Digital Graphics File FormatsKiran Crampton

Raster Graphics

• In computer graphics and files, a raster graphics image is a data structure representing a generally rectangular grid of a set number of pixels, or points of colour, viewable on a screen. Cant be resized or quality will be lost and image becomes pixelated as they have a fixed resolution.

Vector Graphics

• Made up of vectors called paths and strokes and are made up of a start and end point that have points between them. which can then make a circle, triangle or curvy object. Can be blown up to any size and stay high quality.

Raster Graphics

JPEGStands For Joint Photographic Experts Group

Used For/Example Photographs and web format pictures. Most common used for Facebook and other social networks.

Advantage Can use millions of colours and is the base file for most digital cameras and can be used on a wide range of products. Its also a universal file and can be open pretty much anywhere weather it’s a phone or a computer.

Disadvantage Loses quality after lots of edits due to compression each time edited and quality of file. This means less pixels are saved each time.

TIFFStands For Tagged image file format

Used For/Example Desktop publishing with things like graphic design. Most common used for desktop publishing, used in adobe InDesign.

Advantage Doesn’t lose any quality due to resizing or compression and can be used to same multiple layers. Many layer within the same file which is why they are used in InDesign, they also have lossless compression which means they can be saves multiple times.

Disadvantage Large file sizes, around 20mb for a 10 megapixel image, so larger storages devices needed for long term archival use.Cant be resized. Also require certain programmes to run the files which limits it.

GIFStands For Graphics interchange format

Used For/Example Short small animations, a series of images which are played in a loop to create the appearance of a video.

Advantage They are simple to make using an animation program and a series of images, If you have a series of images such as frames from a film you can easily make a GIF. They don’t need backgrounds so can make a website look professional. They can also have transparency and be good quality.

Disadvantage They have a maximum colour depth of 256 bit, Other image and animation files and have much larger bit depths but 265 bit is normally well suited to a webpage. Cant be resized.

BMPStands For Bitmap

Used For/Example Web files, graphics, photos. Similar to a jpeg, can be used to save any pixel based images.

Advantage No loss of quality due to compression and can be high memory files providing a lot of data. Used for high quality images.

Disadvantage They cannot be resized well. Shrinking an image can change it, so can expanding the image through pixel replication. large file size for images.

Vector Graphics

PSDStands For Photoshop document

Used For/Example Photoshop files and edits. Magazine covers and different layouts. Image manipulation, page formatting and swatches.

Advantage A format created just for Photoshop use, it contains all the image and edit data, layers, adjustments and image history. Also images can be saved without a background and with different transparency.

Disadvantage Generally only recognised by Photoshop software and certain other image manipulation software.

AIStands For Adobe illustrator

Used For/Example Images and logos created in illustrator.

Advantage Wider compatibility for a native vector format, most advanced vector format available. Size and quality is not lost when compressing the images.

Disadvantage Restrained on what you can run them on. Can only be used in Adobe illustrator and a few others. Needs specialized software.

FLAStands For flash

Used For/Example Used in animation, video and web design.

Advantage Can be used to create animations and rollover button menus for web pages. Create browser-based games. They are high quality and have a low file size. Also a flash file can include videos and sound.

Disadvantage Platform problems because the way different browsers accept different files, also they are other files that can do the same as flash with less work.

WMFStands For Windows metafile

Used For/Example Logos, clipart

Advantage Can be resized to be big or small as they contain vector and raster properties. They can also be arranged easily making them easy to create.

Disadvantage They can only be used on windows products so cannot be sent elsewhere like macs etc. Also as a lot of computer users use macs this is a disadvantage for windows.

File Format Capture and Optimising

CompressionDefinition When a file size is reduced due to the

amount of file data that is saved.

Advantage It can make image sizes smaller therefore they take up less space and leaves more room for other files.

Disadvantage The quality of the file can be reduced due to less info being saved.

Image CaptureMethod Scanner

How is it used for image capture of graphics

The physical image is placed on to the glass of the scanner and the image is then scanned onto light sensitive photons that convert light into data that is put into a computer.

Method CameraHow is it used for image capture of

graphicsA shutter opens to a certain size and exposes a light sensitive sensor that takes in the light reading of where the lens is pointing and makes it into electronic data.

Method Graphics TabletHow is it used for image capture of

graphicsA way on manually designing an image on a computer and saving it as a file.

OptimisingWhy would you optimise? Large files will take much longer to load on

web pages etc.

How can you optimise? By making the file smaller through image size of colour depth. Going to ‘image size’ in Photoshop.

Advantage to optimising Means files will load much faster when there is less to load.

Disadvantage to optimising Quality can be lost due to less data being used.

Storage

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

Compression, optimisation, colour depth.

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

affecting quality?

Take away data that doesn’t affect quality such as layers and history. Condense merge layers and flatten.

What is an advantage of scaling up images before exporting?

Images will be at the right file size to render but not have a loss in quality.

What is a disadvantage of scaling up images before exporting?

Some quality is always lost through this.

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

Naming them by what the asset is what it does or what number it is.

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

Will help you keep track and close control over your different assets to use when you need to use them or want to make or save one.

Asset ManagementWhy would you use folders when storing

your assets?Organising assets can make them a lot easier to find and use and save.

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

Different folders for different category of game asset e.g. Game 1, object, terrain.