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Exponential Hermite Snake



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Plugin for ImageJ

[Version 04.02.2014]

Exponential Hermite Snake Plugin

Image analysis tool

Written by Virginie Uhlmann at the Biomedical Image Group (BIG), EPFL, Switzerland

Exponential Hermite Snake before convergence.

Exponential Hermite Snake after convergence.

Figure 1. Exponential Hermite Snake at initialization.

Figure 2. Exponential Hermite Snake after convergence.


This software implements an active contour (a.k.a snake) constructed with new exponential B-splines inspired from the cubic Hermite splines. It provides a direct control over the tangents of the parameterized contour, which is absent in traditional spline-based active contours. The new basis functions have been designed to perfectly reproduce elliptical and circular shapes, which makes the model well-suited to outlining blob-like objects.


Technical Explanations

We introduce a class of active contours built using a novel kind of exponential B-spline basis functions. The snakes family that stems from them have two main features that make it well-suited to the analysis of bioimages. Firstly, it is built using two complementary basis functions, a construction inspired from Hermite interpolation that grants direct control both on the curve and on its tangent field. Secondly, it has ellipse-reproducing capabilities. Our model actually uses the shortest possible functions that have the Hermite property, satisfy the partition of unity, and reproduce ellipses.

Active contour algorithms consist of two steps. The snake is first initialized by the user, and then the curve is made to evolve on the image through the optimization of a cost functional (or snake energy). In the present example, the snake energy can be tuned to be attracted to edges or ridges.


ImageJ prerequirement

The software provided here is a plugin for ImageJ, a general purpose image-processing and image-analysis package. ImageJ has a public domain licence; it runs on several plateforms: Unix, Linux, Windows, Mac OS 9 and Mac OS X. It doesn't take more than a couple of minutes to install.

Download and install

To install the plugin download the ExpHSnake.jar file and put it in the plugins folder of ImageJ (ImageJ/plugins/). The Exponential Hermite Snake plugin also requires some external libraries that have been regrouped in the following archive file. The archive should be uncompressed, and the elements it contains should be placed into the jars folder of the plugins folder of ImageJ (ImageJ/plugins/jars/).

User manual

Conditions of use

You'll be free to use this software for research purposes, but you must not transmit and distribute it without our consent. In addition, you undertake to include a citation to the associated papers whenever you present or publish results that are based on it. EPFL makes no warranties of any kind on this software and shall in no event be liable for damages of any kind in connection with the use and exploitation of this technology.

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© 2014 EPFL • • 04.02.2014