brain_deer.utils.fa_dec¶
FA (Fractional Anisotropy) and direction-encoded color (DEC) utilities for DTI visualization.
Direction-encoded color maps fiber orientation using the principal eigenvector (V1): - Red: left-right (x) - Green: anterior-posterior (y) - Blue: superior-inferior (z)
Standard formula: RGB = abs(V1) * FA (absolute eigenvector components weighted by FA for brightness)
Functions¶
|
Compute direction-encoded color (DEC) FA map. |
Module Contents¶
- brain_deer.utils.fa_dec.compute_fa_dec(fa_path: str, v1_path: str | None = None, fa_image: nibabel.Nifti1Image | None = None) tuple[nibabel.Nifti1Image, bool]¶
Compute direction-encoded color (DEC) FA map.
Uses fa_image if provided (RAS-reoriented); DEC is computed in raw space then reoriented to match. If fa_image is None, loads from fa_path. If v1_path is None, searches for V1 alongside the FA file. Returns (nifti_image, is_dec) where is_dec is True if DEC was computed.