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GRASS GIS 6.4.6svn Reference Manual

Geographic Resources Analysis Support System, commonly referred to as GRASS, is a Geographic Information System (GIS) used for geospatial data management and analysis, image processing, graphics/maps production, spatial modeling, and visualization. GRASS is currently used in academic and commercial settings around the world, as well as by many governmental agencies and environmental consulting companies.

This reference manual details the use of modules distributed with Geographic Resources Analysis Support System (GRASS), an open source (GNU GPL'ed), image processing and geographic information system (GIS).

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imagery commands:
i.atcorr Performs atmospheric correction using the 6S algorithm.
i.cca Canonical components analysis (cca) program for image processing.
i.class Generates spectral signatures for an image by allowing the user to outline regions of interest.
i.cluster Generates spectral signatures for land cover types in an image using a clustering algorithm.
i.fft Fast Fourier Transform (FFT) for image processing.
i.fusion.brovey Brovey transform to merge multispectral and high-res panchromatic channels
i.gensig Generates statistics for i.maxlik from raster map.
i.gensigset Generates statistics for i.smap from raster map. Creates, edits, and lists groups and subgroups of imagery data.
i.his.rgb Transforms raster maps from HIS (Hue-Intensity-Saturation) color space to RGB (Red-Green-Blue) color space.
i.ifft Inverse Fast Fourier Transform (IFFT) for image processing.
i.image.mosaic Mosaics up to 4 images and extends colormap; creates map *.mosaic Import of SPOT VGT NDVI file into a raster map
i.landsat.acca Performs Landsat TM/ETM+ Automatic Cloud Cover Assessment (ACCA).
i.landsat.rgb Performs auto-balancing of colors for LANDSAT images.
i.landsat.toar Calculates top-of-atmosphere radiance or reflectance and temperature for Landsat MSS/TM/ETM+/OLI
i.maxlik Classifies the cell spectral reflectances in imagery data.
i.modis.qc Extracts quality control parameters from Modis QC layers.
i.oif Calculates Optimum-Index-Factor table for LANDSAT TM bands 1-5, & 7 Menu driver for the photo imagery programs.
i.pca Principal components analysis (PCA) for image processing. Interactively mark fiducial or reseau points on an image. Creates control points on an image to be ortho-rectified. Interactively select and modify the imagery group camera reference file. Interactively creates or modifies entries in a camera initial exposure station file for imagery group referenced by a sub-block. Orthorectifies an image by using the image to photo coordinate transformation matrix.
i.points Mark ground control points on image to be rectified.
i.rectify Rectifies an image by computing a coordinate transformation for each pixel in the image based on the control points.
i.rgb.his Transforms raster maps from RGB (Red-Green-Blue) color space to HIS (Hue-Intensity-Saturation) color space.
i.smap Performs contextual image classification using sequential maximum a posteriori (SMAP) estimation.
i.spectral Displays spectral response at user specified locations in group or images. Targets an imagery group to a GRASS location and mapset.
i.tasscap Tasseled Cap (Kauth Thomas) transformation for LANDSAT-TM data
i.topo.corr Computes topographic correction of reflectance.
i.vpoints Set registration points for an imagery group from a vector map or keyboard entry.
i.zc Zero-crossing "edge detection" raster function for image processing.

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© 2003-2016 GRASS Development Team, GRASS GIS 6.4.6svn Reference Manual