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How To: Change the default compression format for output TIFF files

Summary

Instructions provided describe how to modify the default compression for TIFF raster formats.

Procedure

Default compression methods are set using Preference Definition Files (PDF) that are stored in ..\Program Files\Common Files\ESRI\Raster\defaults for ArcGIS 9.0. The following file can be modified for compression: tiff.pdf.

Note:
While the extension is *.pdf it is not in Adobe's Portable Document Format. Adobe Acrobat is not able to open this document type. Use Microsoft Wordpad or another ASCII text editor.

To change TIFF compression open tiff.pdf in an editor. There are four sections in this file regarding compression. They are headed by: compression_1bit, compression, compression_other and compression_jpeg. For the first three the default compression is 'None', meaning no compression is applied. A list of the available compression methods follows. For example, the entry for compression is:

compression( "8-bit Image Compression" ): "None"
"Compression used for newly created images > 1-bit and <= 8-bit"
enums
{
"None" "None"
"LZW" "LZW"
/*
"JPEG" "JPEG"
*/
"PackBits" "PackBits"
};


The available compression methods are 'None', 'LZW' and 'PackBits'. JPEG is disabled at this time. To change the compression method simply replace the text at the header with one of the selected options. For example, change 'None' to 'Packbits':

compression( "8-bit Image Compression" ): "PackBits"
"Compression used for newly created images > 1-bit and <= 8-bit"
enums
{
"None" "None"
"LZW" "LZW"
/*
"JPEG" "JPEG"
*/
"PackBits" "PackBits"
};

When editing the tiff.pdf file there are a few things to keep in mind. Before editing, make a backup of this file. Any formatting mistakes could cause an error during raster processing. Keeping a backup handy ensures the ability to restore to the original setup of each file. If edits are made, do not forget to save those edits. For the edits to be in effect, shut down and restart ArcMap, ArcCatalog, ArcScene or ArcGlobe.