TomoImageStitcher

A GPU-accelerated, sub-pixel accurate 3D volumetric stitcher for tomographic and large-volume microscopy datasets. TomoImageStitcher registers overlapping 3D sub-volumes acquired on a translation (and optionally rotation) stage and produces a single seamless volume with mask-aware blending and optional intensity equalisation.

Originally developed for stitching local X-ray tomography volumes for the Experiment at the DanMAX beamline, Sweden.

For a detailed step-by-step walkthrough of every pipeline stage with synthetic data, see notebooks/02_full_pipeline.ipynb. For the mathematical details of the registration, see [PUBLICATION].

What is it

TomoImageStitcher stitches together a set of overlapping 3D sub-volumes (typically reconstructed tomography volumes) into one seamless volume. Each stage is a Python call on the Stitcher object, so you can inspect and re-run any stage on its own.

The pipeline runs in six stages:

The full per-stage walk-through with the code for every step lives in the detailed notebook linked above. The math behind the registration and blending lives in [PUBLICATION].

Where you can use it

• Stitching 3D X-ray tomography reconstructions from a multi-tile translation scan.
• Stitching raw projection volumes (radiographs) before reconstruction.
• Stitching 3D microscopy datasets (light-sheet, confocal) where individual tiles are too large to fit into memory.
• Multi-scan stitching where you have several scans with overlapping lateral extent.
• Stitching on a rotation stage (helical or tomographic) — see notebooks/03_stitching_with_rotation.ipynb.

Install

TomoImageStitcher is on PyPI. A CUDA-capable GPU with the matching CuPy wheel is required for the GPU stages; everything else is plain Python.

# 1. (Recommended) a clean environment
python -m venv .venv && source .venv/bin/activate

# 2. Install with the notebook extras
pip install -U pip
pip install "tomo-image-stitcher[notebook,danmax]"

# 3. Install CuPy matching your CUDA version (CUDA 12.x shown)
pip install cupy-cuda12x

If you cannot install git, or you are behind a proxy that blocks it:

pip install https://github.com/indrajeettambe/TomoImageStitcher/archive/main.zip

For full instructions (drivers, conda env, troubleshooting) see docs/installation.md.

Quick start

A minimal end-to-end example on synthetic data. The full version with explanations and intermediate visualisations is in notebooks/02_full_pipeline.ipynb.

import numpy as np
from tomo_image_stitcher import Stitcher

# 1. List of .h5 files and their motor positions in millimetres
file_paths    = ["scan_001.h5", "scan_002.h5", "scan_003.h5"]
motor_coords  = np.array([[ 0.0,  0.0,  0.0],
                          [ 0.8,  0.0,  0.0],
                          [ 1.6,  0.0,  0.0]])
mm_per_voxel  = 0.0022                       # 2.2 µm voxels

# 2. Initialise the stitcher
st = Stitcher(file_paths, motor_coords, mm_per_voxel,
              x_y_z_correspondance=(-1, 3, 2))

# 3. Run the six stages
st.get_layers_in_z(tolerance_mm=4)           # (1) Organise
st.get_padding()
st.get_intersections(check=True)
st.compute_shift_in_layers(downscale=4, downscale_stages=4,   # (2) Registration
                           downscale_LC=True, mask=True, mask_radius=300)
st.get_displacement_pyramid(check=False)
st.accumulate_displacement(exclude_NCC=50)   # (3) Accumulate
st.compose_final_displacements()
st.stitch_volumes_blend_equalize(...)        # (4) + (5) Equalise + Blend
st.stitch_layers(path_save="output/")        # (6) Save

# 4. Read the stitched volume
import h5py
with h5py.File("output/Stitched_layers/Layer_0.h5", "r") as f:
    volume = f["stitched_data/stitched_image"][:]

Documentation

The mathematical details of the registration (ZNCC, IC-GN Lucas–Kanade, mask weighting) and blending (distance-map weighting) are described in [PUBLICATION].

Project layout

TomoImageStitcher/
├── src/tomo_image_stitcher/    Package source (Stitcher, RegistrationKIT, …)
├── notebooks/                  Jupyter tutorials (start with 02_full_pipeline)
├── examples/                   Standalone Python scripts
├── tests/                      pytest test-suite
├── docs/                       Architecture, API, troubleshooting
├── pyproject.toml              Build & dependency metadata
├── LICENSE                     MIT
└── CITATION.cff                Software citation

Citation

If you use TomoImageStitcher in your research, please cite it using the metadata in CITATION.cff. A publication describing the algorithm is in preparation and will be linked here when available ([PUBLICATION]).

License

MIT — see LICENSE.

Contributors

TomoImageStitcher was originally developed at the DanMAX beamline (MAX IV Laboratory, Sweden). See the git log for the full list of contributors.