IdrMM: Import and export between Idrisi and MiraMon raster formats

This module transforms raster files between MiraMon and Idrisi-32.

The types of transformations that can be carried out are:

• Export of a band of any MiraMon IMG format to Idrisi-32 RST format.
• Import of Idrisi-32 in RST monoband format to MiraMon IMG.
• Export of MiraMon georeferenced JPEGs (J.rel) to a three-RGB band RST file of Idrisi-32.

Both files, IMG and RST, are binary, but MiraMon is not only compatible with Idrisi-32 types. Idrisi-32 can run byte, integer and real types, while MiraMon also runs bit and long types and the corresponding RLE (byte-RLE, integer-RLE...) compressions. As Idrisi-32 cannot run long type, it is possible to decide that the data of the transformed Idrisi-32 file are integer or real by means of an optional parameter. When exporting a MiraMon long-type raster to an integer-type Idrisi-32 file, it is necessary to use the /LONG_SHORT optional parameter and when exporting to a real-type Idrisi-32 parameter it is necessary to select the /LONG_REAL optional parameter. If no optional parameter is selected, the default parameter applied by the module is /LONG_REAL.

When carrying out a transformation from MiraMon to Idrisi-32 with the /LONG_SHORT optional parameter, the application saturates the origin raster values greater than 32767 or less than -32768. The saturation is performed by following the following protocol:

• If the raster contains NODATA values greater than 32766 or less than -32767, the application will set the NODATA value at 32767 for the first case and at -32768 for the second. The remaining values of the origin raster that are greater than 32766 or less than -32767 are assigned to 32766 or -32767 respectively.
• If the origin raster does not contain NODATA values, values greater than 32766 or less than -32767 are assigned to 32767 or -32768 respectively.

It should be noted that this module does not carry out file exports with bit-type data files. In order to do this, it is necessary to transform the data into byte-type using the IMGIMG application and then export to RST. It does not import Idrisi-32 24-bit RST files (three-band compositions) to MiraMon format. In order to do this it is advisable to use a TIFF format (georeferenced as GeoTIFF) as an intermediary and then use the TIFIMG module to obtain the corresponding 24-bit IMG.

Regarding the Idrisi-16 raster files, it should be noted that they have the same format as the MiraMon files. Consequently, all the Idrisi-16 RST raster files which are binary and not compressed can be read directly by MiraMon by means of the "File | Open raster" option. However, there are a number of special situations, which are described below:

From Idrisi-16 to MiraMon:

• If the file is ASCII or compressed ("packed"), it is necessary to convert it to binary non-compressed using the Idrisi-16 CONVERT application (for ASCII it is also possible to use, from MiraMon, "File | Import | ASCII->IMG").
• If one wishes to enlarge the metadata model of the Idrisi-16 DOC file, this should be carried out using GeM+, with the possibility of maintaining both formats (DOC and REL).

From MiraMon to Idrisi-16:

• If the MiraMon raster file is byte and RLE, it is necessary to check that it is not extra-compressed and that it is not indexed (IMGIMG) as well as changing the documentation that appears in the DOC. This is because MiraMon specifies that the data are compressed (RLE) in the same data-type field (e.g. byte-RLE) and Idrisi-16 writes the RLE in another field.
• If the MiraMon raster file contains metadata in REL format, it is necessary to use the Universal Geospatial Metadata Manager (GeM+) to transform them into DOC format.
• If the MiraMon raster file is of long or long-RLE type, it is necessary to take into account the information relating to the transformations between MiraMon and Idrisi-32.
• If the MiraMon raster file is of short or long type with categories (with values greater than 255), it cannot be transformed into Idrisi-16.