Jul 08, 2005

Bitmap VS Vector

Being the only graphic designer where I work, I get asked about the difference between vector and bitmap graphics all the time. Pear Logo Design has a great informative article on this (ooh, with pictures!) but most of the people that ask me about it wouldn’t take the time to read that entire guide, so I thought I’d break it down real short and simple.

Bitmap

Filetypes: This is the type of graphic you are probably most familiar with. Just about every graphic you see on the web (with the exception of Flash) is bitmap. .JPG, .GIF, .BMP, and .TIF are some of the main filetypes.

Details: Bitmap graphics are made up of little squares of color called pixels. For instance ‘ if you have a logo that is 50’50 pixels (50’50 = 2500 total pixels) and you try to enlarge it to twice that size, you still only have that total of 2500 pixels to draw from, so the quality degrades significantly and it becomes pixelly or blurry.

Advantages:

The format for photographic content

Widely supported on the web

Disadvantages:

Cannot be enlarged without significant quality loss

May have much larger filesizes

Vector

Filetypes: For the most part vector files are proprietary to the software in which it’s written (.AI for Illustrator, .CDR for CorelDraw, .FLA for Flash). The most common generic Vector format is .EPS, although .SVG is starting to get more and more popular.

Details: Vector graphics are created with shapes and math. If you had a circle in vector, the information in the vector file would something like ‘circle: 1 pixel black border, white inside, radius 50px’ and when you opened the file your software would redraw that circle based in the information. Since vector is basiced on math rather than pixels, you can resize it to any size and it won’t lose quality.

Advantages: