Chances are you’ve heard of a bitmap or vector image, especially if you’re a graphic designer.  But for a lot of people just getting into the profession, you may not completely understand when the best time to use a vector a bitmap may be, or even what the difference is.

What is the difference?

A bitmap image is perfect for storing photographs or other complicated images, but won’t scale effectively, as the image is made up of rows and columns of pixels (a single spot or square that represents one color within the image, as demonstrated below:

A vector image contains mostly shapes and flat colors or gradients (depending on the program used).  Using shapes instead of pixels makes vector graphics easier to scale, as the quality of the line work will never decrease.  So when you zoom in the image should never go fuzzy, as below:

Which is Superior?

Well neither, they both have their strengths and weaknesses.  While Vector seems to be the top choice for quality, creating a photograph or highly detailed image in vector will never look as good or work as effectively as a high resolution bitmap.  Vector images used correctly can make stunning graphics used at any size, but there are limits.

While bitmaps may get fuzzy when enlarged, if the right steps are taken to ensure the picture is of high enough resolution for its use  it can be the superior choice when dealing with detail or photos.  Impressive effects are more easily achieved with bitmap images with programs like Adobe Photoshop, while vector will make it very easy to attain that crisp, neat look in a highly flexible format.

What’s the best use of each format?

Bitmap Images

As mentioned above Bitmaps are best used for photographs or detailed images.  Bitmaps are usually the best choice for websites as screen resolutions are relatively low compared to print or other types of media.    When it comes to these other types of media (like printing) it’s a matter of choosing which format will look the best on the final product.

If printing a bitmap image the resolution should be 300 dpi (or more for sharper images) for a seamless but high quality print, but can be lower for larger format prints like signage and posters.

If using bitmaps for on screen formats like video, websites or anything being shown a computer screen, try to match the resolution of the monitor or area which the bitmap is being displayed.

The most common bitmap file types are jpeg, gif, bmp, tif and psd (Photoshop) files, but some may even carry vector layers for shapes and text.

Vector Objects

Basic shapes, simple drawings, clip art and text are always best displayed through a vector format. Even the small text you see on websites is a vector font being displayed at a low resolution (converted to pixels for display on your monitor).  Text in particular benefits the most from being vector as it will keep the letters sharp, scalable and defined.

Logo’s and emblems benefit greatly from vector formats as they need to be flexible in terms of scalability and color as they are used across various formats (it’s easier to alter a vector object than portion of a bitmap).

If you try printing text as a vector you will generally always get top results, while bitmapping text (even at the highest of resolutions) will always lead to a ‘watered down’ looking print as most printers will try to display the text using halftones.  A vector text object can be printed almost perfectly when viewed under a magnifying glass, especially when printed on an offset printer.

In terms of multimedia like video and online formats (websites, etc) vector can be handy for animations and scalable effects.  If the image is static, you may find it better for download speed to bitmap certain vector images.

Most common vector formats are eps, ai, pdf and cdr among many others (which also may contain bitmap elements within the file).

Using a bit of both…

You’ll inevitably find that you’ll get the best results by combining the two formats and using their both of their strengths to compliment the weakness of the other.  While some format lean heavily towards bitmap (websites, video, etc) others will lend themselves better to vector (printable documents, logos and signage etc) it’s easy to differentiate which choice is best.  Just weigh up the options and make the decision!