BTec Level 3Extended Diploma in Creative Media Production

HA1 - Technical File – Emily Davis

Raster and Vector Images

BTec Level 3Extended Diploma in Creative Media Production

Raster ImagesIn computer graphics a raster graphics image or bitmap, is a data structure representing a generally rectangle grid of pixels or points of colour viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats. The printing and prepress industries know raster graphics as contones. Raster graphics are resolution dependent. They cannot scale up to an arbitrary resolution without loss of quality. This property contrasts with the capabilities of vector graphics, which easily scale up to the quality of the device rendering them. Raster-based image editors, such as Painter, Photoshop, MS Paint, and GIMP, revolve around editing pixels, unlike vector-based image. A raster image editor works by manipulating each individual pixel, whereas most pixel-based image editors work using the RGB colour model, but some also allow the use of other colour models such as the CMYK colour model. The raster image takes a wide variety of formats, including the familiar .gif, .jpg, and .bmp. The pixels form points of colour which create an overall finished image. When a raster image is viewed, the pixels usually smooth out visually for the user, who sees a photograph or drawing. Depending on resolution, some raster images can be enlarged to very large sizes, while others quickly become difficult to see. The smaller the resolution, the smaller the digital image file.

The smiley face in the top left corner is a bitmap image. When enlarged, individual pixels appear as squares. Zooming in further, they can be analyzed, with their colours constructed by adding the values for red, green and blue.

Vector Images

Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon(s) which are all based on mathematical equations, to represent images in computer graphics.

Vector graphics is the representation of images as an array of pixels, as is typically used for the representation of photographic images. Vector graphics are stored as mathematical expressions as opposed to bit mapped graphics which are stored as a series of mapped dots, also known as pixels. A vector graphics program uses these mathematical formulas to construct the screen image, building the best quality image possible, given the screen resolution. The mathematical formulas determine where the pixels that make up the image should be placed for the best results when displaying the image. Since these formulas can produce an image scalable to any size and detail, the quality of the image is limited only by the resolution of the display, and the file size of vector data generating the image stays the same. Printing the image to paper will give a sharper, higher resolution output than printing it to the screen but can use exactly the same vector data file.

BTec Level 3Extended Diploma in Creative Media Production

HA1 - Technical File – Raster and Vector Images

Anti aliasing or sometimes known as anti-aliasing, refers to methods of eliminating or reducing these unwanted artefacts. In the context of raster images, anti aliasing refers to the reduction of the jagged borders between colours. In the context of vector images

Here is a simple image that is still complex enough to show jaggiest when rendered. This is even more noticeable in the detail image.Anti-Aliasing is a term used lots when

selling graphics cards. It is a method of fooling the eye that a jagged edge is really smooth and is often referred in games. Monitors are capable of producing nearly perfect straight lines either horizontally or vertically, but when it comes to diagonal lines of any angle your monitor is not capable of producing a line without some jagged edge. This is because your screen is made up of pixels in a grid formation, so this is where anti aliased comes in.

Resolution

Image resolution is measured in picture elements which are called pixels. Basically resolution quantifies how close lines can be to each other and still be visibly resolved. Resolution is sometimes identified by the width and height of the image as well as the total number of pixels in the image.

A computer screen is most probably set at a particular resolution as well because the larger the screen, the larger you likely have your screen resolution set.

It makes the images edges allot smoother rather than jagged and look unfinished. Just like in this example pictures the higher the ppi the better the resolution of the image.

Aspect Ratio

Aspect ratio is a measurement of the proportion of your image. The largest side divided by the smallest side of your image will give you your aspect ratio. Its like if you have a photograph and you want to give it a perfect crop on either side, or if you want to squash the top of the picture then you change the aspect ratio on either side to get the exact part of the picture you want cut out. All you can do with aspect ratio is drag either one of the sides of the picture you want. It is the width and height of a shape. You can calculate the image dimension in pixels for the total number of aspect ratio for a picture or anything you want to crop.

Gif - Graphics Interchange FormatIt allows a single image to move weather its real picture or animation.It can be moving or animated its used and very good for simple graphics which don't much detail. GIF uses the 2D raster images. One version of a gif allows a short sequence of images within a single GIF file.

JPEG - Joint Photographic Experts GroupJPEG is an image file and is a popular way to compress and change word or excel sheets to see it as just an image. Both GIFs and JPEGs are the two most popular forms of image compression used on web sites. Research has indicated JPEG is currently the most popular form of image compression used on the World Wide Web.

Tiff - Tagged Image File Format Its popular among graphic artists, the publishing industry. They are used for storing very large and high quality images. This file format is used for manipulation programs, desktop publishing and 3-D imaging. Other things that use TIFF is optical recognition software and scanning and faxing applications.

Eps - Encapsulated PostScript This is a standard graphics file format for exchanging images, drawings like logos or maps, or even layouts of complete pages. An EPS file can contain any combination of text, graphics and images. Since it is actually a PostScript file, it is one of the most versatile file formats that are available. The files usually contain a small preview image that is used to visualize the content of the file.

PSD - Photoshop DocumentA PSD file stores an image with support for most imaging options available in Photoshop, which include layers, transparency, text, alpha channels and spot colours and clipping paths.

PDF - Portable Document FormatThis file format is developed by Adobe Systems. It captures formatting information from a variety of desktop publishing applications making it possible to send formatted documents and have them appear on the a monitor or printer as they are meant to look and be.

Colour Models

A colour model is an orderly system for creating a whole range of colours from a small set of primary colours. There are two types of colour models, those that are subtractive and those that are additive. Additive colour models use light to display colour while subtractive models use printing inks.

There are several established colour models used in computer graphics, but the two most common are the RGB model Red-Green-Blue for computer display and the CMYK model which is Cyan-Magenta-Yellow-black which is for printing.

Since additive colour models display colour as a result of light being transmitted the total absence of light would be perceived as black. Subtractive colour models display colour as a result of light being absorbed by the printing inks. As more ink is added, less and less light is reflected. Where there is a total absence of ink the resulting light being reflected from a white surface would be perceived as white.

Adobe Photoshop

Its a photo editing software, it can be used to manipulate photographs and to create images that improve reality/real images. People use it for their own photos or for professional uses if they need it for models.

There are four sections:Photoshop's toolbox, including the Options Palette settings for each toolThe menu commands - including every item of every dialogThe floating palettes - including the function that each palette provides as well as the ramifications of every value and palette submenu

Its full of ways to make photos you already have look completely different by changing all the effects colours, you make a picture look like two separate ones when your finished.

Adobe Illustrator

One of the main features of illustrator is to allow you to add effects and create complex designs with text. It helps you make anything by just drawing a shape then manipulating it into a logo. It lets you combine shapes and graphics to create anything you want to. Its one of the main adobe software's next to Photoshop because of the skills you can do on it.

The main things that you can learn and do are:•Create simple and freeform shapes•Create logos using simple shapes and custom paths•Enhance logo text•Manipulate body text•Create an advertisement

Adobe InDesign

It is used for making any document that needs some creative layout. It can help make posters, newspapers, flyers and magazines look more interesting and creative to make them more memorable or appealing. It offers all kinds of features to modify your text and images, which work together to help you create a unique and professional design.

When it comes to web design and development, Adobe Indesign is one of the best programs to use. There are plenty of walk through instructions and videos and loads of tools to use and skills to learn so you can be creative and make loads of things for business or just fun.