Digital Graphics File FormatsHannah Barnett

Raster Graphics

• Raster Graphics are made up of bitmaps, their graphic make up is made of pixels. The pixel records the colour information of each section of the image.

• They have fixed resolutions which makes rescaling a problem due to distortion

Vector Graphics

• Is the use of geometrical primitives such as points, lines, curves, and shapes.

• Because vector images are not made up of a specific number of dots/pixels, they can be scaled to a larger size and not lose any image quality.

Raster Graphics

JPEGStands For Joint Photographic Experts Group

Used For/Example Photographs and web formats

Advantage It is a universal format so all cameras, camcorders, editing programs and everything is compatible.

Disadvantage Lossy Compression leads to data being discarded when the file is compressed. It isn’t often very noticeable apart from during editing where banding may occur.

TIFFStands For Tagged Image File Format

Used For/Example Used to handle more than one graphic image at a time within a single file

Advantage The TIFF format is not compressed so it means that no data is lostThe image quality is high due to this lack of compression.

Disadvantage Compared to JPEG, TIFF is not fully supported on everythingThe size of the images would not allow web usage due to the large size

GIFStands For Graphics Interchange Format

Used For/Example On the web to show concepts for games or to show a series of pictures as a small video

Advantage They are typically compressed into very small sizes per frame and animate easily.

Disadvantage Gif images will only support 256 tones (8-Bit) and because of this they are not recommended for highly colourful images.

BMPStands For Bitmap

Used For/Example Commonly used as a raster graphic format for saving image files.

Advantage They are uncompressed files which allow editing of singular pixels and can give an image a very high quality as there is a large range of colours which can be used.

Disadvantage They take up a large file space due to the lack of compression and can also become pixelated when scaling

Vector Graphics

PSDStands For Photoshop Document

Used For/Example Can be used to keep editing layers once saved, or can be flattened into another picture file such as a .jpeg

Advantage Can open any photo extension up and make it a .psd during editing so conversions aren’t necessary.Most printers now also support .psd so the process is more direct.

Disadvantage Photo size can become large if the image is being worked on in many layers, with lots of effects.

AIStands For Adobe Illustrator

Used For/Example Editing and creating images

Advantage Logos and such created on AI can be infinitely enlarged due to the use of vector graphics.

Disadvantage Requires AI or other editing software to open up the file. There is a limit for people wanting to just edit things themselves as they may not have the compatible programs.

FLAStands For Flash

Used For/Example Used to create animations and games

Advantage Can include sound effects, Have high quality with relatively low file sizeUsed in creation of browser based games

Disadvantage Not supported on mobile platformsMust be exported as SWF before playing, FLA file cannot play the animationFLA files can only be opened in flash (not flash player)

WMFStands For Windows Metafile

Used For/Example To exchange graphics information between Microsoft Windows applications.Used for logos and company graphics, also used for clipart.

Advantage Can contain a mix of raster and vector graphics.

Disadvantage Some of the image will pixelate due to the bitmap images in the file if rescaled.Only available on windows platforms, so is not accessible by the many Mac users

File Format Capture and Optimising

CompressionDefinition Reduction of the storage space taken up

due to a change in format

Advantage Less storage space on hardrive or USB stick due to less information being stored.

Disadvantage Lossy compression can cause loss of quality when the file is compressed by a large amount

Image CaptureMethod Scanner

How is it used for image capture of graphics

You are able to take a physical object such as handwritten work, 3D objects or printed photographs and digitalise it.

Method CameraHow is it used for image capture of

graphicsYou can capture a physical scene or object as a photograph to then put onto a computer

Method Graphics TabletHow is it used for image capture of

graphicsYou can draw or edit on the tablet and it will transfer the drawing onto the computer for more accurate editing.

OptimisingWhy would you optimise? To ensure the web version of the image is

easily accessible

How can you optimise? You can use Photoshop to edit the image size, reduce bit depth of colours, or optimise the image

Advantage to optimising It will decrease file size and make uploading and downloading of the image faster

Disadvantage to optimising A small amount of quality will be lost due to the grouping together of some pixels so preserve pixel style.

Storage

File SizeWhat could affect a Working Scale (Photoshop) document file size?

The amount of layers in the document or the image size specified

How could you reduce the file size of a Working Scale document without

affecting quality?

Flatten the image once it has been completed or merge some of the layers which have ben completed

What is an advantage of scaling up images before exporting?

To ensure that they will not pixelate/distort when the are scaled

What is a disadvantage of scaling up images before exporting?

It will make the file size larger and it will possibly take longer to export

File Naming ConventionsWhat naming conventions could you use when creating your video game assets?

I would first put the file into a folder which has been categorized as ‘Background’ or ‘Character etc. and then I would name the file itself the specifics of what it contains. So for a Castle scene I could put it in the ‘Background’ folder and name it ‘Opening Castle Scene’

Why is it a good idea to accurately name your assets?

So you don’t have to spend a lot of time looking for a specific asset, you can just search the name.

Asset ManagementWhy would you use folders when storing

your assets?You need to ensure that you have all your work well organised as to not lose any assets you have created

What folders would you create and what would you save within them

• Environmental Assets – different backgrounds created

• Character Assets – Characters which have been created

• Object Assets – any props/objects created