Index
Raster Files A-Z

Raster Documentation Files

remember, a raster in IDRISI carries no information about 'itself' - we need to store that metadata separately. This is done by so-called raster documentation files (*.DOC). All images must have their corresponding DOC-files. These are ASCII files made up by a sequence of lines, each representing metadata. To ease handling, IDRISI comes with a tool called DOCUMENT:

You see a lot of fields which can be divided into obligate and facultative ones.

obligate facultative notes
Titel X purely descriptiv, use it!
Columns / Rows X determines raster structure
Data type X type of values
File type X how is the file stored
Minimum / Maximum value X automatic checking of limits possible
Pos'n error X x,y-position error assessment as RMS error
Resolution X resolution of each cell; automatic calculation: MaxX - MinX / columns; does not always mean the 'true' spatial resolution
Value error X attribute value error, proportional or RMS, used in the calculation of the module PCLASS
Value units X m, classes, kg*ha-1*a-1 or any other unit
Reference system X projectioninformation
Reference units X m, ft, km, mi, deg, rad
Minimum / Maximum X/Y coordinates X image extents
Unit distance X a scaling factor, usually 1.0; eg. 2.0 and reference units meters would mean: a distance of 1 unit represents 2 meters in real
Flag value X a value in your raster with special meaning (background value, nodata, ...); analytically used by SURFACE
Flag definition X description of above values meaning
Legend categories X text for legend
Completness, Consitency, Comments and Lineage X descriptive, use it if you have information

As indicated, several fields are purely descriptive. Nevertheless it is highly recommended to provide any additional information about the data to help assure higher accuracy.
Index
Raster Files A-Z
last modified: | Comments to Eric J. LORUP idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis idrisi resource center idrisi gis idrisi gis