If you like to use the vector format when designing most of your things, you definitely want to read this. This article is all about raster design, something that you might enjoy if you are doing vector graphics most of the time. If you want to learn more about vector graphics though, go to Firgs’s side of things where she talks Vector today.

As said, I am going to be talking raster graphics and that might just invoke the first question. What is raster? First let me borrow the technical Wikipedia definition of a raster graphic. ”In computer graphics, a raster graphics image or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium.” That might not make it a lot clearer however so let’s get down and dirty. A raster image, or a bitmap as I’m going to say, is basically the way most images that we see are built up with the most obvious being photos from your camera. Each photo is made up by millions of small dots, called pixels (remember the word megapixels?). Each of these pixels have their own colour and when we view them together (at a much smaller size) we don’t see the individual small dots, but a shape as all of these colours come together.

Bitmap graphics are most used on the computer platform. Websites in particular use graphics built up this way and as we’ve already said, so does photographs. Most art that we go about displaying on the computer screen is rasterized (meaning, converted into the raster format) even if created as a vector. This is because the files are smaller and more widely supported.

The main disadvantage when using bitmaps is that they don’t scale very well. Unlike vectors, built upon mathematical equations (read more in Firgs’s article), scale very neatly to any size whereas bitmap images do not scale well even slightly. Why so you might ask? It is rather simple! As a graphic is built up by millions of pixels, each storing a colour of its own, what would logically happen, should we decide to add more pixels in? If you may not select the answer that these new pixels won’t fill with anything, or be filled with white, you are only left with one logical answer. They assume the colour of other pixels nearby and it is this that causes so many problems mainly as they will take a new shade than the “original” pixel which will render this originally rather sharp shapes very blurry when you try to enlarge them.

So you might wonder, when shall I use these bitmaps instead of these vectors that sounds so nice? I say it is made into a much bigger deal than it needs to be. As bitmaps scale rather poorly, you would want to avoid them for things that you want to be able to be used at multiple sizes, pretty much whenever. What they do brilliantly in is web graphics like banners, headers and backgrounds. All of these graphical effects that do not need to be brought into an editor and be resized. All of the graphic that will be happy at the size where you once created them. Furthermore, all of the graphics that are extremely detailed and need to use a large colour pallet benefits largely from bitmap images as you will have a wider range to use there as you are indeed colourizing these small dots called pixels and not creating mathematical objects. All of these objects need not be created in a vector format, they work extremely well in bitmap, as they have always been created. However, if you are planning to view the graphic very zoomed in or planning to have the need to resize it in a graphics application later on. Vector would be your way to roll!