====== ERMapper Format ======

The [[http://www.erdas.com/products/ERDASERMapper/ERDASERMapper/Details.aspx|ERMapper]] map format is implemented by Dinamica EGO as follows:

  * Maps are represented using two different files: 
     * The header file uses the extension ".ers" and stores the map meta data.
     * The data file does not use an extension and stores the cells from all map layers interlaced by lines. Compression is never used.

   * Due to format limitations, maps whose cells are represented using 1 bit per cell are written using 8 bits per cell, unsigned.
   
   * Blanks in layer names are automatically replaced by "_" (underscore) when reading maps.
   
===== Header Format =====

The ERMapper header written by Dinamica EGO always have the format below:

<code>
DatasetHeader Begin
    Version     = "6.0"
    LastUpdated = %Date%
    DataSetType = ERStorage
    DataType    = Raster
    ByteOrder   = %ByteOrder%
    CoordinateSpace Begin
        Datum          = "%Datum%"
        Projection     = "%Projection%"
        CoordinateType = %CoordinateType%
        Rotation       = 0:0:0.0
    CoordinateSpace End
    RasterInfo Begin
        CellType      = %CellType%
        NullCellValue = %Null%
        CellInfo Begin
            Xdimension = %CellWidth%
            Ydimension = %CellHeight%
        CellInfo End
        NrOfLines        = %Lines%
        NrOfCellsPerLine = %Columns%
        RegistrationCoord Begin
            Eastings  = %RegistrationCoordinateX%
            Northings = %RegistrationCoordinateY%
        RegistrationCoord End
        RegistrationCellX = %RegistrationCellX%
        RegistrationCellY = %RegistrationCellY%
        NrOfBands = %Layers%
        BandId Begin
            Value = "%LayerName1%"
        BandId End
        ...
        BandId Begin
            Value = "%LayerNameN%"
        BandId End
        RegionInfo Begin
            Type       = Class
            RegionName = "%ClassName1%"
            RBGcolour Begin
                Red   = %Red1%
                Green = %Green1%
                Blue  = %Blue1%
            RBGcolour End
            ClassNumber = %Class1%
        RegionInfo End
        ...
        RegionInfo Begin
            Type       = Class
            RegionName = "%ClassNameN%"
            RBGcolour Begin
                Red   = %RedN%
                Green = %GreenN%
                Blue  = %BlueN%
            RBGcolour End
            ClassNumber = %ClassN%
        RegionInfo End
    RasterInfo End
DatasetHeader End
</code>

The text delimited by "%" is replace by the corresponding value in the map instance.