*Updated July 2016 to reflect visual changes in Photoshop CC. The Background Eraser tool works pretty much the same way in all versions of Photoshop if you have an older version you can still follow along*
Introduction to the Background Eraser
One of the easiest ways to remove a background or part of a background from an image in Photoshop is to use the Background Eraser Tool. You can erase the background while keeping the edges of an object in the foreground. This tool is a little bit like having a combination of the Quick Selection tool and the Eraser tool working simultaneously. The Background Eraser tool samples the colour at the centre of the brush, and deletes pixels of the same or very similar colour as you drag the cursor around your image.
The name “Background Eraser” gives the impression that this tool only deletes backgrounds, but as Photoshop doesn’t really know what is a background and what is the object of interest in the foreground, it can be used to erase any part of an image that you decide. What this tool actually does is erase chunks of colour from wherever you choose to start from. The other nice thing about it is, it also performs colour extraction at the edges of any foreground objects, so you won’t see a horrible colour halo if you paste the foreground object into another image.
While the Background Eraser is a brilliant and easy to use tool, It is important to note one drawback of using it before we go any further. As the name suggests you are erasing or physically deleting pixels from your image. When you delete a pixel, it is gone, whereas if you mask out a pixel it is hidden. So most of the time, we don’t want to delete pixels, but there are ways around this and a simple way to avoid damaging your original image is to duplicate the Background layer first and then you work on that copy within the same file.
Now, let’s go step by step and look at how to use Photoshop’s Background Eraser.
Select & Use The Background Eraser Tool
1. Start by opening an image that you want to remove the background from. in Photoshop, I’m using this lovely photograph of a bird, taken by Kwun Yeung, which you can download and use for free from Unsplash. Get the image here.
2. Select the Background Eraser tool from the toolbar . If you can’t see it on the toolbar, hold down the Eraser tool and you’ll find it hidden beneath it.
The Background Eraser tool is a brush based tool, which means you can change the size of it and how hard and soft it is.
Once you’ve selected the tool and move your cursor over the document window, you’ll see the centre of the tool, you’ll see a small crosshair (this is sometimes referred to as the hotspot).
This small crosshair dictates which colour will be deleted. When you click the mouse button, Photoshop samples the colour under the crosshair and erases all of the matching or very similar pixels that fall within the brush tip circle.
3. You can set the size of the brush tip using the tool options at the top of the screen. Click on the Brush Preset picker (the little downward pointing arrow beside the icon of the brush tip). From here you can pick your brush tip.
- Set the size to 160. I’m using this size because the original image is very big, if your image is smaller choose a smaller brush size.
- Set the hardness to 100%. Mostly you’ll use hard edges with the Background Eraser because soft edges can leave small bits of the image behind and it doesn’t cleanly erase.
- Set the spacing to 1%. This option controls the distance between the brush marks in a stroke. A low number means there is no space between the brush marks and this works well with the Background Eraser.
Tip: Quick Way To Change Brush Size & Hardness
Another better and faster way to change the size of any brush in Photoshop is to use the following keyboard shortcuts:
- Press the left bracket key ( [ ) repeatedly to make it smaller
- Press the right bracket key ( ]) to make it larger.
- Press Shift+left bracket ( [) repeatedly to make the edges softer
- Press Shift+right bracket ( ] ) to make them harder.
4. Again, on the tool options bar, there are a few more setting we need, then we’ll start erasing!
- Set the Sampling to Continuous.
- Set the limits to Find Edges.
- Set the Tolerance to about 50%.
A low tolerance limits erasure to areas that are very similar to the sampled colour. A high tolerance erases a broader range of colours. Because the background on this image has a slight bokeh or mottled colour appearance, we’re going in the middle, but you might change this as you work.
5. Bring the mouse near to the edge of the bird or whatever your own foreground object of interest is. Make sure the crosshair is not on the bird. Click and drag to start erasing. It’s ok if you bring the circle over the edges between the background and the object (that’s why it’s so cool) but it’s very important that you don’t drag the cross hairs over the edges.
6. As you click and drag you’ll see the checkerboard pattern appear in the areas you have erased. Continue erasing around the object. In some places you will need to reduce the size of the brush to ensure that you don’t accidentally erase part of the object. Don’t forget to zoom in close so that you can see what you’re doing.
7. If you find that the Background Eraser is deleting more than the colour you’re currently dragging over, you may need to reduce down the Tolerance in the options bar to about 20 or 25% and see how it behaves.
8. If you make a mistake and accidentally drag the crosshair over the edge and delete part of the object, just hit Ctrl + Z (Windows) or Cmd + Z (Mac) to undo. Then continue erasing.
9. Once you have erased an area the whole way around the object, you can either keep going with the Background Eraser tool, or you may find it quicker to switch to the normal Eraser tool and use a really big brush size.
10. Optional: Once you’ve erased the background, you can either bring the foreground that you’ve isolated onto another image, or you can paste a new background into your existing image. The background I’ve used here is a photograph by Anders Jilden, also free to download from Unsplash.