4.2 GRAPHICS SOFTWARE PAINTING AND DRAWING SOFTWARE Do you use any graphics programs? If so, what for? The quality of a bitmap image depends on the total number of pixels, i.e the resolution, and the amount of information in each pixel, often called colour depth. Microsoft Paint is a simple raster graphics editor included in all versions of Microsoft Windows. ONLINE RESOURCES CAD Digital mapping brush: pennello canvas: tela dot: punto grid: griglia layer: strato Both painting and drawing software are examples of graphics programs used to create, manage and edit 2-dimension digital images. Microsoft Paint is a basic program for non-professional users. Another popular free program for general users is Krita. Painting software Painting software is pixel-based software which allows the user to create and save a series of coloured dots, called pixels, in a bitmap file. Bitmap-based images, also called raster graphics, are therefore made up of pixels in a grid like a mosaic, and each pixel, or bit, holds a specific colour value. The most common bitmapbased formats are: JPEG, GIF, TIFF, PNG, PICT and BMP. Bitmap-based images have a fixed resolution and cannot be resized without losing image quality. Moreover, as the image files tend to be rather large, they are often compressed to reduce their size. Bitmaps can be stored, reused, and converted into other bitmap formats very easily. It can take thousands of dots to make up a whole picture and to edit the image, each dot needs to be altered individually, although there are a lot of different tools to make it easier. The general features of a painting program are the following: a palette from which the user can choose the colour; pens and brushes with different styles and line thickness; colour fill tools; spray cans and eraser tools; cut, copy and paste. Drawing software Drawing software is vector-based, or object-based, software. Vector graphics are made up of many individual objects which are defined by mathematical formulas and individual properties such as colour, fill and outline. Although the result is still a bitmap, i.e. a series of dots, the image consists of separate lines and shapes, which are the objects, and is saved as coordinates and equations, making the file size a lot smaller. The image is edited by manipulating the objects. For example, if you want to draw a circle, you only need four sets of values: the x,y coordinates of the centre, the stroke line style, the radius of the circle, and the fill colour (optional). The big advantage of the vector approach is scalability: one formula or set of formulas can represent many sizes of the object. Therefore, vector graphics are resolution independent and easy to modify by simply changing the sets of values. AI (Adobe Illustrator) is a common drawing program. 164 THE USES OF COMPUTERS