Raster graphics or vector graphics: which one to choose?

If you’re working in a software design program a lot, you’ll probably find yourself switching between different types of graphics. Which do you use more? Well, if you have a digital camera that you regularly take photos with, you probably go into a program like Photoshop to modify or make changes to your digital photos. Digital images are made up of pixels, which resemble small squares, and a large number of them make up the image. Looking at an image of a certain length, it looks like a picture, but when you go into the program of your choice and use various tools, one of which is the magnifying glass – zero closely and you can see that each image is made of many, many tiny squares.

Your digital images and most photos you see on the Internet are raster images; that is, they are made up of a multitude of squares, which form a bitmap, or series of pixels. When you try to enlarge a digital image, you may notice that the image becomes blurred or blocked. Raster images need to be rescaled by a factor of 8 for the printer settings to compensate, so it’s hard to rescale much with raster art. You can change tonal values, color values, and adjust saturation settings much more easily. When you’re working on a digital image in Photoshop, you’ll see that when you delete something or change it, the pixels in the background change with it.

Now suppose you are working on a line drawing in one of your programs, such as Corel Draw or Illustrator: You are working on a vector image that is also known as outlines, paths, or curves. The lines are connected to each other by tiny points known as “nodes”. When you try to make changes to your vector drawings, you do so by manipulating the nodes. If you’re a skilled graphic artist, you’ll know that if he removes or adds new nodes to the outlined drawing, it will gradually or drastically change the shape, depending on how many nodes he manipulates. However, you have great flexibility when working with vector images. As long as you have a closed path, you can fill the shape or object with color.

Using a program like Corel Draw, you can make a raster image easier to work with by tracing vectors. This is a simple and quick procedure depending on how many nodes make up the image, leaving you with an image in vector outline format. When I do this, I use a tool called “Quick Tracking”. Results may vary if I’m using Contour Trace, Quick Trace, or Centerline Trace. Vector images scale well and are also used in flash animations.

Additionally, the files may also vary depending on whether you are using vector or raster art. Vector art is lossless, which means that file compression will not cause a loss of image quality. A good example of lossless formats would be .GIF. On JPEG raster images, permanent data loss may occur to reduce file size. This is because the JPEG format is a lossy compression… which means that some loss of image quality can be expected when the image is compressed. This could present a problem in projects where details are important, such as spreadsheets. This type of loss is more acceptable for video and sound files, where the loss is not significant enough to be detected.

There is a lot of great information to be found on different file sizes, image quality, and ratings, so you can be sure your project will be a success with a minimum of guesswork. And if nothing else, you can always seek the advice of a professional graphic designer, if not hire one outright if you have no idea about a major project and are short on time. Good luck!