Unit 54 Digital

Graphics

Raster Graphics

Raster graphics are digital images created or captured (for example, by scanning in a photo) as a set of samples of a given

space. A raster is a grid of x and y coordinates on a display space.

When it comes to creating graphics, designers must choose to express their creativity using either vector or raster graphics.

Advantages:

The geographic location of each cell is implied by its position in the cell matrix. Accordingly, other than an origin point, e.g.

bottom left corner, no geographic coordinates are stored.

Due to the nature of the data storage technique data analysis is usually easy to program and quick to perform.

The inherent nature of raster maps, e.g. one attribute maps, is ideally suited for mathematical modeling and quantitative

analysis.

Discrete data, e.g. forestry stands, is accommodated equally well as continuous data, e.g. elevation data, and facilitates the

integrating of the two data types.

Grid-cell systems are very compatible with raster-based output devices, e.g. electrostatic plotters, graphic terminals.

Disadvantages:

The cell size determines the resolution at which the data is represented.

It is especially difficult to adequately represent linear features depending on the cell resolution. Accordingly, network linkages

are difficult to establish.

Processing of associated attribute data may be cumbersome if large amounts of data exist. Raster maps inherently reflect

only one attribute or characteristic for an area.

Since most input data is in vector form, data must undergo vector-to-raster conversion. Besides increased processing

requirements this may introduce data integrity concerns due to generalization and choice of inappropriate cell size.

Most output maps from grid-cell systems do not conform to high-quality cartographic needs. A raster graphics editor is

a computer program that allows users to paint and edit pictures interactively on the computer screen and save them in one of

many popular "bitmap" or "raster" formats such as JPEG, PNG, GIF and TIFF. A raster graphics editor supports a certain

repertoire of image editing operations. Some editors specialize in the editing of (digital) photographs such as the popular

Adobe Photoshop or Raw Therapee, while others are more geared to artist-created illustrations, like the Adobe Fireworks.

Usually an image viewer is preferred over a raster graphics editor for viewing images.

Raster Graphics

Vector graphics Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygons—all of which are based on

mathematical expressions—to represent images in computer graphics.

Each of the graphic types has their own particular strengths and limitations and understanding these differences is essential to

achieving the best results. Vector images are constructed of lines (also called paths) and are created by software programs that use

mathematical calculation to determine size, shape and color of each line. By combining paths that are straight or curved and various

colors and shading very detailed illustrations can be created. Because the image is created using mathematical precision using

programs like Adobe Illustrator or CorelDraw, the resulting files can easily be resized larger or smaller without any loss in image quality.

In this example we have enlarged a vector version of our logo.

Advantages

The important point of vector graphics is the power of scalability. If we try to enlarge the pixel based image, it only enlarge the size of the

squares making up the image area and pixel based image will be jagged. If we consider the vector image, it will remain in its best

quality.

Data can be represented in original resolution without generalization.

Graphical outputs of the images are more pleasing than the created as raster image.

In some data like hard copy maps, no data conversion is needed.

Every lines in a vector graphics represents different and distinct object so each object can be edited as many times. For example, if we

take art file with a circle in back ground. It can be opened any time even days later and change circle to a square. It will be at their best

quality.

Another very important reason of using vector graphics rather than raster is their size. Vector objects are much smaller than raster

image format. If we have full size image to update, the vector file might only take few kilobytes of space on your system, where the

same image in medium resolution bitmap format might not place on CD ROM.

Disadvantages

The drawing image containing trapping information can only be scaled up to 20% larger or smaller.

Thin lines in vector images may disappear if we reduce the size too much.

The very important disadvantage of vector image is time consuming and also specific talent must be needed to create it.

Photographs cannot be taken as vector images. It must be drawn by the artist, and must be editing in software like adobe illustrator.

The vector images are not as cost effective as raster images.

The location of each vector, need to be stored separately.

Algorithms for manipulative and analysis functions are complex and may be processing intensive and it limits the functionality for larger

data sets.

Vector graphics

JPEGS

JPG files, also known as JPEG files, are a common file format for digital photos and other digital graphics. When JPG files are

saved, they use "lossy" compression, meaning image quality is lost as file size decreases. JPEG stands for Joint

Photographic Experts Group, the committee that created the file type. JPG files have the file extension .jpg or .jpeg. They are

the most common file type for images taken with digital cameras, and widely used for photos and other graphics used on

websites.

JPGs allow for some degree of file size reduction without losing too much image quality. However, as file sizes get very low,

JPG images will become "muddy." When saving photos and other images as JPG files for the web, email and other uses, you

must decide on this tradeoff between qualities and file size.

Advantages of the JPEG Format

Large compression ratios = shorter file transfer time

Full-colour information

Great for photographs, graphic artwork, banner ads, etc.

Disadvantages of JPEG Format

Loss of image quality

Sharp edges tend to come out blurry

Longer page load time than the GIF Format

JPEGS

Tagged Image File Format

TIFF is a computer file format for storing raster graphics images, popular among graphic artists, the publishing industry, and both amateur and professional photographers in general.

