Anamacha

I'm trying to extract an object from its background. Should be a fairly simple task, but I'm finding that the steadiness of my hands isn't quite up to the task. (now, if I had a Cintiq, that might help ... anyone? anyone? [innocent] )

The background is a simple black. In order to more sharply define the edges, I put a layer over the ring, filled it with white, and set it to Soft Light mode. This brought everything out really nicely.

It also brought out a lot of noise around the ring itself, which is probably why the automatic extraction tools aren't working right.

Does anyone have any advice on how to turn all the black that's not part of the ring itself to be transparent? I've attached the overlaid file to show you what I'm talking about. And the 2d picture is the original file.


thanks

Anam

Anamacha

ok, I lied, the first file was the original file. Here's the overlaid version.


Anam

Bacardi

Try channels, choose one with high contrast, (copy it and enhance the contrast if necessary) then load as selction and there you go...

Yet I prefer a selection turned into a quickmask and soft painting...

Stroker1

Looks like you can get away with a Luminessence Select.

Hit ctrl + alt + ` to load the Lumen
Click Add Layer Mask button
Give the Layer Mask a Gauss of around 2
Image > Adjust > Levels (ctrl + l) on the Layer Mask
Play until happy
Paint the parts that Levels doesn't take care of

What Erik said. Difference is, I'm talking about using the "unseen" L channel. I don't think there is any real benefit. Anyways, it's a handy key combo.

Bacardi

I am all ears and eyes...an unseen channel...now that sounds interesting. Never heard of that before...paintings with eyes that move come to mind, and cold, humid hidden corridors that you can access by pushing that particular ornament on the wall...

Please explain...

Stroker1

First of all, my first post is an absolute mess. That's what happens when *someone* gets me up 2 hours early and I try to talk coherently.

Yeah, I call it the "unseen" channel. I believe in PS 3, nearly all HSB and HLS functionality was taken out. Cryin' shame, really. Very handy colour modes. See KPT #13.

However, for some reason, you can make a selection based on the Lumen/Light channel. I have no idea how or why this survived. Other than the key combo, there is no access to this channel, hence unseen. Stroker Tech-Slop speak as it were.

It's an extra channel to play with.
Comes in handy when the background is pure black.

Another thing to try when the background is pure black is to load all of the composite channels into one:
ctrl + click R
ctrl + shift + click G
ctrl + shift + click B

Toss that into an Alpha channel and play to your heart's content.

edit: Check this out. Instead of using ctrl + alt + ` you can select the Lumen/Light by holding ctrl + clicking RGB in the channels palette. Now that's spiffy. Tuck that away in your Bag O' Arcane Tricks.

edit2: If anybody knows that I'm wrong or miscontrueing any of the above ramblings, please correct me.
Few more things to say, but *someone* wants to eat lunch.

Bacardi

That's great...so I was right when I imagined a secret corridor and a ghost from the past. Hahaaa...gonna try this all out...

Hey Stroker, know what?

You are i-n-c-r-e-d-i-b-l-e!!!! [righton]

Anamacha

grr ... okay, RL took over and I am jot NOW getting to reply to these.

Stroker, I'm on a Mac, and your trick doesn't seem to work. what would be ctrl click for you gets me a grid.

When I try to ctrl click on the RGB composite channel, it selects some of the ring -- undesirable. I want teh BLACK bits gone, not the ring.

Maybe I could convert this to Lab mode color and select that channel? I haven't done anything with Lab yet. Let's go find out.


Anam

Anamacha

ummm ... nope, didn't help. changing to Lab mode and selecting the Luminosity channel just made a selection that, as far as I can tell, was the same thing as ctrol clicking the RGB channel.

Ugh.

Back to square one.




Anam

Anamacha

Well, I tried Magic Eraser, and that makes the edges look way too stark.

Sooo ... Erik: you mentioned something about using quickmask to select only the ring. From what I remember, using a quickmask is sort of like a way to paint your selection -- IOW, go into QM mode, paint about, then leave, and then everything that you painted would be selected.

Is that what you're thinking of? (do you even REMEMBER? )