2D Image Representation – Vectors

Definition

An image formed of a geometric path; for example, lines, fills and curves.

Geometric Primitives

Vector images are comprised of geometric primitives, which are:

• Points – locations in euclidean space (x and y coordinate)
• Lines – these connect two points, and have their own attributes, such as weight (thickness) and colour
• Curves – anything from an arc to a full circle. These will have a centre-point, radius, start and stop angle, thickness, colour, and fill
• Polygons – a collection of lines which have a shared start and end point, forming an enclosed shape.

Paths

An outline of a shape or illustration made up of a series of connected points. This is stored as a series of coordinates, meaning that it can be scaled without introducing the sort of blockiness that resizing a raster image would create.

Voxels

In a 2D space, such as in a raster image, the image is created using pixels. A vector image must be rendered to create a raster for display or printing. Prior to this occurring, the shape could be manipulated – for instance, by rotation, skewing or morphing. Prior to the rasterisation process, points in the image are described as voxels – these describe a point in 3D space.