Differentiating between raster (pixel) and vector-based images

There are two different types of formats that exist in Affinity Photo – raster and vector elements – and it is important to understand both. Objects such as a digital photo are raster-based (composed of pixels), and objects that are drawn with the Pen tool are vector-based (formed from mathematical functions).

Raster style (commonly called pixel-based art) is based on the pixel, which is the building block of all digital art. A pixel can be thought of as the unit from which all art is produced:

Figure 1.1 – The pixel as the building block of digital art

Pixel images typically have two forms of information: size and color. When pixels are placed into position next to one another, they begin to form pictures, and subtle variation in the colors forms the detail. This is how your monitors, television sets, and other electronic devices work. The images you see on a monitor are simply created by pixels displaying their information in a way that allows us to see shapes, shades, and text. In Figure 1.2, the smooth red sphere is actually just a collection of pixels, and when we magnify it, we can see the different pixels that form the picture:

Figure 1.2 – The effect of magnification on pixelation

On the other side of digital art, there is vector-based art, and as the name implies, vector-based art is based on mathematical vectors. It is still drawn in pixels, but the mathematical equation done by the program is the primary driver of what is displayed on the screen (see Figure 1.3):

Figure 1.3 – Vector art composed of nodes