess the plug-in could work perfectly if it was adding point at all the input/output value possible on the curve, and then reverse it. That way it will not really have any interpolation to do since the points are so close together. I'm not sure it is possible cause the curve interpolation is probably done in photoshop itself. but as I said I'm no mathematical genius.

Thanks again, and if all I have to do is add a couple points by hand it's no big deal.

Amazing work, thank you!

[Parker]

Side note: No intentions of hijacking here...

Just an observation, esp since i'm new to posting. Stroker your posts are great... Not sure how long you've been involved with PS software but coming from a guy who's used it since '97... I've learned a thing or two from you. Thanks.

Rob