Digital Graphics File Formats

Nick Aldous

Raster Graphics

• Give a definition of Raster GraphicA Raster Graphic is an image format that is made up of Bitmaps. Bitmaps are pixels (individual blocks of colour) that when put together can make up an image.

Vector Graphics

• Give a definition of Vector GraphicsA vector Graphic is an image that is made up of vectors. These vectors can be paths and strokes that include start and end points that can be curved or straight.

Raster Graphics

JPEGStands For Joint Photographic experts group

Used For/Example Photographs, websites, advertisements, posters.

Advantage Very small file size and extremely compatible with almost everything

Disadvantage If you edit a JPEG multiple times it will lose its quality due to the compression.

TIFFStands For Tagged Images File Format

Used For/Example Desktop Publishing which is popular with graphic designers

Advantage Documents saved as TIFFs can save multipage documents (e.g. powerpoints) to a single TIFF file.

Disadvantage Many devices will not be able to load a TIFF file

GIFStands For Graphic Interchange Format

Used For/Example It is used for short digital animations that use lots of pictures to create the illusion of a short video. Very similar to a flipbook.

Advantage They are very good for blogging and social media as it shows a short film that is usually displayed as an image.

Disadvantage You have to keep them very simple as the more colours and changes contribute to the file size.

BMPStands For Bitmap Image File

Used For/Example BMPs can be used to store digital images, works very well with JPEG’s.

Advantage There is no loss in compression

Disadvantage BMP’s have a large file size

Vector Graphics

PSDStands For Photoshop Document

Used For/Example Photoshop Documents are used for image manipulation.

Advantage Saves layers, page formatting information etc

Disadvantage Web browsers can not read a PSD file format.

AIStands For Adobe Illustrator Art

Used For/Example Creating Logos.

Advantage They can be scaled to any desired size without loss in definition

Disadvantage They are very complicated.

FLAStands For Flash File

Used For/Example Used to create Animaton and Games

Advantage You can produce high quality files with a small file size which can include sound and video

Disadvantage FLA lets you have as many objects on one layer as you want. But SWF has a limitation of one object only. So when converting SWF into FLA objects will be placed into separate layer.

WMFStands For Windows Metafile

Used For/Example Very similar to Al files they are used for Logos.

Advantage They can be scaled to any desired size as vectors with no definition loss.

Can support both vectors and bitmaps

Disadvantage A disadvantage for WMF couldn’t be found.

File Format Capture and Optimising

CompressionDefinition Lossy compression is the way in which file

sizes are reduced by reducing the amount of information that is saved.

Advantage Lossy compression results in a closer representation of the original image.

Disadvantage Images become more pixelated as they are compressed.

Image CaptureMethod Scanner

How is it used for image capture of graphics

A scanner is used to take pictures from paper (book, newspapers) and put them onto the computer.

Method CameraHow is it used for image capture of

graphicsA camera is used to take pictures.

Method Graphics TabletHow is it used for image capture of

graphicsA graphics tablet is used to create images using strokes, colours and shapes.

OptimisingWhy would you optimise? To ensure easy easy viewing if on the

web.

How can you optimise? Images can be optimised by..

Reducing image size.

The amount of pixels within the images.Advantage to optimising

Disadvantage to optimising It reduces the resolution.