What's the best way to isolate an object on white background?

[ituck]

Hi,

I've been looking online and found a few tutorials but I'm not sure what the best way is to achieve this.

My sample image is attached, I'd like the background to be pure white.

Thanks for any help.

[Damien Symonds]

Hi Ildiko, when you say "pure white" do you want the natural shadows to remain?  Or should it be entirely white, like a cut-out?

[ituck]

I'd like the shadows to remain. The next step would be to try to make the shadows semi-transparent so I could replace the background, but for now I'd love to just have the background entirely white but still keep the shadows without having them look fake. 

Edited June 27, 2016 by ituck

[Damien Symonds]

1. Add a Levels layer, and immediately put it on "Luminosity" blend mode.
2. Hold down the Option key while dragging the white slider, until the background is almost all white (doesn't matter if there's still a bit of colour around the edges).
3. Paint black on the mask over the fruit.  Be as accurate as possible, using this.
4. Add a white "Solid Color" layer, invert its mask to hide it, then paint it on over the edges where the background isn't quite white yet.

[Damien Symonds]

Oh, by the way, if you wanted, you could clip a Hue/Saturation layer to the Levels layer, and drag the Saturation slider all the way to the left, to get the shadows nice and neutral.

[ituck]

What's the best way to see the mask while drawing it? it's very faint on the luminosity layer (but I might be missing something). I just painted  bit on the white area so you can see what I mean. 

[ituck]

This is what I ended up with. Looks good to me, but please let me know if it doesn't seem quite right. Thanks

[Samantha LaRue]

1 hour ago, ituck said:

What's the best way to see the mask while drawing it? it's very faint on the luminosity layer (but I might be missing something). I just painted  bit on the white area so you can see what I mean. 

Sorry, I'm not sure I understand your question. What is very faint? 

 

Also eeek!!: 



You need to do this immediately! - http://www.damiensymonds.net/art_tscs2.html

And then follow this troubleshooter with a brand new file (raw, if you shoot raw) to make sure it never happens again: http://www.damiensymonds.net/art_tscs000.html

[ituck]

Thanks Samantha! I'm not sure how that happened, I'm usually in sRGB... I'll look at the tutorial as well to make sure it doesn't happen again. 

The "very faint" was the masking - because the luminosity layer only changes the photo slightly, I couldn't tell my mask apart from the background very well. I ended up using a partially opaque colour fill layer and that helped.

[ituck]

Damien, I'm not starting a new thread because it's the same technique I'm trying on a different photo. This one is tricky because the mushrooms are so white. Any ideas of what I could do to make it more realistic? Is it just more careful masking? 

[Damien Symonds]

We'll need to talk about the mushrooms in the Raw Class please.

[ituck]

I don't think I'm a deluxe member (but not 100% sure). Am I correct in thinking that only Deluxe members can post questions there? 

[Damien Symonds]

Yes you are.  Go ahead.