ischtz/gridfix: Initial release

This is the first release of GridFix after acceptance of the corresponding manuscript (see https://www.frontiersin.org/articles/10.3389/fnhum.2017.00491/abstract).

Supported features:

• Image parcellations based on regular grid
• Explicit modeling of Central Viewer Bias (euclidean distance, Gaussian map, taxicab/manhattan distance)
• Low-level image features: luminance, luminance contrast, edges
• Feature values from saliency maps (mean, peak, ...)
• Generation of predictor files and exemplary R source code for GLMM analysis

Please refer to the documentation for usage examples and references: https://ischtz.github.io/gridfix/