New GUI Features and Performance Improvements in Spectral Python (SPy) 0.13

The SPy imshow wrapper around matplotlib's imshow function provides numerous new features, including:

• Interactive image class labeling using keyboard & mouse

• Zoom windows

• Class overlays with adjustable transparency

• Dynamic view of changing pixel classes when modified in an ND Window.

Data/Statistic cacheing and more efficient use of numpy provides significant performance improvement in mutiple algorithms (GMLC 14x, Mahalanobis classifier 8x, kmeans 3x). Functions rx and matched_filter are significantly faster, particularly when using common global covariance.

The new cov_avg function computes covariance averaged over a set of classes (useful when samples are limited or global covariance is desired). Christian Mielke provided code for the msam function, which computes the Modified SAM score (by Oshigami et al).