Boyer, V.Bourdin, J.J.2015-02-162015-02-1619991467-8659https://doi.org/10.1111/1467-8659.00358Straight line's scan conversion and drawing is a major field in computer graphics. Algorithm's time computation is very important. Nowadays, most of research papers suggest improvements of the DDA method that was first presented by J. Bresenham. But other approaches exist as well like combinatory analysis and linguistic methods. Both of them use multiple string copies that slow down the efficiency of the algorithms. This paper proposes a new algorithm based on a careful analysis of the line segments' properties some of them previously unused. Our algorithm is proved significantly faster than previously published ones.Fast Lines: a Span by Span Method10.1111/1467-8659.00358377-384