Automating Image Compression with GeoExpress Command Line Utilities

Getting Started with GeoExpress Command Line Utilities: Essential CommandsGeoExpress is a powerful set of tools for compression, conversion, and handling of large geospatial raster imagery. Its command line utilities let you automate batch processing, integrate with scripts and workflows, and operate on servers without a GUI. This guide covers the essential commands, typical workflows, practical tips, and examples to help you start using GeoExpress from the command line effectively.

What GeoExpress command line utilities do

GeoExpress command line utilities provide:

• Efficient compression of large raster datasets into compact, fast-to-read formats.
• Format conversion between common raster types (GeoTIFF, JPEG2000, MrSID, ECW where supported).
• Image tiling, pyramiding, and overview creation to optimize display and delivery.
• Metadata management and reprojection support.
• Batch processing capabilities for handling many files in scripted workflows.

Installation & environment setup

1. Obtain GeoExpress: GeoExpress is provided by LizardTech (or its successor/maintainer). Ensure you have a licensed copy or trial that includes the command line utilities.
2. Platform support: GeoExpress CLI typically runs on Windows and Linux. Confirm which binaries you received.
3. PATH and permissions: Add the installation directory containing CLI executables (for example, gdalsrsinfo, geocompress, or lizardtech-specific binaries) to your PATH, or call them with absolute paths. Ensure you have execute permissions on Linux (chmod +x).
4. Licensing: Some functionalities require a valid license. Ensure license files or license server settings are accessible to the CLI tools.

Common utilities (names may vary by version)

Note: binary names vary by release. Typical utilities include:

• geocompress (creates compressed packages)
• geodecompress (extracts or converts back to standard formats)
• geooverview (builds image overviews/pyramids)
• geometadata (view/edit metadata)
• geoproject (reprojects datasets)

Check the included README or run the tool with –help for exact names and options.

Essential commands and examples

Below are typical commands and patterns you’ll use frequently. Adjust paths, filenames, options, and formats to your environment.

1. Compressing a single GeoTIFF to a MrSID/JPEG2000 package

   geocompress -i input.tif -o output.sid -format mrsid -quality 20 

   Explanation: -i input file, -o output file, -format selects container, -quality sets compression level (0–100).

2. Batch compress multiple files

   for f in /data/*.tif; do geocompress -i "$f" -o "/out/$(basename "${f%.*}").sid" -format mrsid -quality 25 done 

3. Creating overviews (pyramids) for faster display

   geooverview -i input.sid -levels 2,4,8,16 -method nearest 

4. Reprojecting while compressing

   geoproject -i input.tif -o reprojected.tif -s_srs EPSG:4326 -t_srs EPSG:3857 geocompress -i reprojected.tif -o output.sid -format mrsid -quality 30 

5. Converting back to GeoTIFF

   geodecompress -i input.sid -o output.tif -format geotiff 

6. Inspecting metadata

   geometadata -i input.sid -print 

7. Specifying tile size and block size for optimal performance

   geocompress -i input.tif -o output.sid -tile 512 -block 512 -quality 30 

8. Preserving nodata values and masks

   geocompress -i input.tif -o output.sid -nodata 0 -preserve-mask yes 

Workflow examples

Automated nightly batch compress

#!/bin/bash INPUT_DIR=/data/new OUTPUT_DIR=/data/compressed LOG=/var/log/geocompress.log for f in "$INPUT_DIR"/*.tif; do   base=$(basename "$f" .tif)   geocompress -i "$f" -o "$OUTPUT_DIR/${base}.sid" -format mrsid -quality 25 >> "$LOG" 2>&1 done 

On-the-fly reprojection and compression for web tiles

geoproject -i large.tif -o temp.tif -t_srs EPSG:3857 geocompress -i temp.tif -o large_3857.sid -tile 256 -quality 30 rm temp.tif 

Performance tips

• Choose tile sizes that match your delivery (e.g., 256 or 512 for web).
• Higher quality = less compression. Test to find acceptable trade-off.
• Use multiple threads or parallelize batch jobs where supported.
• Create overviews to improve display speed.
• Strip unnecessary metadata if package size is critical.

Troubleshooting

• “Unknown format” — check tool version; some formats require extra modules or licenses.
• Slow compression — try larger blocks, fewer threads, or higher I/O throughput.
• Projection errors — confirm source CRS and axis order; use EPSG codes when possible.
• Permission denied — check execute permissions and license accessibility.

Where to find help

• Run any utility with –help or -h for options.
• Consult the product documentation supplied with your GeoExpress installation.
• Contact vendor support for licensing or format-specific issues.

This should give you a solid start with GeoExpress command line utilities: how to compress, convert, reproject, and automate processing of large raster imagery. If you want, tell me your OS and a sample input file name and I’ll give tailor-made commands for your environment.