Monday, January 2, 2012

Google Gadget for creating ESRI World Files



Note: A WebApp version of this Google Gadget will be up in a short while to replace this gadget.

The ESRI World file is a text file used to georeference a corresponding image file. A detailed description of the format can be found in this Wikipedia page http://en.wikipedia.org/wiki/World_file.

Recently I had to create ESRI World files for hundreds of aerial photographs, each having different origin, resolution and orientation. As a result of that exercise, I learnt enough about the World File format to create this Google Gadget.

This gadget can help to create the world files given the following input parameters:
  1. X coordinate of the upper left pixel in ground units,
  2. Y coordinate of the upper left pixel in ground units,
  3. Size of the pixel in the X-axis direction in ground units,
  4. Size of the pixel in the Y-axis direction in ground units,
  5. Rotation angle in degrees of the image from North (clockwise is positive) 
Just fill in the required input, click the button and copy and paste the results into a world file, which must be named according to the type of image file. For example, the World file should have the file extension of .tfw for associating with TIFF images.




1 comment:

Anonymous said...

the easiest way to get some eyes on your mashup is by creating a Google Gadget in GME and submitting it to the iGoogle Directory.