The Euclidean Distance Transform(EDT)converts a binary image into one where each pixel has a value equal to its Euclidean distance to the nearest foreground.It has important applications in image analysis and computer vision.This paper gives an algorithm for complete Euclidean distance transformation on the binary image on the basis of the contour scanning.In the suggested algorithm all the pixels are classified and the ones which neither are characteristic pixel nor have characteristic pixels in 4-neighbors are marked.For the marked pixel

scan its contour form inner to outer

find its nearest characteristic pixel and compute their Euclidean distance.The exact distances are obtained.The requirement of time are analyzed briefly

some testing data produced in running the implementation are illustrated.The result shows that the algorithm runs fast

the requirements of space and time are satisfying in the present hardware condition

and it is an effective and enormous applied distance transformation algorithm.