GRIDR Release Notes v0.5.0

Release Date: 2026-01-13
Type: Major Feature Release

🎯 What’s New

B-Spline Interpolation

B-Spline interpolation is now available in GRIDR, delivering smoother results than traditional linear interpolation.

Available orders: 3, 5, 7, 9, and 11.

from gridr.core.interp.interpolator import BSpline5Interpolator

# Create a B-Spline interpolator of order 5
interpolator = BSpline5Interpolator(epsilon=1e-4, mask_influence_threshold=0.001)

Important: B-Spline interpolation automatically handles masked/invalid pixels, preventing artifacts from propagating into your results.

Standalone Mode - Simplified Workflow for the Core method

New standalone mode makes grid resampling easier than ever! Just enable it and GRIDR automatically handles all the complex preprocessing steps:

from gridr.core.grid.grid_resampling import array_grid_resampling

result = array_grid_resampling(
    src_array=image,
    grid_x=target_x,
    grid_y=target_y,
    interpolator="cubic",
    standalone=True  # ← Enable standalone mode
)

What standalone mode does for you:

✅ Computes grid metrics automatically
✅ Detects required source regions
✅ Applies padding when needed
✅ Performs B-Spline prefiltering
✅ Handles masked data correctly

No more manual data preprocessing! Perfect for quick prototyping.

Boundary Conditions

Control how pixels are handled at image borders with four new boundary modes:

Mode	Description
`'edge'`	Repeat edge pixels
`'reflect'`	Mirror at boundaries
`'symmetric'`	Symmetric reflection
`'wrap'`	Wrap to opposite edge

Available for both Core and Chain Grid Resampling methods!

result = array_grid_resampling(
    ...,
    boundary_condition='reflect',  # Choose your mode
    standalone=True
)

Eliminates edge artifacts - No more black borders or strange values at image edges!

Grid Coordinates Shifting

The introduction of the grid_shift parameter now enables seamless adaptation to various grid pixel coordinate system conventions, providing greater flexibility and compatibility across different imaging tools.

from gridr.chain.grid_resampling_chain import basic_grid_resampling_chain

chain = basic_grid_resampling_chain(
    ...,
    grid_shift=(0.5, 0.5)  # Shift by half a pixel
)

🛡️ Improved Stability & Safety

Automatic Safety Checks

GRIDR now automatically detects and prevents out-of-bounds errors when working with complex geometric transformations:

Safe handling of non-topology-preserving grids
Automatic detection of valid source regions

Enhanced Numerical Precision

Floating-point precision issues have been resolved, addressing potential problems with:

❌ Nearest-neighbor interpolation selecting wrong pixels
❌ Inconsistent results between the Core and the Chain resampling methods for Nearest-neighbor interpolation.

📚 Breaking Changes

⚠️ Interpolator Creation

What changed: Interpolators must now be created as Python objects before passing to the Rust core resampling functions.

Before (v0.4.x):

array_grid_resampling(..., interpolator='cubic')

Now (v0.5.0):

from gridr.core.interp.interpolator import OptimizedCubicInterpolator, get_interpolator

# Still working for python functions
interp = BilinearInterpolator()
array_grid_resampling(..., interpolator="cubic")

# New interpolator object
interp = OptimizedBicubicInterpolator()
array_grid_resampling(..., interpolator=interp)

# New helper method
interp = get_interpolator("cubic")
array_grid_resampling(..., interpolator=interp)

Why? This enables advanced features like parametrized/stateful interpolators and shared pretabulated coefficients.

📖 Documentation Updates

New Resources

Theoretical Foundations - Mathematical details of grid resampling conventions
Updated Users Guide - Addition of a section to the user guide for new features

Improved Math Rendering

Documentation now uses MathJax 3 for faster, more reliable equation rendering, and includes citation support for academic references.

🔧 Migration Guide

Updating Your Code

Step 1: Consider using standalone mode

# Simplify your code with standalone mode
result = array_grid_resampling(
    src_array=image,
    grid_x=grid_x,
    grid_y=grid_y,
    interpolator=interp,
    standalone=True  # Add this!
)

Step 2: Add boundary conditions if needed

result = array_grid_resampling(
    ...,
    boundary_condition='reflect',  # Prevent edge artifacts
    standalone=True
)

🐛 Bug Fixes

Fixed crashes when resampling with extreme geometric transformations
Fixed nearest-neighbor interpolation precision errors
Added missing Shapely dependency
Improved notebook CSS styling for better readability

📦 Installation

pip install --upgrade gridr

Requirements:

Python ≥ 3.10
PyO3 ≥ 0.27.2

💬 Need Help?

📖 Documentation: https://gridr.readthedocs.io/
🐛 Report Issues: GitHub Issues
💡 Discussions: GitHub Discussions