The debate between raster and vector images is one that is as old as time. Well, maybe not as old as time itself, but it is certainly one that many graphic designers have talked about quite a lot. Vector and raster images are used regularly by graphic artists and this is why many of these artists have thought to ask which of the two techniques is actually better to use. This is generally a difficult question to ask any graphic artists. Its so difficult in fact, that people tend to confuse raster and vector images, so perhaps its better to first differentiate the two image techniques.
Vector images are composed of geometric shapes which have been lined and filled with blocks of colour. Creating vector images is a lot like connecting the dots. To make vector images, on any graphic design or vector illustration program, is to insert nodes or drawing points and then lines and curves to connect the nodes together. The nodes and lines are easy to modify and their quality is generally not affected by scaling of size. Essentially, the nodes and lines serve as the skeleton and the colours create the meat and flesh of the image.
Raster images, on the other hand, is, simply stated, a collection of coloured dots which are called pixels. Each pixel carries its own colour value and fills in a grid which will eventually define the image. Increasing and decreasing the size of a raster image can increase the number of pixels in the image or the actual size of the image. However, increasing the size of a raster image will result in the pixels being spread over a larger surface area. This, in the end causes the image to lose its clarity and detail. Scanned images and images on the web are typically raster images.
The Good And The Bad
Given the general definition of both vector and raster image, each different image technique has its own list of pros and cons. Vector images may be preferable to some graphic artists because the file sizes are typically smaller than the raster images. Its also rather simple to convert vector images into raster images and the quality of vector images is not dependent on the image resolution. The problem with vector images though is that it generally not capable of supporting photographs and cross-platform exchanges can be difficult.
For raster images, the benefits of this technique are that raster files are capable of handling the subtle details of photographs. Raster images are also capable of handling a wider range of effects with much more ease. Unfortunately, even if raster can handle a large amount of effects and the most intricate of details, the image must retain a high resolution in order for it to remain a high quality image. Because it requires a high resolution, raster files are generally much larger than vector images depending on how much details it contains. Also, it is harder to convert raster images into vector images.
In the end, picking the better of the two image techniques all comes down to personal preference and, for graphic artists, what kind of work is normally performed. Vector images would be better if the image being developed is something for scale or business print work, promo posters and logos because of the clean cut work and clear shapes. Raster images would be better if an artist is working with photographs and photo manipulation or very detailed images. If an image needs texture or effect based edits, raster is the way to go. So which is better, raster or vector? You choose.