Graphics are pictures, still and moving, such as illustrations, photographs, animations, and films. In 1963, Ivan Sutherland, a graduate student at MIT, created the first graphics program for small computers. Sutherland’s Sketchpad, which ran on a minicomputer and used a light pen to draw lines on a screen, was the first of a long line of graphics software programs that have revolutionized commercial and, to some extent, noncommercial illustration and design.Early Painting and Drawing ProgramsIn the early days of personal computing, software developers created two types of programs for producing computer graphics. Bitmap-based or raster image-based graphics programs, commonly called painting programs, allowed users to create pictures by changing the pixels, or picture elements, on the screen from white to black. Object-based or vector-based graphics programs, commonly called drawing programs, allowed users to construct pictures by creating, editing, and combining mathematically defined geometric shapes. Eventually, color and grayscale versions of both painting and drawing programs were developed. Early painting programs were great for free-form sketching, but because of their low resolution, corresponding to the limited dot-per-inch (dpi) resolutions of computer screens, they tended to produce work with a jagged, or pixelated, look along slopes or curves.Developments in Painting and Drawing ProgramsThe pixelization problem in painting programs was resolved in two ways. First, as the RAM and storage capacities of personal computers grew, raster image-processing programs were created that could handle images with a greater number of dots per inch. Today’s high-end raster image programs can handle full-screen images at 2400 dpi or higher in 16.7 million different colors. Another solution to the pixelization problem was the development of antialiasing, whereby pixels along the edge of an image are progressively lightened or da...
