Vectors and Bitmaps

Vectors

Vectors are images realized handling lines and curves. In other words by means of a graphic software package you use lines or curves in order to build images. Vectors are helpful to build logos, buttons, icons and so on. You can increase or decrease vectors as you like, but they will have always the same characteristics. In fact they are a product of mathematical formulas. So, if you increase a vector image, your computer knows that it has to modify something using a specific formula. It has to invent nothing.

Bitmaps (or Rasters)

Bitmaps are images helpful to render photos, because they are composed by pixels, where each pixel represents a different color. GIFs and JPEGs are bitmap images. Anyway GIFS and JPEGs are not simple bitmap images, because they are compressed bitmap images. In fact bitmaps are very big images, so they are not suitable to 'travel' on the Internet. GIFs and JPEGS use different compression algorithms, but we will see more about them in a next lesson. You can't increase or decrease a bitmap image's size as you like. In fact if you increase a little bitmap image, your computer has to invent some missing pixels. In other words it has not an available mathematical formula to do this job. On the contrary, if you try to reduce a big bitmap image to a small size, your computer has to destroy some pixels and modify some others according to an average of them.