Digital imaging software can be divided into two types: raster-based and vector-based. For those who aren’t sure which one to use or how to solve common problems with them, here’s a brief guide to how they work and their pros and cons.
The fox image on the left is a raster-based image. Raster-based software expresses an image in a grid of dots, called pixels. Each pixel is a certain size (depending on the resolution of the image), so trying to make a low-resolution image bigger often results in the pixels being enlarged, making the image look blocky, as you can see from the inset above. Each pixel can be a different hue, tone or shade. Images that are created with raster-based software can therefore feature a wide gamut of colours with subtle shading and blending effects. Because of this, they are often large file sizes. This can make them harder to store and send via email, or it can slow down the process of image-editing or painting when you’re working with a large file. Raster-based software is often used for digital painting and image-editing and includes Corel Painter and Adobe Photoshop. They’re best for creating natural media effects, colourful hues, shading and tones, and effects.
The cat image on the right is a vector-based image. Vector-based software doesn’t count every single pixel. Instead, vector points tell it where an area or shape begins and ends, whether its lines are curved or straight, and what colour to fill it with. Because it expresses lines and colour fills rather than pixels, an image created in vector-based software can be resized with no loss of quality, as you can see from the inset above – the background pattern is still crisp and clear despite being magnified. And as vector-based software doesn’t need information about every single pixel, its file sizes are typically smaller, making them easier to work on, store and send. However, because less information is included in the file, vector-based artwork is often limited to smoother, more solid blocks of colour and tone than raster-based. Vector-based software is often used for illustration, technical drawing and typography and includes Adobe Illustrator and CorelDRAW. They’re best for creating precise line and colour, patterns, and details.