Software

Read the description on the next slide. Can you picture the scene?

There is a steep road curving upwards on the right and an even steeper one going downwards on the left. You can see how steep it is by looking at the angle of the car going down it. There are three trees, all quite dark, with broad tops to give shade on hot days. The village is built in terracotta colours, and the buildings are quite square with sloping roofs. The houses have quite small windows and most of the windows have shutters as well. At the top right, just at the top of the hill, there is a round building that looks as if it could have been a watchtower many years ago. The distant scenery is not easy to see, because it’s quite misty and out of focus, but it looks rural and seems to be fields and mountains. There is ivy or some other sort of creeper growing up the walls.

That was only 155 words, but it’s certainly clearer to get an image of this Italian village by looking at the photograph.

Pictures can be used to make something look attractive or to make it easier to understand.

A graphics program enables you to create images using a variety of tools including lines, shapes and fills. Images can also be captured using devices such as a scanner or a digital camera and then manipulated using a range of effects and filters. Clip-art libraries can also be used to search for images. There are two types of graphics software – drawing and paint programs. Drawing programs use vector graphics whilst paint and photo editing programs use bitmap graphics.

A bitmap image is made up of thousands of dots or pixels. The higher the number of dots per inch (dpi), the better the picture quality (resolution). The higher the number of dpi, the bigger the file size of the image. Images designed to be printed need higher resolutions than those designed to be viewed on screen.

If you make bitmap images larger, the computer just makes each dot larger, and so you get jagged edges rather than smooth lines. x 8 The jagged edges are filled with shades of grey. Bitmap packages use anti-aliasing to try to overcome this. The colours are blended at the edges to fool your eye into seeing a smooth line.

Photographs are often stored as bitmaps. Graphics software can be used to: clean up and remove defects on photographs apply effects to change the appearance of a picture improve on nature – get rid of the model’s spot or add shiny highlights to a car.

A vector image is made up of shapes (also known as objects). The shapes are made of lines drawn between points. Shapes can be filled with single colours, or patterns made from several colours. Each shape can be dragged around the page, resized or re- coloured. The shapes are drawn mathematically, so changing the size does not affect the quality.

Animations are made up of a series of images played in sequence. If they are played back quickly, they fool the human eye into thinking they are moving. Animation packages can help by inbetweening – you draw the start and end frames and the computer generates the ones in between.

Graphics software can be used to: create accurate drawings use specialist object libraries, such as furniture, windows and doors for designing houses create 3D images of new buildings so that people can “walk through” them recreate old buildings from their ruins to give an impression of what they would have been like make images that give visual impact to advertisements.

Summary Graphics can be bitmap or vector. Bitmaps are made up of tiny dots called pixels. Bitmaps tend to lose quality if enlarged. Vector graphics are made up of shapes (also known as objects). Each object is drawn mathematically between points. Vectors can be enlarged without losing quality. Bitmaps tend to be used for photographs. Vectors tend to be used for graphics such as clip art. Animations are made up of sequences of pictures, each slightly different to the one before.