Understanding Bezier Curve Tracing in Covecto

At the heart of every raster-to-vector converter lies the same fundamental challenge: how do you approximate the pixel boundaries of a raster image with smooth mathematical curves? The answer, for virtually all modern tracers including Covecto, is the Bezier curve. Understanding how Bezier curves work and how tracers fit them to pixel data illuminates why different tools produce different output from the same input.

What Are Bezier Curves?

A Bezier curve is a parametric curve defined by a set of control points. The most common variant in SVG is the cubic Bezier, defined by four points: a start point, an end point, and two control points that influence the curve’s shape between them. The curve doesn’t pass through the control points — instead, the control points act like magnets, pulling the curve toward themselves.

In SVG path syntax, cubic Bezier curves appear as the C command: