A Basic Explanation of File Formats
Feb 10, 2017
We hear a lot of confusion about file formats. There are two types of graphics created on a computer. These are raster and vector.
Raster images, also known as pixel or paint images, are made up of a whole lot of tiny dots called pixels. The number of pixels is what determines the resolution of your file. The more pixels, the higher the resolution. Each pixel has a coordinate, and the contents of that pixel are recorded and saved in a file on your computer. The computer has no idea what the actual image is other than a collection of dots. When these files are scaled or enlarged, they often create a very jagged (pixelated) image. An easy visual that is helpful is to think of the color comic books. You can see the tiny dots if you look closely. Imagine enlarging the pictures and how jagged they would become. Common raster file formats are .jpg .bmp .psd .tif and .pcx.
Vector images are very different. Instead of creating individual pixels, vector art creates objects that contain sharp, crisp lines. Vector graphics are created with software that is designed to create these intricate images and each line includes defined positions, locations, lengths and curves. They also can be assigned a color value. The coordinates of these shapes are recorded mathematically. Images can be enlarged and reduced without any distortion. They remain smooth and perfect since the mathematical formula enlarges or reduces in ratio.
We often say that fonts need to be converted to outlines. There are thousands of fonts today and often when fonts are sent from one computer to another, a substitute font can be automatically put in its place. This is another example of how vector art creates objects. When fonts are converted to outlines, they are no longer fonts. They become objects. Converting fonts to outlines guarantees that the fonts in your logo will always be exact. Vector images can also be separated for spot color reproduction.
Hope this information is helpful. We welcome your questions or comments!