Q1Computer Graphics and Multimedia
Question
Define Scan Conversion.
Answer
Scan conversion is the process of converting geometric primitives (lines, circles, polygons) defined in world coordinates into discrete pixel representations on a raster display.
Scan conversion (also called rasterization) is the process of determining the set of pixel locations that best approximate a geometric primitive (such as a line, circle, ellipse, or polygon) on a raster display device. It bridges the gap between the mathematical, continuous description of graphics objects and the discrete pixel grid of a display.
For example, scan converting a line segment involves finding all the pixels that lie on or close to the ideal mathematical line between two endpoints. Key scan conversion algorithms include DDA (Digital Differential Analyzer), Bresenham's line algorithm (for lines), midpoint circle algorithm (for circles), and scan-line fill algorithm (for polygons).