Many of us have downloaded and edited images in the standard JPG format, and will also be familiar with other file formats like PNG, GIF, among others. These file formats are known as raster formats. However, when you try to increase the dimensions or enlarge such images, the quality drops and the photos look considerably blurry.
To overcome this drawback of raster files, another type of file format is used by many graphic designers, known as vector format.
Images can be stored in two types of file formats namely raster or vector formats. Raster files store images in the form of pixels each having a colour and all the pixels interlock to form an image. Enlarging such images or changing their dimensions causes the pixels to stretch resulting in a distorted image.
Vector files, on the other hand, are images that are built around mathematical formulas that establish points on a grid. They usually exist as .ai, .eps, .svg or PDF. Rescaling such images does not affect the resolution at all, and the pictures remain sharp.
Graphic designers use this property to their advantage when designing posters and logos where they have to change the size of images as per requirement continually. But how do vector files manage to achieve this?
As we’ve mentioned before, vector files are built using points on a grid, and two points join to form paths — curved or straight. These paths further combine to form longer paths and even closed shapes.
Each of these paths or closed shapes have their own mathematical formula, so when they’re rescaled, the formulas maintain the sharpness and quality of each path or shape. Thus a company could save their logo as a vector file and scale it down to use for their business cards, or scale it up for use on corporate buildings.
How to open Vector files?
The most common tool used to convert or edit vector files is Adobe Illustrator — one of the many software aids from Adobe which is used by graphic designers. Other common tools used include Corel Draw, Freehand, or Xara X.
The most straightforward method is to locate the vector file and then Right Click > Open with > Choose Service.
However certain files can only be opened with Adobe Illustrator, such as vector files with the .ai extension (ai is the extension for Illustrator files). In contrast, .eps files can be opened with most services.
Alternatively, in case you wanted to view the content of the file and not edit it, you could rename [filename].ai to [filename].pdf. The files will now open up like any other PDF and can be viewed in Adobe Reader or other PDF readers.
Lastly, if you’re looking for an open-source vector graphics editor, you could check out Inkscape, which is similar to Adobe Illustrator, or Corel Draw. Even though Inkscape uses SVG natively, it can open and manipulate .ai files as well.
Also read: How to prepare photos for the Web?