1. A method, comprising: executing an image editor on a processor of a computer to perform: receiving a brush stroke input made by a brush tool comprising a plurality of bristles sweeping across a canvas; determining a path for each bristle along which said each bristle sweeps across the canvas; generating a bristle vector representation of each path for said each bristle, the bristle vector representation of a bristle generated from a transformation of unit bristle stamp instances that each represent a shape made by the tip of the bristle on the canvas; determining at least one of a fill color and pattern to fill-in an outline of the unit bristle stamp instances along the path for said each bristle; storing the at least one fill color and pattern in the bristle vector representation for said each bristle; and generating a vector representation of effects of the brush stroke based on the bristle vector representations for each of the plurality of the bristles of the brush tool.