====== Image World File ======

A world file is a plain text file used by geographic information systems to georeference raster map images.
Small-scale rectangular raster image maps can have an associated world file for GIS map software which describes the location, scale and rotation of the map. These world files are six-line files with decimal numbers on each line.

<note important>World files do not specify a coordinate system. \\ This information is generally stored in another companion file, the [[2210:technology:supported_formats:other:ord|]] File (ORD)</note>

==== Structure ====

An world file is a plain text file used by Orbit to georeference an image file. 
The world file is always associated with an OMI file : it describes the location, scale and rotation of the map. These world files are six-line files with decimal numbers on each line.

More information can be found on: https://en.wikipedia.org/wiki/World_file.

==== Create ====

Create and edit these files using a text editor. Take care of spelling and file syntax. \\

=== Parameters ===

  * Line 1: pixel size in the x-direction in map units/pixel
  * Line 2: rotation about y-axis
  * Line 3: rotation about x-axis
  * Line 4: pixel size in the y-direction in map units
  * Line 5: x-coordinate of the center of the upper left pixel
  * Line 6: y-coordinate of the center of the upper left pixel

\\
==== Examples of Associated World Files ====

^  Format  ^  Image Data File  ^  Image World File  ^ 
| [[2210:technology:supported_formats:image:omi|]] |  .omi  |  .oiw  |
| [[http://en.wikipedia.org/wiki/ECW_(file_format)|ECW]] |  .ecw  |  -  | 
| [[http://en.wikipedia.org/wiki/BMP_file_format|Bitmap]] |  .bmp  |  .bpw  |
| [[http://en.wikipedia.org/wiki/Gif|Graphics Interchange Format]] |  .gif  |  .gfw  |
| [[http://en.wikipedia.org/wiki/Jpeg|JPEG]] |  .jpg  |  .jgw  | 
| [[http://en.wikipedia.org/wiki/Portable_Network_Graphics|Portable Network Graphics]] |  .png  |  .pgw  |
| [[http://en.wikipedia.org/wiki/MrSID|Mister Sid]] |  .sid  |  .sdw  |
| [[http://en.wikipedia.org/wiki/Tagged_Image_File_Format|Tagged Image File Format]] |  .tif(f)  |  .tfw  |

[[http://en.wikipedia.org/wiki/World_file]]