A Definition of Vector Graphics
roboma | Monday, January 16th, 2012 | Comments Off
For a simple definition, vector graphics are those that make use of only basic geometric elements (called primatives) like lines, curves, shapes and polygons which can be explained by mathematical equation. To construct a vector graphic, these geometric primatives run through locations called control points that have a specific x,y coordinate. These paths can be assigned a color, shape, thickness and fill which are used to make highly complex and detailed images.
This mathematical construction is what makes vector graphics so powerful. To understand their benefit, we need to contrast against raster graphics. Although you may not know it, almost all the graphics you view are raster, which means they are comprised of small rectangular cells called pixels. Figure 1 below illustrates the differences between how vector graphics are created versus raster.
| Figure 1 | Figure 2 |
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The smaller and closer the cells are together, the better the quality (resolution) of the image, but the bigger the file needed to store the data. Because of this, resolution is typically only as high as it needs to be for that specific application. If you choose to enlarge or manipulate the image, you have to enlarge or manipulate the pixels themselves. The result is that the graphic will lose the smoothness of lines and curves. Because devices like monitors and printers only display raster graphics, vector graphics are converted to raster based upon the mathematical instructions contained in the vector file. This means that as a vector graphic is enlarged, it just brings in more pixels to construct the raster graphic. The result is a smooth, crisp image no matter how large as Figure 2 illustrates.
This means that a vector graphic of a company logo for example could be used on a business card or enlarged to the size of a billboard and look exactly the same. The actual file size of the vector graphic would be no different between the two applications. Again, it is just a set of mathematical instructions telling the device how to render with pixels (raster). The other major advantage of vector graphics is that the parameters of objects, such as color, shape, thickness and fill are stored and can be later modified. This means that moving, scaling, rotating, filling etc. doesn’t degrade the quality of a drawing.
We always ask customers to provide a vector graphic if possible because it provides the highest quality of text, logos, and graphics no matter what the use. Hallmark utilizes Adobe Illustrator to edit existing vector graphics or create new ones. We often convert raster graphics we receive from our clients into vector so we can use them on the wide variety of products we produce like nameplates, membrane switches, graphic overlays and marketing collateral like signs and banners. We’ll be posting another article soon with more details about how we convert raster graphics to vector.
