Hemisfer

Hemisfer is a software designed to estimate the leaf area index (LAI) and the light regime from hemispherical photographs.

Originally, Hemisfer was developed because we wanted to compare different mathematical methods to calculate LAI. We compared results of some free or commercial software packages and could not understand some diverging results. We therefore programmed 4 different methods in a single software. Trying to optimise the calculations, we found a further method to solve the problem. Improving the software step by step, we finally obtained a software with several interesting technical features, some of them available for the first time worldwide.

Since the development of this software was carried out within a public research institute, we have an interest to share it and to make our results known.

In its free downloadable version, Hemisfer is fully functional. The only limitation is that it cannot analyse hemispherical pictures exceeding 1000 pixels in diameter. This is sufficient for all sorts of tests and exercises and the results will be quite accurate in most cases. Actually, LAI estimates are less affected by the resolution of the picture than by many other factors where Hemisfer offers valuable solutions and advices (through its integrated help).

The limitation in size is removed when the software is registered. For a strictly non-profit use, the registration of Hemisfer is very affordable (only 80 Swiss francs). For commercially-oriented uses, the price is still very competitive (500 Swiss francs). Registration and payment can be done easily and online. Registered users are entitled to a technical support (see our terms of use). A page of frequently asked questions (FAQ) is also available.

To test Hemisfer, we also developped a software, called Canopix, to produce artificial canopy pictures. It produces random pictures according to three user-set parameters: LAI, mean leaf angle and ground slope. Canopix can be dowloaded as freeware.