Vector vs. Raster
How And When To Use Different Types of Image Files
First things first, what is the difference between vector and raster?
Raster images are constructed by a series of pixels, or individual blocks, to form an image. JPEGs, GIFs and PNGs are all raster images. Every photo you find online or in print is a raster image. Pixels have a defined proportion based on their resolution (high or low), and when the pixels are stretched to fill space they were not originally intended to fit, they distort resulting in blurry or unclear images. In order to retain pixel quality, you cannot resize raster images without compromising their resolution. As a result, it is important to remember to save raster files at the exact dimensions needed for the application.
Vector images are far more flexible. They are constructed using proportional formulas rather than pixels. EPS, AI and PDF are perfect for creating graphics that require frequent resizing. Your logo and brand graphics should have been created as a vector, and you should always have a master file on hand. The real beauty of vectors lies in their ability to be sized as small as a postage stamp, or large enough to fit on an 18-wheeler!
I recently converted this logo of the Las Colinas Equestrian Center to a vector image, the original was a JPG or raster the reproduction speaks for itself but with the added advantages of a vector images there is an elevated degree of useability.
Vector SVG Files are scalable to any size, the resolution will remain constant.
Rasterized PNG created from an Adobe Illustrator vector image. Scalable to any size, the resolution will remain constant but as you can see the quality will degrade as the image is resized.
Rasterized PNG Example
Raster JPG Example
Scalable to any size, how ever the resolution will often make the image unsuitable for your project.
This was the original image file.