• ASCIIIMG: Importing ASCII raster files to MiraMon raster files

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Presentation and options

This application converts raster files from several ASCII formats to MiraMon (IMG format). Supported ASCII formats may have header records (lines). These lines normally refer to some characteristics of the file, such as the number of columns and rows, etc. Depending on the treatment of these header lines, ASCIIIMG has three options:

ASCIIIMG ESRI: This option interprets the header of the ESRI ASCII format to transform the file.

ASCIIIMG NO ENV: In this option neither the scope nor the reference system is indicated. The number of columns, rows and number of lines that contains the ASCII file must be write manually, as well as the number of header lines to skip.

ASCIIIMG ENV: In this option the scope and the reference system is indicated. The number of columns, rows and number of lines that contains the ASCII file must be write manually, as well as the number of header lines to skip.

Thereby, ASCIIIMG supports four main types of ASCII files:

• ESRI ASCII raster format: The ArcGIS format ASCII (normally with .asc extension) is imported.
  
  
• Fixed record: In this case the values of each cell or pixel of the raster always occupy the same number of characters in the file. Consequently the values can even be "pasted" together. Examples:
  Examples:

       -> " 45 73  2 12"
  

  contains, on a fixed record of 3 characters, the values 45, 73, 2 and 12.

       -> "123 45  7255"
  

  contains, on a fixed record of 3 characters, the values 123, 45, 7 and 255.
  
  In this type carriage returns are ignored.
  
  
• Values separated by a delimiter. The delimiter can consist on any number of blanks, tabs or carriage returns.
  Examples:

       -> 45 73 2 12
       -> 45      73 2 12
       -> 45
          73
          2
          12
  

  It is the most frequent case.


• Columns structured values.
  Example:

      V    68    Scrub
      V    84    Conifers
      A    37    Water
      V    72    Scrub
      

Supported output data types are: bit, byte, integer, uinteger, long and real, with RLE compression or without compression.

ASCIIIMG supports carriage returns in DOS/Windows-style (0x0D 0x0A) and in UNIX-style (0x0D).

A flag value (or 'NoData') can be indicated. This value will be used both when logging explicit values (such as those given in some ESRI header files) and when the conversion is out of range.

The application documents a minimal set of metadata, which can be enriched with GeM+ later if desired. Documented metadata are:

data type   : 
file type   : 
columns     : 
rows        : 
min. value  : 
max. value  : 
flag value  : 

ref. system : 
ref. units  : 
min. X      : 
max. X      : 
min. Y      : 
max. Y      : 
resolution  : 

ref. system : plane
ref. units  : pixels
min. X      : 0
max. X      : nfil
min. Y      : 0
max. Y      : ncol
resolution  : 1

file title  : 
unit dist.  : 1.0
pos'n error : unknown
value units : unspecified
value error : unknown
flag def'n  : background
legend cats : 0

The application controls whether the input image is complete or not (truncated). In the last case, if the deficit of cells or pixels is less than a 70%, the application fills the rest of the image with the last read value. This way, the imported image can be visualized or clipped to keep only the valid cells.

Dialog box of the application

Dialog box of ASCIIIMG.