With the Background Erase Brush Tool, you can erase pixels of a similar colour. This makes it useful for tasks such as erasing the background while leaving the foreground intact.
The following settings can be adjusted from the context toolbar:
Width—the brush (stroke) size in pixels. Type directly in the text box or drag the pop-up slider to set the value.
Opacity—how see through the brush is. 100% opacity erases pixels completely on the first pass. A lower opacity only partially erases the pixels.
Flow—how fast the brush effect is applied (1% is very slow, 100% is immediate). Type directly in the text box or drag the pop-up slider to set the value.
Hardness—how hard the edges of the brush are. The brush appears softer as the percentage decreases. Type directly in the text box or drag the pop-up slider to set the value.
Force pressure to control size—Click to control brush size with pressure if using a pressure-sensitive device. This overrides brush defaults.
More—click to display the Brushes dialog to access advanced brush settings.
Stabiliser—enables stroke stabilisation using either a Rope stabiliser or Window stabiliser mode; the former drags the stroke end by a 'rope' to smooth the stroke but lets you introduce sharp corners at increasing rope Length (radius) values by redirecting the slackened rope; the latter will smooth the stroke by averaging sampled input positions within a Window whose size is configurable.
Tolerance—how dissimilar the pixels can be compared to the sampled pixel for the pixels to be erased. A low percentage affects only pixels very similar to the sampled pixel
Sample continuously—if this option is off (default), samples the colour only once on the first click. When selected, samples colour continuously as you drag.
Contiguous—when selected (default), affects neighboring pixels as well as the sampled pixel colour. If this option is off, affects only the selected pixel colour.