Wednesday, 25 September 2013

The Difference Between Vector and Raster Images/Graphics


Understanding the differences between Vector and bitmap images/Graphics 



Bitmap

Bitmap is a collection of images using tiny dots called pixels.  Each pixel is a very small pixel that is given a colour and can be moved around to form an image. When zoomed in you can see the tiny pixels individually.  

You can use adobe Photoshop to edit bitmap graphics by erasing or changing the colour of individual pixels. The human eye is not able to see each individual pixel so we perceive a picture with smooth gradations. 

When you change a bitmap graphic, it tends to lose its quality, if enlarged too much it can look unnatural and blocky and if you reduce the size it reduces the quality of the image and loses some sharpness.   The resolution of the image improves when the cells are smaller and closer together and bitmap graphics look more realistic.

The advantage of bitmaps is it is more universal, they can be read by most bitmap based software such as jpg and png.

Vector

Vector Graphics use mathematical formulas to draw lines and curves that can be edited by using a program called Adobe illustrator.  Each individual line is made up of either a vast collection of points with lines interconnecting all of them, or a few control points that are connected using Bezier curves, this gives the best results.

Vector graphics are more flexible than bitmaps because they can be easily re-sized, e.g. if you zoom in the quality remains smoother. Using vector graphics produces realistic images and 3D perspectives become more realistic. Vector images can be more scalable, as a bitmap image shows the individual pixels and the images can be made smoother by redrawing the formula.

Most vector images tend to use less memory than bitmap images because bitmaps y have to store colour information for each individual pixel which forms the image whereas  vector images just have to store the mathematical formulas.

There used to be a home gaming system that used vector graphics called Vectrex as well as other various arcade games.






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