Photoshop CS3 Tutorial: The Erase Background Tool
The erase background tool is powerful, but good results are only possible if you understand how it works. In this tute, we will look at all the options in the tool and use them to extract backgrounds from our images.
The tool works best if the background is all a similar colour, for example, someone against a solid colour or a bright sky.
1I have deliberately chosen a difficult image, as the girl has flyaway hair that i want to keep.
2From the toolbox, select the background eraser tool
3When the tool is selected, the control palette will display the default settings. Select the 3rd button, Sampling:Foreground Swatch This will only erase the foreground colour. Set the tolerance to 25%
Make sure Protect Foreground Colour is ticked.Selecting the option Sampling:Foreground Swatch allows you to sample the background colour most prominent in your image, so the eraser will ignore contrasting colour pixels.
Choosing to Protect Foreground Colour allows you to sample a foreground colour to protect from the eraser.
4Now we need to sample the background colour to erase. Select the background swatch in your toolbox, and double click to bring up the colour panel.
5Select the background colour with the eyedropper, right click to select a 51X51 average. This will make sure that the area sampled will be larger than just one pixel, so many shades of light blue will be included instead of just a singular blue pixel.
Next, select the foreground to protect (we will start with the girl’s hair) I will use a 11X11 average for this. Notice the colours on my background and foreground swatches.
6Choose a nice big size for the brush. Use CTRL (CMD) and the bracket keys({}) to change the brush size.
7Think of the brush as a sort of magic wand tool, that erases selections based on the colour it clicks on. The more a colour is prersent under the "radius" of the brush, the more photoshop will think it is the background colour, and erase it.
8You can now get nearer the edge, just remember that you want more of the colour to be erased, less of the protected colours, under the brush!
9Notice that to select the more fiddly edges, I am positioning the centre of the brush on top of the light blue, not the hair.
10These settings will remain true for similar areas, as soon as we get to areas with different colurs, for example the girl’s blouse, we need to select different colours to ‘protect’ - use the eyedropper to select the new foreground colour, right click to select a 51X51 pixel average.
11 You will need to change foreground and background colours often as you work through the image.
12Now open another image, perhaps an outdoor image like a beach or busy street.
Paste the selection of the girl above it, resize to fit and get rid of any stray white areas with a soft brush eraser.
13To tidy up any stray white edges around the hair, we will darken some parts of the imageSelect the Burn Tool
14From the Range dropdown options, select highlights and an exposure of 25% or thereabouts.
15Now go over the edges of the hair to darken (burn) any stray highlights or white halos on the edges.
16The finishing touches:
Image>adjustments>levels to increase tonal contrast on the background to match the girl image. This is a quick and dirty fix, As this tute is about the background eraser tool, not levels 
Position the girl so her eyes are aligned with the horizon, to make the perspective credible.
You’re done!
Popularity: 30% [?]
Bubbila wrote,
Interesting how you have kept the detail in the hair, it works well. I would normally have done this with a clipping path but I could never get a natural ballance with regards to sharpness on the edges.
I will be giving this a go.
Link | January 31st, 2008 at 10:01 pm
ivanna wrote,
hi bubbila
thanks for ur comments- I would normally use clipping paths myself, created out of channels (the great russellbrown.com has a great tute I followed on this). but sometimes, as you say, the detail can get lost. I find for some quick results this tool is the bomb. and it does give great results on hair if used properly.
Thanks for your comments- it means so much that people are actually reading these tutes!
Ivanna
Link | February 1st, 2008 at 8:17 am
Pete Thorp wrote,
Absolutely excellent. A really useful and easy to follow tutorial and has added yet another string to my growing bow of Photoshop techniques!
Thank you. I will be checking back for any more tips!
Link | February 4th, 2008 at 11:58 pm
ivanna wrote,
thanks peter- i update the site every 2 days with new tutorials- so keep checking!
it’s great to see these tutes are being read- means a lot to me!
cheers
Ivanna
Link | February 5th, 2008 at 10:17 am
Ricky Stevens wrote,
Hey Ivanna,
That’s a great wee tutorial - think I’ll use this method in the future [obviously not on pictures of myself, but maybe on little Gracie’s pics!].
As well as the tutorials, your portfolio is looking great too…
Ciao for now,
Ricky x
Link | February 5th, 2008 at 12:41 pm
ivanna wrote,
hey rico!
thanks for your kind comments- coming from you, (whose portfolio makes me weep 70% opacity tears of pure admiration) I am well chuffed…
we so need to get together for a drinkie with jamie and all the other peeps for auld times sakes!
speak soon
x
Ivanna
Link | February 5th, 2008 at 2:11 pm
Jennie wrote,
Great tut, Thanks I tried it and it is Fab. Fun too.
Jen
Link | March 29th, 2008 at 7:51 am
fre3style wrote,
thx for the great tutoria, i’ve been a long time searching and learning how to remove backgroung from hair, and finaly! thx to you… it’s great tutor and very quicky step!
Link | April 7th, 2008 at 7:54 am
Rebecca wrote,
Wow! Please give us more tutorials. I really like your style of explanation. I think yours are my favorite tutorials of all those I’ve seen (and I’ve seen a lot of them). Beautiful work, too! Thanks.
Link | April 13th, 2008 at 5:09 pm