Future COG Optimization #1
Description
Plan: COG optimization experiments (tiling, compression, overviews)
Motivation
COGs are currently generated using terra::writeRaster(filetype = "COG") with mostly default GDAL settings which may not be optimal for tile extraction or data storage.
Plan: run controlled optimization experiments.
Scope
This issue proposes a structured optimization phase to evaluate:
- Runtime
- Output file size
- Practical usability
Experimental design
1. Select test rasters
Choose 1-2 representative rasters:
- Domain score level (values 0-100)
- One other (values 0-50)
2. Parameter grid
Test combinations of:
Compression:
- LZW
- DEFLATE
- NONE
Blocksize:
- 256
- 512
- 1024
Overview resampling:
- AVERAGE
- NEAREST
Threads fixed (e.g. NUM_THREADS=50).
3. Measurement
For each run, record:
- input filename
- parameters
- wall-clock runtime
- output file size
- GDAL/terra version
Write results to a CSV for comparison.
4. Evaluation
Select defaults based on:
- Reasonable runtime for large rasters
- Acceptable file size
- Simplicity and maintainability
Deliverables
- Benchmark results CSV
- Short written summary
- Updated COG generation defaults
Notes
This optimization should occur after correctness is established and before final publication.