The TIFF format is widely supported by image-manipulation applications, by publishing and page layout applications, and by scanning, faxing, word processing, optical character recognition and other applications. Adobe Systems, which acquired Aldus, now holds the copyright to the TIFF specification.

Advantages

Uncompressed image retains maximum amount of image data from the camera.

Can be compressed to reduce file sizes using mathematical algorithms such as ZIP or TAR without loss of image data

Can also use lossy compression such as JPG algorithms to reduce file size

Recognised format by most computers, cross compatible with both MAC and PC’s

Standard format for printing either at home or dedicated Photo lab.

Can embed colour space profiles as well as ITPC Metadata

Disadvantage

Large file sizes, around 20mb for a 10 megapixel image, so larger storages devices needed for long term archival use.

Good specification computer needed to process and load images.

Most website and online images galleries do not support tiff uploading.

Slow speeds when transferring to online galleries that do support TIFF files

Tagged Image File Format

PSD

This is file created in Adobe Photoshop during design process of each template. This file is similar to ordinary JPEG or PNG image, but it's editable. In example, unlike ordinary image files (JPG, PNG, GIF), PSD files can be layered. In example, the first layer contain top menu, the second layer contains logo, and the third layer contains text, and so on... Text in PSD files can be edited through Photoshop, simply by selecting and editing the existing textual layer. You can change font, text colour, etc.

To open and edit the PSD file, you need Adobe Photoshop. This software is expensive, but there are also free alternatives, such as GIMP. However, we can't guarantee that our PSD files work well in these alternative programs, as they are created in the original Photoshop.

Advantages

The layers are preserved when a file is saved using the PSD file format.

You can go back, at any time, to make changes to the layers.

Disadvantages

Do not distribute PSD files unless you are doing a Photoshop tutorial or something. Photoshop files are large.

They can be compressed (RLE encoded) but often this compression does not yield a file that is much smaller.

PSD

AI (Adobe Illustrator) Adobe Illustrator is a program used by both artists and graphic designers to create

vector images. These images will then be used for company logos, promotional uses or even personal work, both in print and digital form.

The possibilities with Adobe Illustrator are endless, just download it and see what a new dimension all your layouts and designs will take. Once you master the drawing tools and the basics there is no looking back. And if you have worked with Photoshop in the past, it will be even easier since the palates and commands are quiet similar.

Advantages

It allows you more flexibility with customizing the workspace. It comes with a user interface that allows custom viewing and enables space saving.

Illustrator gives more control over text and its formatting with options like paragraph composing and OpenType fonts

Using illustrator increases productivity as it allows for in-panel editing and use of multiple artboards at a time.

As it is a vector based program it allows the creation of graphics that are scalable to any extent without losing resolution, with crisp and sharp lines that are perfect for print.

Illustrator files are comparatively small in size so allow easy sharing, mailing and use.

Disadvantage

Since it is a design software some amount of skill or training is require to master it. A good idea is to check out the numerous tutorials that are available by adobe itself or spend some time with the tools this program is loaded with to master it.

To create photo realistic drawing the user must have oodles of patience and a keen eye for detail.

AI (Adobe Illustrator)

3DS 3DS is one of the file formats used by the Autodesk 3ds Max 3D modelling,

animation and rendering software.

Advantages

Great Library of GamesNice exterior designBetter Battery Life with XLControl StickFriend's ListStreet pass PlazaSwap noteeShopPlay games in 3DInterior/Exterior CamerasMii Maker

Disadvantages

Short Battery Life with original 3DSBad U/INo Gamertags(Miiverse will take care of that)No Party Chat or proper Messaging SystemNo Achievement SystemNo GBA games in eShopAlot of overpriced games in eShopLimitations with Folder SystemGame saves tied to game Cartridges(Physical copies)No Linked account system

3DS

Antialiasing

In computer graphics, antialiasing is a software

technique for diminishing jaggies - stairstep-like lines

that should be smooth. Jaggies occur because the

output device, the monitor or printer, doesn't have a

high enough resolution to represent a smooth line.

Resolution

Resolution is the quality of being determined or

resolute.

File format

A file format is a standard way that information is

encoded for storage in a computer file. It specifies

how bits are used to encode information in a digital

storage medium. File formats may be either

proprietary or free and may be either unpublished or

open.

Application

This is the action of putting something into operation.

Adobe Photoshop

Adobe Photoshop is a raster graphics editor

developed and published by Adobe Systems for

Windows and OS X. Photoshop was created in 1988

by Thomas and John Knoll. Since then, it has

become the de facto industry standard in raster

graphics editing, such that the terms "photo

shopping" and "Photoshop contest" were born.

Adobe InDesign

Adobe InDesign is a desktop publishing software

application produced by AdobeSystems. It can be

used to create works such as posters, flyers,

brochures, magazines, newspapers and

books. InDesign can also publish content suitable for

tablet devices in conjunction with Adobe Digital

Publishing Suite.