Raster vs. Vector

Raster and Vector are two ways a computer can store a graphic image in digital forms. Vector images are made up of lines and they consist of mathematical descriptions of the lines that made up the image. Raster images are made up of dots.

 Raster Images

There are a number of different raster file extensions such as bmp, png, gif, tiff, jpg and psd. They often get called ‘Bitmap images’, this is because they are made up of tiny squares called pixels.

The file extension which is the most popular raster graphic file format is JPG/JPEG. This file extension often gets used on web pages alongside GIF and PNG. GIFF or ‘Graphics Interchange Format’ is used to save graphics and illustrations rather than to save a photograph. PNG or ‘Portable Network Graphics’ is known as ‘third of the internet’ bitmap image formats. It is likely by creators of web pages. TIF/TIFF or ‘Tagged Image File Format’ is used for printing. The sizes are much larger and contains additional information which as paths, comments ect’ which is used by printing devices. BMP is BitMaP which again is the basic raster format however it’s rarely used. BitMaP aren’t always displayed on internet browsers and they show pixels with their colours being defined and also with a minimum compression.

Vector Images 

Vector images usually contain curves and fillings. These types are the best formats for logos which could be used on business cards and on a billboard. Getting a raster file from a vector file which means reversing it is complicated and sometimes not actually always possible! You can change a BitMaP into a vector and this is called Vectorisation or Digitalistation. They are made up of lines rather than dots like Raster Images. It consists of mathematical descriptions of the lines that make up the image.

Example of Raster and Vector   

Using Microsoft PowerPoint I have gone to the ‘Insert’ box and selected ‘Text Box’. I have then drawn my text box and selected the letter S as my example to show the difference between Vector and Raster images.  I then took a screenshot of my screen and cropped it down to just the S and placed it next to my order text box with the other S. I then placed them side by side.

                       I then zoomed into the two images at 226% and it is clear in the screen shot below that one is a vector image and one is a raster image. The vector image looked smooth and the lines/curves are visible however on the raster image the pixels are visible. That’s how to see the different of a raster image and a vector image!

 

zoomed into 226%