Coregix

Coregix provides pairwise raster coregistration for geospatial imagery.

Coregix coregisters a source raster to a reference raster while preserving geospatial metadata and multi-band outputs. By default, it estimates a translation followed by a rigid transform using mutual-information optimization, then applies the resulting transform to produce a coregistered GeoTIFF.

Current scope:

• pairwise GeoTIFF coregistration CLI and Python API
• edge-proxy registration for cross-sensor structural alignment
• chunked transform application for large source rasters
• optional postprocess trimming of invalid edge artifacts

Install

Conda environment

conda env create -f environment.yml
conda activate coregix

This installs the runtime stack and the package in editable mode.

Editable install into an existing environment

pip install -e .

The installed CLI entrypoint is:

align-image-pair --help

You can also run the module directly:

python -m coregix.cli.align_image_pair --help

Docker

Build the image from the repository root:

docker build -t coregix .

Release images are published to Docker Hub as iosefa/coregix.

Run the CLI with a mounted data directory:

docker run --rm \
  -v "$PWD:/data" \
  iosefa/coregix:latest \
  --moving-image /data/source.tif \
  --fixed-image /data/reference.tif \
  --output-image /data/aligned.tif

If you built the image locally, use coregix instead of iosefa/coregix:latest.

CLI usage

Coregister a source image to a reference image

align-image-pair \
  --moving-image /path/to/source.tif \
  --fixed-image /path/to/reference.tif \
  --output-image /path/to/aligned.tif

By default this:

• registers on edge-proxy images
• writes the result on the source-raster grid
• uses no chunking (--split-factor 0)

Use chunking for large source rasters

--split-factor controls chunked transform application as 2^k total chunks:

• 0: no split
• 1: halves
• 2: quadrants
• 3: octants

Example with quadrants:

align-image-pair \
  --moving-image /path/to/source_large.tif \
  --fixed-image /path/to/reference.tif \
  --output-image /path/to/aligned_large.tif \
  --split-factor 2

Use coarse-to-fine registration for large initial offsets

--solve-resolutions runs multiple registration solves from coarse to fine, then writes the final raster once from the original source image. Use 0 for the reference-raster/native solve resolution.

--solve-resolution is deprecated and remains available for single-pass compatibility. Prefer --solve-resolutions, even for one solve.

align-image-pair \
  --moving-image /path/to/source_large.tif \
  --fixed-image /path/to/reference.tif \
  --output-image /path/to/aligned_large.tif \
  --split-factor 2 \
  --solve-resolutions 8,4,0.5

Remove invalid edge artifacts after alignment

--trim-edge-invalid runs a raster-space cleanup pass after alignment and sets edge artifacts to nodata.

Example:

align-image-pair \
  --moving-image /path/to/source_large.tif \
  --fixed-image /path/to/reference.tif \
  --output-image /path/to/aligned_large_edgefixed.tif \
  --split-factor 2 \
  --trim-edge-invalid \
  --edge-trim-depth 8 \
  --edge-trim-invalid-below -3000

The edge-trim thresholds are dataset-specific. --edge-trim-invalid-below is useful when interpolation artifacts are not equal to the dataset nodata value.

Python usage

Basic alignment

from coregix import align_image_pair

result = align_image_pair(
    moving_image_path="/path/to/source.tif",
    fixed_image_path="/path/to/reference.tif",
    output_image_path="/path/to/aligned.tif",
)

print(result.output_image_path)

Large raster with chunking and edge cleanup

from coregix import align_image_pair

result = align_image_pair(
    moving_image_path="/path/to/source_large.tif",
    fixed_image_path="/path/to/reference.tif",
    output_image_path="/path/to/aligned_large_edgefixed.tif",
    split_factor=2,
    trim_edge_invalid=True,
    edge_trim_depth=8,
    edge_trim_invalid_below=-3000,
)

print(result.output_image_path)

Notes

• split_factor changes only transform application, not the registration model.
• split_factor=2 is the direct replacement for the previous quadrant-based large-raster path.
• If needed, you can select separate registration bands with moving_band_index and fixed_band_index in Python or --moving-band-index and --fixed-band-index in the CLI.