Vector and raster Graphics

Raster Graphics

Raster images or rasterised images are made up of many different coloured pixels, raster graphics

allow for a greater amount of colours compared to the vector images that are very limited on the

colour you’re allowed to use. Raster images have downsides one of these being that it cannot be

stretched or enlarged much once its created because they tend to stretch the individual pixels in the

image, therefore making its appear blurry and overall give it a very low quality that is not fit for

publication.

There are many different raster drawing packages out there, one of the most known being

Photoshop which allows the user to create or modify Photos, these can be images that look as

stunning as photos. Photoshop allows for many more colours than packages such as illustrator which

limits colour. Photoshop allows for exactly 16 million colours if you are creating a 24 bit photo file, 8

bit allows for 256 different colours and 1 bit is black and white colour selection. Photo files which

are normally created using flash (24 bit) has the greatest amount of colour which is why it’s used for

modifying photographs and for creating concept art, and photo-realistic images in general.

The pixilation happens when trying to stretch a raster image, this is because you are stretching the

individual pixel, and this makes the overall quality much worse and creates a blurry and distorted

appearance. Another raster drawing package is paint which is free compared to the expensive

Photoshop package from adobe. Paint does not allow for a much freedom as Photoshop does with

how you create an image and does not allow for as many colours it uses an 8 bit instead of the

Photoshop’s 24 bit. And does not allow for Photo perfect modification like Photoshop does. Though

it does come free when you purchase a PC. Photoshop has a greater amount of tool as the user’s

disposal, which of course gives it more freedom to the user. Paint gives the necessary amount of tool

to create and modify some images, but does not give the overall professional look when finished

this is why Photoshop is used in the big media industry to air brush models and such to create

professional looking images worthy for publication in magazines.

Raster images use different file formats to other types of images such as vector.

The Raster file types are. Gif, Tif, BMP, JPEG and PSD these are the raster file

types, Photoshop file type is a PSD and can hold a greater amount of colour 24

bit which is 16 million different shades of colour.

Vector and raster Graphics

Vector drawing packages such as adobe illustrator are mostly used to create graphics which can be

used for logos or cartoons another adobe program for vector animation is Adobe flash this allows

the user to create vector images/characters but then allows animation and also creation of websites.

Vector lines are made up for a formula instead of pixels like the raster images this allows vector

images to be stretched as far as you want without pixilation this is ideal for posters and billboard

adverts and most importantly for logo creation because after they are made they can be sized to fit

anything that you need.

Flash is greater for making vector images to animate rather than making logos, this is because flash

has more animation type tools at the users disposal whereas illustrator has a lot more logo and

shape creating tools with additional graphic layers so that you can overlap colours, shapes and

images to create any graphic that you could imagine. They both require an equal amount of skill to

master, vector images cannot use as many colours as bitmap and mostly only use solid colours,

which is great if you’re creating cartoons or solid colour graphics.

Metafiles use both vector and raster file types into a metafile which uses the best of both. A

common use for these file types is for operating systems and computer graphics, so you can

minimize space use by combining the types of graphic files (raster and vector).

File extensions and their uses:

All file types fit different uses and purposes some are for print while other are used on the web, each

file type has a role.

AI files: Adobe illustrator files- are best used for printing as they are vector images and stretch

without getting pixelated or becoming blurry/ unreadable.

PSD files: Photoshop files- PSD is a Photoshop file therefore is a raster/bitmap file extension that is

used for raster images that are created using Adobe’s Photoshop software.

Tiff file- Tagged images file format (TIFF) is used mainly to exchange documents between different

applications and different computer platforms. This file format supports Photoshop quite heavily

and supports bitmap and raster images.

PNG- Portable network graphic employs lossless compression and was originally created to be and

updated and better version of the GIF file format, these files are perfect for uploading to the web

because they are a network file.

BMP- this is a bitmap file format and is used to store 2D bitmap and raster images, independently on

a display device. It’s capable of storing a 2D image with random width, height and resolution. And

both greyscale and colour images.

Vector and raster Graphics