Utilities Developer Guide
MONAI Physio utility classes provide reusable operations for images, transforms, contours, and USD files. They are class-based APIs, not module-level free functions.
Transform Tools
import itk
from monai_physio import ProcessTransforms
tools = ProcessTransforms()
transform = itk.transformread("fixed_to_moving_transform.hdf")
moving = itk.imread("moving.mha")
reference = itk.imread("reference.mha")
warped = tools.transform_image(moving, transform, reference)
For PyVista contours:
import itk
import pyvista as pv
from monai_physio import ProcessTransforms
mesh = pv.read("heart_t0.vtp")
transform = itk.transformread("fixed_to_moving_transform.hdf")
transformed = ProcessTransforms().transform_pvcontour(mesh, transform)
Contour Tools
import itk
from monai_physio import ProcessContours
mask = itk.imread("heart_mask.nrrd")
contour = ProcessContours().extract_contours(mask)
contour.save("heart_surface.vtp")
USD Tools
from monai_physio import ProcessUSD
tools = ProcessUSD()
tools.merge_usd_files(
"combined.usd",
["heart.usd", "lung.usd", "vessels.usd"],
)
USD Anatomy Tools
from pxr import Usd
from monai_physio import ProcessUSDAnatomy
stage = Usd.Stage.Open("anatomy.usd")
painter = ProcessUSDAnatomy(stage)
painter.apply_anatomy_material_to_mesh("/World/Heart", "heart")
stage.Export("anatomy_painted.usd")
Image Tools
ProcessImages contains conversion and small image helpers used internally by
registration and transform utilities. Prefer direct ITK I/O for ordinary
example code:
import itk
image = itk.imread("input.nrrd")
itk.imwrite(image, "output.mha")