Converting Geotiff Image Files
Some Geotiff Image files are in the 24 bit color format. OziExplorer can read 24 bit color TIFF files but must load them fully into RAM instead of paging them from disk as it does with 8 bit color TIFF mages. For large images this requires a lot of RAM.
If you convert these files to 8 bit color the Geotiff georeference information is lost.
This document describes a technique to save the georeference information and to then put it back into the file.
You need
Software to convert the Geotiff image from 24 bit to 8 bit color. Paint Shop Pro (www.jasc.com) works well.
The Tiff Utilities available from the Utilities section of the OziExplorer web site (www.oziexplorer.com).
Steps
These instructions assume the geotiff file you are converting is called mytiff.tif and is located in a folder called c:\images, replace this with the real name of the tif file and path.
Step 1
Open a DOS window.
Step 2
Use the listgeo.exe program to save the georeference information from the geotiff file into a file called mytiff.met, actually this file can have any name.
listgeo c:\images\mytiff.tif >c:\images\mytiff.met
Step 3
Convert the image to 8 bit color using Paint Shop Pro, the image is saved to mytiff1.tif, the compression method must be packbits and this is set up in the options buttion on the save dialog.
Step 4
Use the geotifcp.exe program to put the georeference information back into the file.
geotifcp -g c:\images\mytiff.met c:\images\mytiff1.tif c:\images\mytiff2.tif
The file can now be imported and opened in OziExplorer.