Fragstats

FRAGSTATS is a computer software program designed to compute a wide variety of landscape metrics for categorical map patterns.  It interfaces with ArcGIS and supports  and a variety of sampling methods for analyzing sub-landscapes.  It accepts raster images in a variety of formats, including ASCII grid, 8-, 16- and 32-bit integer grids, ESRI grid (or raster), GeoTIFF grid, VTP binary terrain format grid, ESRI header labelled grid, ERDAS Imagine grid, PCRaster grid, and SAGA GIS binary format grid. Support for the latter six image formats is via the GDAL library.

Here is the FragStats official website.