GRAPHICS SOFTWARE 11 PAINTING AND DRAWING SOFTWARE Answer these questions. a. What application do you use to draw on your computer? Do you know how it works? b. What effects can you apply on a photo by using the software of your smartphone? c. Do you know how digital maps work? brush: pennello canvas: tela dot: punto grid: griglia layer: strato The quality of a bitmap image depends on the total number of pixels, i.e. resolution, and the amount of information in each pixel, often called colour depth. Both painting and drawing software are examples of graphics programs used to create, manage and edit 2-dimension digital images. Painting software is pixel-based software which allows the user to create and save a series of coloured dots, called pixels, in a file called bitmap. 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 bitmap-based 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. To edit the image, each dot needs to be altered individually, although there are a lot of different tools to make it easier. In fact, ready-made letters, numbers, images and symbols are provided by the operating system, or made available through image collections like Clip-art. 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. Microsoft Paint is a basic program for non-professional users. Other free programs for general users are Paint. Net and MyPaint. Drawing software, on the other hand, is vector-based, or object-based, software. Vector graphics are made up of many individual objects which are defined by mathematical formulae 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 vector approach is scalability: one formula or set of formulae 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) and CDR (CorelDraw) are two common vector formats. 162 Module 4 FLOWCHARTING