Slide 1 Graphics

Slide 2 Graphics A graphics package is a general purpose package used to draw pictures (graphics). Once produced, these can be saved or printed out. Like all information displayed on a computer monitor, graphics are made up of tiny dots called pixels. When the pixels are small, we say that the picture has a high resolution because it is clearly defined and of good quality. When the pixels are larger, we say that the resolution is low, (see Low Level Machine notes).

Slide 3 Features of Graphics Packages As well as all the features of general purpose packages, graphics packages have some other features: 1.Draw Graphic The facility to control the cursor on the screen to draw a shape. The cursor can be controlled using a mouse, joystick, graphics tablet, the keyboard, a light pen or a trackball. 2.Enter text The facility to add text to a graphic as a label, heading or explanation of the diagram. 3.Cropping a graphic Cropping means cutting the graphic leaving on the part of the picture you want. Almost like using a pair of scissors. This means you can’t get back the part you have cropped off.

Slide 4 3.Tool selection The user selects the drawing tools by selecting the relevant icon. These tools include: line, circle, rectangle, arcs, shading etc and are shown as a series of icons in a palate at the side of the screen. 4.Altering tool attributes Once selected the user can change the colour and width of the line the tool will draw.

Slide 5 6.Rotate graphic The user can turn a graphic through any number of degrees. 5.Scale graphic This allows the user to change the size of the graphic.

Slide 6 Paint and Draw Graphics packages can be divided into 2 categories, paint and draw. Draw Packages These define graphics as objects on the screen. Because each object is separately defined they can be ‘layered’ on top of each other and moved apart again without affecting the shapes.

Slide 7 Paint Packages These produce graphics by changing the colour of the screens pixels. There is only one ‘layer’ of picture so that if two shapes overlap on the screen, the second shape overwrites the first.

Slide 8 Animation Computer graphics can also be used to produce moving images known as animations. These used in film and television as well as in games and tutorials. Many of the special effects in films today are achieved using computer animations.

Slide 9 Scanning a Graphic A graphic image that has already been created on paper or in a book can be loaded onto the computer using a scanner. Using the scanner software the resolution, number of bits used to store the graphic, can be set. The image can then be changed eg Cropped, rotated, adjust colour