Assessment 2 & 3 – Graphics

Stuart Matthews
Assessment 2 & 3 – Graphics

Graphics and images can be used to convey information, add text for headlines, buttons etc, and diagrams for information and to change the look of the document. Using graphics and images means that a presentation can be understood despite language barriers, making it multilingual. Graphic and images come in two different formats, vectors and bitmaps. Vector files are made from lines which means that there is no distortion when the size of the image is increased. Bitmap files are made from pixels, the more pixels the better the resolution. Bitmap file types have a .bmp extension, are the most common and are a windows device. Other file types are used for compressing bitmap files which can be very large and therefore inappropriate for some types of multimedia applications like websites. Application for creating image and graphic files include Paint, PaintShop Pro, Photoshop (bitmap) and Fireworks, Coreldraw (vector). Most of these programs have their own files type and can also open other files. These applications have advantages and disadvantages, the main disadvantage is the price of the software, which can be very expensive but the advantage of the higher price software is the number of effects and options for manipulating images that are available.

Bitmap packages work by dividing the image into a grid of millions of cells and assigns a colour, lightness or darkness to every single cell or ‘pixel’. Once a line or text has been drawn on the canvas it cannot be edited without undoing and starting again. Because the image is made up of single pixels the image cannot be enlarged without enlarging the pixels making the image look ‘jaggy’ with rough square edges. One of the most popular bitmap applications is PhotoShop which has many tools and options for creating, editing and optimizing images.

Vector packages work by treating images as a collection of shapes and lines and stores them as mathematical equations to determine how the image should look. Since these formulas are used to produce the image there is no distortion when the image is rescaled unlike with bitmap images. However as the computer screen is displayed the same way as a bitmap file, using pixels, when zoomed in on the vector image there will still be jagged edges although the edge is perfectly smooth.

The main function of graphics software is to make images ready for publishing on the internet. Before importing files to authoring or web development software files should be compressed in order to reduce files sizes. Photographs can be very large and must be manipulated in order to make them web friendly, things that can be done to reduce file size include cropping the image to only the part that is needed and reducing picture quality. Most software applications will have the option to compress file types and allow the user to change the options for the exported image. The user can reduce the quality, number of colours used and see the final size of the optimized image. For use on the web most images will be exported as either a jpeg or gif file. Files sizes are important when developing an application for the internet because the bigger the file the longer it will take the user to be able to view it. This might not be a problem with broadband connections but users with slower modems will find they have to wait to see large files displayed. The smaller the file sizes the smaller the size of the final production. If the image is to be printed then the highest quality possible should be used to get the best resolution.

Graphics applications have many tools available to assist the user in creating and editing images. Layers allow the user to work on different elements on different layers without disturbing other elements and add effects and styles to one part of image only. Effects such as shadows, glows, bevels, overlays and strokes can be used to quickly change the appearance of layers content. Filters can also be applied to add special effects to a layer like artistic filters that replicate natural or tradition media effects, blur filters and texture filters. Slice tools can be used to divide an image into functional areas such as hotspots for html links and rollover effects. Shapes like rectangles, ovals and stars can easily be created from a variety of shape tools and predrawn shapes. The pen tool allows the users to create straight lines and curves with more precision than other tools. Pen tools can also be used to create ‘paths’ for text to follow. Transparency is possible in a number of file formats, the most popular for use on the web is gif files. Transparent images can be used on sites as spacers and to add corners and curves to tables that usually look square. Other uses for transparency include adding gradients either to images or web pages.

3D rendering software allows the creations of 2D and 3D content with tools for modelling, lighting, texturing and rendering allowing the user to create much more realistic pictures and animations.