PyGeometry

class multimodars.PyGeometry(frames, label)

Bases: object

Python representation of a full intravascular imaging geometry (sequence of frames).

frames

Ordered list of imaging frames constituting the geometry.

Type:: list of PyFrame

label

Human-readable label for this geometry.

Type:: str

Examples

>>> geom = PyGeometry(
...     frames=[frame1, frame2, ...],
...     label="Pat00_diastole"
... )

center_to_contour(contour_type)

Center the entire geometry on a specific contour type.

Parameters:: contour_type (PyContourType) – Contour type to center on (e.g. PyContourType.Lumen).
Returns:: New geometry centered on the specified contour type.
Return type:: PyGeometry

downsample(n_points)

Return a new geometry with n_points per ContourType.

Parameters:: n_points (int) – Number of points remaining per Contour.
Returns:: New downsampled geometry.
Return type:: PyGeometry

Examples

>>> new_geom = geometry.downsample(100)

get_contours(contour_type): Get contours by type string

get_contours_by_type(contour_type): Get all contours of a specific type

get_frame_at_index(index)

Return the frame at position index.

Parameters:: index (int) – Zero-based index of the frame to retrieve.
Returns:: Frame at the given index.
Return type:: PyFrame
Raises:: IndexError – If index is out of range.

Examples

>>> frame = geometry.get_frame_at_index(0)

get_frame_at_z(z)

Return the frame whose centroid z-coordinate is closest to z.

Parameters:: z (float) – Target z position in the same units as the geometry.
Returns:: Frame with centroid z nearest to z.
Return type:: PyFrame
Raises:: ValueError – If the geometry contains no frames.

Examples

>>> frame = geometry.get_frame_at_z(34.8)

get_lumen_contours(): Get lumen contours (convenience method)

get_summary()

Get a compact summary of lumen properties for this geometry.

When all contours have an elliptic ratio below 1.3 the vessel is treated as elliptic and a lenient threshold of 70 % of the maximum area is used to identify stenotic segments; otherwise a stricter 50 % threshold is applied.

Returns:

mla (float) – Minimal lumen area in the units of the input data (e.g. mm²).
max_stenosis (float) – 1 - (mla / max_area).
stenosis_length_mm (float) – Length in mm of the longest contiguous region where the contour area falls below the threshold.

replace_frame(index, frame)

Return a new geometry with the frame at index replaced by frame.

Parameters:

index (int) – Zero-based index of the frame to replace.
frame (PyFrame) – Replacement frame.

Returns:

New geometry with the specified frame replaced.

Return type:

PyGeometry

Raises:

IndexError – If index is out of range.

Examples

>>> new_geom = geometry.replace_frame(5, other_frame)

rotate(angle_deg)

Rotate the entire geometry around its centroid by an angle in degrees.

All frames (lumen, extras) are rotated around the same centroid.

Returns:: New geometry rotated around its centroid.
Return type:: PyGeometry

Examples

>>> geometry = geometry.rotate(20)

smooth_frames()

Apply smoothing to all frames using a three-point moving average.

Returns:: New geometry with smoothed frames.
Return type:: PyGeometry

Examples

>>> geom.smooth_frames()

sort_frame_points()

Re-index all frame contour points so the point with the highest Z-value in frame 0’s lumen gets point_index = 0. The same index offset is applied to every contour in every frame. Physical point positions are unchanged — only the point_index fields are reassigned.

Returns:: New geometry with re-indexed frames.
Return type:: PyGeometry

translate(dx, dy, dz)

Translate all frames in the geometry by (dx, dy, dz).

Parameters:

dx (float) – Translation in the x-direction.
dy (float) – Translation in the y-direction.
dz (float) – Translation in the z-direction.

Returns:

New geometry with all frames translated.

Return type:

PyGeometry