Abstract: Isoline map vectorization has been widely used in geology, geophysics,
geographical information systems, etc. There are still some shortcomings of the computer
automatic recognition in practical application. This paper presents an interactive isoline map
vectorization algorithm by improving the isoline map vectorization algorithm based on the
circular track. The isoline intervals tracking algorithm makes up for the shortcomings of computer
automatic recognition by manual intervention, ensures the correctness of the tracking, fits for the
grayscale isoline image vectorization. This algorithm is practical and efficient.

Key words: computer applications, Isoline, image vectorization