Digital Graphics File FormatsDemi Broadhead

Raster Graphics

• Raster graphics are graphics that are made up of bitmaps, they are digital images created or capture. The raster file is sometimes referred to as a bitmap because it contains information that Is mapped out to the display grid. Computer image which unlike vector graphics is made up of small tiles (pixels or dots).

Vector Graphics• Vector graphics are made up of vectors and paths. Vector

graphics are created in graphics packages and consist of shapes called objects.

• It is possible to edit each object separately, for example, change the shape, color, size and position.

• Even if an object in a vector graphic is quite large, it doesn't need a lot of computer memory. Therefore the file size of a vector graphic is often very small.

• Vector graphics are scalable - i.e. when you resize them, they do not lose quality.

Raster Graphics

JPEGStands For Joint photographic Experts Group

Used For/Example Photographs and web format; Compression technique for colour images.

Advantage Jpeg can reduce file sizes to about 5% of their normal size. This is also a universal file which means it can be opened everywhere. Jpeg’s are great for photographs, as they can do full-colour information; they have a larger compression ratios so they have a shorter file transfer time.

Disadvantage However, once you have converted an image into a JPEG file it can result in loss of quality due to the compression. Any sharp edges tend to come out blurry when you transfer them; they also have a longer page load time than the GIF format.

TIFFStands For Tagged Image File Format

Used For/Example Desktop Publishing, this format is typically popular with graphic designers.

Advantage You can save multi-page documents to a single one TIFF file. You also have the option of lossless compression therefore, you don’t lose any quality due to the compression. This file format can also be recognised by most computers; compatible with both MAC and PC’s.

Disadvantage TIFF have rather large file sizes which can take up a lot of memory; about 20mb for a 10 megapixel image. A tiff is also a specialist file which means it requires certain programmes to open the document. Most websites and online image galleries do not support TIFF uploading.

GIFStands For Graphics Interchange Format

Used For/Example This is a bitmap image format that allows you to have moving images.

Advantage An advantage of GIF’s is that it uses lossless compression; therefore, there is no degrade to the quality of the image. GIF’s also support transparent backgrounds and can show a more professional look to a website.

Disadvantage However, a disadvantage of using a GIF file format is that they store the image date using indexed colour. Once the animation has been coded into the GIF there is no way to go back and edit the image.

BMPStands For Bitmap Image File

Used For/Example is a raster graphics image file format used to store bitmap digital images.

Advantage An advantage of BMP files is that it has no loss in compression. These files may translate well to dot-format output devices such as CRT’s and printers. They files may be easily created from existing pixel data stored in an array in memory.

Disadvantage Disadvantage to using a BMP is that it has a large file size, so it take up more space than some of the other file formats. They typically don’t scale very well; shrinking an image can throw away pixels and change the image in a unacceptable manner.

Vector Graphics

PSDStands For Photoshop Document

Used For/Example This is used for image manipulation, they are commonly seen when used for the front cover images for magazines.

Advantage An advantage of using vector graphics is that it saves layer, page formatting, information and swatches. It also opens in Adobe Photoshop CS so it uses good software to create the file.

Disadvantage These files only open in Adobe Photoshop, therefore if you don’t have this software you can’t edit or create them. It is also not suitable for a blog or website and you can’t always print these images.

AIStands For Adobe Illustrator Art

Used For/Example This can be used to create logos, the graphics are used to represent a company.

Advantage These can be scaled smaller and larger; with no loss in definition therefore the images could be of really high quality; it is a vector graphic. These images will be suitable to be used on a business card of website as they are high quality.

Disadvantage A disadvantage of using a Al file is that it requires specialist software to open which limits where It can be viewed. Otherwise, you have to convert the image into another image file for it to be viewed without the software.

FLAStands For Flash File

Used For/Example Flash files are used to create games and animations.

Advantage These files are of high quality but they only have a small file size which makes them good to use on the wed as they wont take long to load. They don’t take up a lot of memory and can be stored on things like USB’s; as well as animations they can also include video and sound.

Disadvantage There is a limited amount of software which can open a FLA file as it is a specialist file. Although they have a small file size they aren’t compatible on the internet therefore they can’t run on the internet.

WMFStands For Windows Metafile

Used For/Example These files are similar to AL files, these are used for logos and company graphics. They are a windows format used mainly for clipart.

Advantage An advantage of using WMF is that they can be scaled smaller and larger with no loss of definition and this file can contain both bitmap and vector components. Files can be saved in to a JPEG form and placed straight into a Microsoft word document.

Disadvantage A disadvantage of using a WMF is that it is only available on windows platforms so they can only be generated on these. PowerPoint sometimes does not support this file format and tends to glitch, this is very likely with some types of graphs.

File Format Capture and Optimising

CompressionDefinition Lossy compression is a reduction in the file

size which is caused by reducing the amount of information which is saved.

Advantage The main advantage to compression is that it can reduce the file size and the amount of memory in which the file requires. This means your computer may work faster and your file transfers will be quicker.

Disadvantage When this file is compressed, images lose quality and appear more pixelated because less pixels are saved each time. If you send a compressed file; via email the recipient may not be able to open it as its compressed.

Image CaptureMethod Scanner

How is it used for image capture of graphics

A scanner is used to digitalise physical images; a drawing to a Photoshop document. A scanner analyses an image and processes it in some way.

Method CameraHow is it used for image capture of

graphicsLight enters the lens of the camera and is recorded by a sensor; sensor records information for all the pixels which then produces a digital image.

Method Graphics TabletHow is it used for image capture of

graphicsSome tablets have technology which allows you to control a mouse like a pen for illustration and other purposes.

OptimisingWhy would you optimise? Images are uploaded to the internet are

optimised for easy viewing on the web.

How can you optimise? You can optimise images for the web by changing the image size in Photoshop. You can also reduce the bit depth, resolution and compress the images.

Advantage to optimising By optimising an image, you reduce the file size which means that the image will then be able to download faster.

Disadvantage to optimising Optimising an image reduces the amount of pixel information, usually until images are no more than 500 pixels wide.

Storage

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

The image size can affect the document file size; in addition, the amount of colours and the layers/effects added to the image can affect the file size.

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

affecting quality?

You could work on a smaller scale canvas size to reduce the file size; also you could merge any appropriate layers together.

What is an advantage of scaling up images before exporting?

An advantage of scaling up images is that it will improve the quality of the overall image.

What is a disadvantage of scaling up images before exporting?

However, a disadvantage of scaling up images is that it can increase the file size which will take up more storage.

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

When naming my assets I will add a number on to the end of the image so I know which asset it is. For example: “asset 1”, “asset 2. If it is a character then I will name them “asset character” and if it’s a background/architecture I will name it “asset architecture”.

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

It is a good idea to accurately name my assets to make them easier to locate. Also it means that none of the work will be lost.

Asset ManagementWhy would you use folders when storing

your assets?You would use folders when you are storing your assets to make sure that when you are trying to access certain files. It will help be able to put them in a particular order depending on what it is.

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

I would create a folder which is named research in which I will place all of the researching documents which I create. Then I will have a folder named ‘pixel art’ which I will save all of my creations for my game.