Types of File Formats

Vector

Vector graphic files store lines, shapes and colours that make up an image as a mathematical formulae. Vector graphic programmes use these mathematical formulae to construct the screen image, building the best quality image possible. The mathematical formulae determine where the dots that make up the image should be placed for the best results when displaying the image.

There are different types of vector file formats. The first is “.ai”. Adobe Illustrator Artwork (AI) is a proprietary file format developed by Adobe Systems for representing single-page vector-based drawings in either the EPS or PDF formats. The .ai file name extension is used by Adobe Illustrator.

The next type of vector file is .swf. it is a file extension for a Shockwave Flash file format, which was created by Macromedia and its is now owned by Adobe. These files can contain video and vector-based animation and sound, and they are designed for efficient downloading from the internet.

.fla is another type of vector format. It is a file extension that are used by Adobe Flash. These files store movies or animated files that have been created with the Adobe Flash application. This type of vector file is made up of points, curves and paths, and can be easily scaled.

Another type of vector format is .EPS, which stands for Encapsulated PostScript. It is a standard graphics file format for exchanging images, drawings (such as a logo or a map), or even layouts of complete pages. The purpose of an EPS file is to be included onto other pages.

The final vector file is a SVG, and this stands for Scalable Vector Graphics. It is used to define vector-based graphics for the web. SVG graphics do not lose any of its quality if they are zoomed in or resized, and every element of a SVG file can be animated.

 

Bitmap

Bitmap images are made up of pixels in a grid. Pixels are picture elements; tiny dots of individual colour that make up what you see on your screen. All these tiny dots of colour come together to form the images you see. Most computer monitors display approximately 70 to 100 pixels per inch–the actual number depends on your monitor and screen settings.

Bitmap images are resolution dependent. Resolution refers to the number of pixels in an image and is usually stated as dpi (dots per inch) or ppi (pixels per inch). Bitmap images are displayed on your computer screen at screen resolution: approximately 100 ppi.

Because bitmaps are resolution dependent, it’s difficult to increase or decrease their size without sacrificing some of  the image quality. When you reduce the size of a bitmap image, some pixels are taken away. When you increase the size of a bitmap image, the new pixels have to be created and the colour of them are based on the colours of the surrounding pixels.

 

	Bitmap graphics	Vector graphics
What are they made up of?	Pixels of different colours	Objects
What can be edited?	Individual pixels	Individual objects
What is the file size?	Large, as the computer stores details of every pixel	Small, as the computer stores details of objects, which do not require much memory
What happens when they are resized?	They lose quality	They do not lose quality
How real do they look?	Real	Not real (many of them look like cartoon images)
Native formats that the software can read	.bmp	.svg
Common file formats	.bmp, .dib, jpeg, gif, tiff, .png	.cgm, .svg, .odg, .eps, .xml