A Fast Exact Euclidean Distance Transform Algorithm

Euclidean distance transform is widely used in many applications of image analysis and processing. Traditional algorithms are time-consuming and difficult to realize. This paper proposes a novel fast distance transform algorithm. Firstly, mark each foreground´s nearest background pixel´s position in the row and column, and then use the marks scan the foreground area and figure out the first foreground pixel distance transform information, According to the first pixel´ information, design four small regions for its 4-adjacent foreground pixel and also based on the marks search out each adjacent foreground pixel´s nearest background pixel. As the region growing, iteratively process each adjacent pixel until all the foreground pixels been resolved. Our algorithm has high efficiency and is simple to implement. Experiments show that comparing to the existing boundary striping and contour tracking algorithm, our algorithm demonstrates a significant improvement in time and space consumption.