An Efficient Euclidean Distance Transform

Within image analysis the distance transform has many applications. The distance transform measures the distance of each object point from the nearest boundary. For ease of computation, a commonly used approximate algorithm is the chamfer distance transform. This paper presents an efficient linear-time algorithm for calculating the true Euclidean distance-squared of each point from the nearest boundary. It works by performing a 1D distance transform on each row of the image, and then combines the results in each column. It is shown that the Euclidean distance squared transform requires fewer computations than the commonly used 5x5 chamfer transform.

• Type: Conference
• Year: 2004
• Where: IWCIA
• Authors: Donald G. Bailey
• Keywords: Chamfer Distance Transform, Distance Transform, IWCIA 2004, Nearest Boundary