Vector or Raster….what, why, and who cares?Posted: June 11, 2011
I mentioned in my last blog that Inkscape is a vector graphics program. If you’re like me, you might get a bit confused when you hear the terms vector and raster (also referred to as bitmap). I will explain it on a basic level here, but if you’d like more information on the subject, you’ll come up with quite a few explanations if you do a web search.
Vector graphics use lines (vectors) to create shapes. The shapes are based on mathematical equations and can be stretched or reduced to any size without loss of quality. A circle that has a 1 inch diameter will still look fine if increased to 36 inches. This is important when creating an illustration that needs to be flexible enough to be used in different ways. For example, if I was creating a logo that was to be used for business cards, on shirts, and on a website, I would need to be able to change the size without losing quality.
Raster images (bitmaps) are created very differently. Instead of lines, these images are composed of square pixels (or little “bits”). This allows for greater fluidity when it comes to subtle color shading. However, image quality is greatly impaired if the image is enlarged.
To further illustrate the difference between vector and raster, see the insert below. The images on the left represent vector images and the ones on the right represent raster images. (Not to confuse the issue….. but please note that I said the left side images represent vector images because the entire insert was uploaded to my blog as a raster image by necessity.) All of the images were enlarged before they were uploaded to this post and you’ll notice significant pixelation in the top two raster images. The “vector images” are much sharper. Because pixels are square, there is not much loss of quality in the raster rectangle.
So that’s just a bit about raster and vector graphics!
Happy drawing, and may God bless you and those you love.