10.133. Resample Data (Image Geometry)

Group (Subgroup)

Sampling (Resample)

Description

This Filter changes the cell resolution of an Image Geometry by overlaying a new regular grid on the existing data and copying the closest-cell value from the old grid to each new cell. No interpolation is performed.

The overall bounds of the volume do not change – only the spacing and the number of cells. To scale the physical extent of a geometry, apply a scaling transformation with Apply Transformation To Geometry instead.

Fig. 1: Resampling overlays a new grid of a different spacing on the same physical volume; doubling the spacing along an axis halves the cell count there. Each new cell takes the value of the nearest source cell — no interpolation is performed.

Resampling Mode

The Resampling Mode parameter provides three ways to specify the new grid:

Spacing [0]: Set the new spacing directly (in physical units; same as the input geometry’s spacing). The cell count adjusts accordingly. Use small spacings cautiously – they can produce very large cell counts.
Scaling [1]: Scale spacing by a percentage per axis. A scaling factor of 30% reduces cell count to roughly 30% of the original (and increases spacing by ~3.33x).
Exact Dimensions [2]: Set the exact new cell counts per axis (integer). Spacing is computed automatically to span the original bounds.

Spacing Examples

Image with cell dimensions (524, 390, 164) and spacing (1, 1, 1) (units in microns/voxel).

New spacing (2, 2, 2) → cell dimensions (262, 195, 82), spacing (2, 2, 2) microns/voxel.
New spacing (0.25, 0.7, 2.3) → cell dimensions (2096, 557, 71), spacing (0.25, 0.7, 2.3).

Scaling Examples

Same starting image.

Scaling (30%, 30%, 30%) → cell dimensions (157, 117, 49), spacing (3.333, 3.333, 3.333).
Scaling (120.4%, 50.74%, 68.12%) → cell dimensions (630, 197, 111), spacing (0.831, 1.971, 1.468).

Exact Dimensions Examples

Same starting image.

Exact dimensions (100, 100, 100) → cell dimensions (100, 100, 100), spacing (5.24, 3.9, 1.64).
Exact dimensions (100, 500, 20) → cell dimensions (100, 500, 20), spacing (5.24, 0.78, 8.2).

Resampling Algorithm

A new regular grid is overlaid on the old one. For each new cell, the filter finds the old cell whose center is closest and copies that old cell’s attributes (Feature Ids, phases, orientations, etc.) into the new cell. There is no interpolation – this is the right behavior for label data (Feature Ids), but it does mean that small features can disappear during downsampling.

Renumber Features

When downsampling produces a result in which some Features no longer have any cells, those Features become invalid. Enable Renumber Features to detect this case, resize the Cell Feature Attribute Matrix to drop the empty features, and renumber the remaining features so that Feature IDs remain contiguous starting at 1.

WARNING: NeighborList Removal

When Renumber Features is enabled and the Cell Feature Attribute Matrix contains any NeighborList arrays, those arrays are removed because they refer to the old (pre-renumber) Feature IDs. Re-run Compute Feature Neighbors afterward to rebuild them.

Required Input Sources

Input Image Geometry – the geometry to be resampled. Typically produced by Create Image Geometry, ITK Import Image Stack, or an EBSD reader.

Input Parameter(s)

Parameter Name	Parameter Type	Parameter Notes	Description
Resampling Mode	Choices		Mode can be [0] Spacing, [1] Scaling as Percent, [2] Exact Dimensions as voxels
New Spacing	Vector of Float32 Values	Order=X,Y,Z	The new spacing values (dx, dy, dz). Larger spacing will cause less voxels, smaller spacing will cause more voxels.
Scale Factor (percentages)	Vector of Float32 Values	Order=X%,Y%,Z%	The scale factor values (dx, dy, dz) to resample the geometry, in percentages. Larger percentages will cause more voxels, smaller percentages will cause less voxels. A percentage of 100 in any dimension will not resample the geometry in that dimension. Percentages must be larger than 0.
Exact Dimensions (pixels)	Vector of UInt64 Values	Order=X,Y,Z	The exact dimension size values (dx, dy, dz) to resample the geometry, in pixels.
Perform In Place	Bool		Removes the original Image Geometry after filter is completed

Input Image Geometry

Parameter Name	Parameter Type	Parameter Notes	Description
Selected Image Geometry	Geometry Selection	Image	The target geometry to resample

Optional Renumber Features

Parameter Name	Parameter Type	Parameter Notes	Description
Renumber Features	Bool		Specifies if the feature IDs should be renumbered
Cell Feature Ids	Array Selection	Allowed Types: int32 Comp. Shape: 1	Specifies to which feature each cell belongs.
Feature Attribute Matrix	AttributeMatrixSelection		DataPath to the feature Attribute Matrix

Output Image Geometry

Parameter Name	Parameter Type	Parameter Notes	Description
Created Image Geometry	DataGroupCreation		The location of the resampled geometry

Example Pipelines

SimplnxCore/ResamplePorosityImage

License & Copyright

Please see the description file distributed with this Plugin

DREAM3D-NX Help

If you need help, need to file a bug report or want to request a new feature, please head over to the DREAM3DNX-Issues GitHub site where the community of DREAM3D-NX users can help answer your questions.