Vector Based Graphics

One of the main issues that concern Web Designers is the need to keep the file size of an image small which in turn relates to bandwidth. Most images on the Web are bitmaps, such as jpegs and gifs, this means that information about the image must be stored pixel by pixel.

Flash uses another image representation, instead of bitmaps, it uses vector graphics. Vector graphics use mathematical functions to create the shapes. However, Flash supports two types of image formats, vector and raster. Vector graphics are created with lines and curves and descriptions of their properties. Commands within the vector graphic tell your computer how to display the lines and shapes, what colors to use, how wide to make the lines, and so on. You might have already used a vector drawing program such as Macromedia FreeHand or Adobe Illustrator to create such images.

Raster images, also called bitmaps, are created with pixels. When you create a raster image, you “map” out the placement and color of each pixel, and the resulting bitmap is what you see on the screen. The term “bitmap” is commonly used to refer to raster graphics. It is also the name of a type of bitmap image, the Windows Bitmap (BMP) format. Bitmap, or raster, images are typically created with programs such as Macromedia Fireworks or Adobe Photoshop.

The native image type for Flash is vector, so almost anything you draw in Flash will be a vector graphic (with a few notable exceptions, such as bitmap fills). Vector graphics have important benefits such as:

• Vector graphics are very small in file size and they scale wonderfully without distorting the image.
• Vector graphics can be zoomed in without any loss of resolution - try right clicking on the image above to zoom in and see the difference between a vector graphic and a bitmap graphic regarding resolution.

However they also have limitations—very complex vector graphics can have very large file sizes, and vectors aren’t as useful for photographic quality artwork. You can draw all of your vector graphics in Flash, using the drawing tools, and you can import vector artwork from other applications. Though Flash is a vector-based authoring tool, you can also use bitmap images in Flash. Bitmap images are not created natively in Flash—you need to use an external application such as Photoshop or Fireworks to create the files and then import them into Flash. Unlike vector graphics, bitmap images are not very scalable.