Digital Graphics File Formats

Duncan Warren-Rix

Raster Graphics

• Give a definition of Raster GraphicsRaster Graphics are made up of Bitmaps. Bitmaps are made of thousands of microscopic squares. These squares are called pixels which are found in TV screens, tablets and computer monitors. Software's such as Photoshop use 300 dpi which stands for dolts per inch, so there are 300 pixels in each inch of the photograph on the software such as Photoshop. Usually the more dots per inch the better quality the photograph will be. If you enlarge a photograph it will loose quality and become more pixelated as the little squares are stretched out as shown in the photos below. If there are more dots per inch in the photo like 600 dpi, then when the photo is enlarged it looses less quality as the little squares are not stretched as much because there is more of them.

When you buy a camera the first thing people want to know is how many Megapixels it is, as the more Mega pixels a camera has the better quality photos it takes. If a camera is 14 Megapixels it means it takes photographs with 14 000,000 pixels per image which is really good quality.

Vector Graphics

• Give a definition of Vector GraphicsVector Graphics are defined by curves, points, lines and angles. Vectors and paths are what make up vector graphics. These paths or vectors travel through control points or nodes. Each path has ether a stroke colour, shape or thickness. This means if an image is made larger or smaller there is no loss in quality, this makes them perfect for company logos, business cards or billboards.

Raster Graphics

JPEGStands For Joint Photographic Experts Group

Used For/Example Commonly used on peoples home computers as a standard format. Its used on social websites so people can easily upload photos.

Advantage Websites such as Facebook and Twitter use JPEG files, which makes it easy to upload photos to the internet. Its commonly used by businesses, people and is the standard format for photo viewing software's.

Disadvantage Photos loose quality from compression and recompression. This happens most commonly from closing and opening a JPEG file and when people edit photos.

TIFFStands For Tagged Image File Format

Used For/Example Its used for desktop publishing and is common with graphic designers.

Advantage Tiffs can hold many pages to a single tiff file. Tiff files don’t loose quality with compression. You can transfer tiff files between computers and from one application to another with out the loss of quality or having compatibility issues.

Disadvantage The file size of tiffs is very large a single tiff file can take up to 100 megabytes in storage space or even more. Only the very small tiff files can be sent through email most of them are to large.

GIFStands For Graphic Interchange Format

Used For/Example Animations commonly found on the internet, which are images played one after the other in a loop.

Advantage Giff files are quite small file sizes so they don't take up to much storage space. This also means they can be used easily online as they load quicker and keep good quality. Giff files support a transparent background which helps to maintain a professional look on websites.

Disadvantage Giff files have maximum colour palette of 256 colours so they can look poorer quality then other animations or images. Once an animation has been coded in a Giff file there is no way of going back and editing the animation.

BMPStands For Bitmap Image File

Used For/Example They are similar to a TIFF and JPEG file. BMP is a raster graphics image file format used to store bitmap digital images.

Advantage There is no loss in quality of a photo in compression or recompression. Bitmap files translate well to output files like printers.

Disadvantage BMP can be large file sizes there for taking up a lot storage space. BMP files are not good for enlarging images as there is a loss of quality when doing so. This means many companies will not use BMP files as there advertisement posters, billboards or business cards in many will be bad quality.

Vector Graphics

PSDStands For Photoshop Document

Used For/Example Saving files of Photoshop commonly used by photographers.

Advantage PSD files support a transparent background. PSD files can handle simple vector layers this makes it easier for importing and exporting data from programs like Adobe Illustrator.

Disadvantage PSDs are extremely large files as there is no loss in quality due to compression. PSD files aren't usually compatible with other programs which makes it harder to transfer these files.

AIStands For Adobe Illustrator File

Used For/Example Quit often used for creating logos. Companies may use this file type as they can use it to save and even transport there logos.

Advantage Images can be scaled big or small as vectors have no loss in definition. This means advertising companies will find this file type very useful for large scale images such as billboards or small scale images such as businesses cards.

Disadvantage This file type is not useful to people who don’t have adobe or Photoshop and therefore just creates problems for people when they have non compatible file types. It is only redeemable for curtain file types its not as a universal as other file types.

FLAStands For Flash File

Used For/Example Flash files are commonly used for animations and games, making them useful for websites.

Advantage FLA files are high quality files but have small files size so they take up less storage space and still have high quality files. These files also include video and sound there for making them more useful, especially to animators and game designers.

Disadvantage It is not commonly used on home computers which can make it hard to use this type of file. If you don’t have the right software you may not be able to watch flash file videos on the internet.

WMFStands For Windows Meta File

Used For/Example WMF files are similar to AL files as they can only be used with windows.

Advantage There is no loss in definition with this file through compression or resizing an image due to vector graphics. This file type can contain both vector and bitmap components.

Disadvantage WMF files are only able to be used for video, audio, and animation system. This makes WMF files useless for photographers.

File Format Capture and Optimising

CompressionDefinition Compression is were you reduce the file

size in order to make an efficient file form that can be stored or even transmitted. Lossy compression is the way in which file sizes are reduced by reducing the amount of info that is saved.

Advantage It reduces the file size so it takes up less storage space and can also be transported easily on a flash drive or other portable storage device.

Disadvantage Pictures become more pixelated as they are compressed because they save smaller amounts of colour square pixels.

Image CaptureMethod Scanner

How is it used for image capture of graphics

A fluorescent lamp illuminates the Image, as several mirrors, filters, lenses and charge-coupled device (CCD) array are slowly pulled over the document by a belt. Two or three mirrors reflect the image. Then a final mirror reflects the image onto the lens, this focuses the image through the CCD array's filter. After this you save your document usually as a JPEG file and then you can edit it if necessary.

Method CameraHow is it used for image capture of

graphicsA camera captures and freezes a moment in time which is then saved on to a small SD card. This can then be transferred on to any editing software.

Method Graphics TabletHow is it used for image capture of

graphicsYou can design graphics by hand on tablets or just edit them. You can use a pen especially designed for the tablet to help you draw. As your hand or pen touches the tablets screen it starts to mimic you movements producing a line, curve or shape of some sort that you have made.

OptimisingWhy would you optimise? Because images not optimized normally

have a large file size. Also once you have optimized a file it takes less time to load.

How can you optimise? By reducing the size of a file so it takes up less storage space. Many formats optimize by removing information from the image.

Advantage to optimising There is more colour and a better look to images because of the large file size.

Disadvantage to optimising It is a large file there for taking up more storage space.