What is the difference between a raster image and a vector image?

Laser Q&ACategory: Software QuestionsWhat is the difference between a raster image and a vector image?
Laser Q&A asked 11 months ago
1 Answers
Serena Staff answered 11 months ago

A raster image is made up of small pixels; common examples of raster images are jpegs, bitmaps, photographs, scanned documents, images you copy and paste from a website, etc.

You may have noticed that some images have a rough or fuzzy pixelated edge – this is a tell-tale sign of a raster image.
Ideally you want to work with high resolution raster images which have lots of small pixels to make up a detailed smooth image rather than one with larger pixels and rough edges.

There is also a limit to how much you can enlarge a raster image because of the limited number of pixels and it is not possible to easily modify their colours.

Raster images can be used to engrave but you cannot use them to cut – in order to cut you need point to point lines for the laser to follow, commonly referred to as vector lines.

A vector image is not made up of pixels but instead is made up of (vector) lines; common vector file formats are .cdr, .ai, .dxf, .eps, .pdf. Objects/designs made up of these lines can be very easily scaled up or down without having any impact on the edge quality and you have full control over what outline and fill colours you want to apply, giving you greater flexibility in the results you can achieve with your machine.

For best results and whenever possible you should always try to use vector images for both engraving and cutting.

Note: you cannot simply take a jpg or bmp and save it as a vector format, this doesn’t work – if you want to convert a raster image to vector, you need to follow a process called vectorisation which will create vector lines to separate the colours in your logo instead of using pixels.
This process can be done automatically in programs like CorelDraw or Illustrator, or manually if you prefer.