omni.preprocessing

Image preprocessing functions.

Functions

clahe(img[, clip_limit])	Contrast Limited Adaptive Histogram Equalization
equalize(img[, precision])	Applies histogram equalization to the image.
localized_contrast_enhance(img, mask[, nfrac])	Localized histogram equalization.
normalization(img)	Normalizes an image from 0 to 1
saturate(img[, n])	Similar behavior to MATLAB imadjust.

omni.preprocessing.clahe(img: Nifti1Image, clip_limit: float = 0.02) → Nifti1Image

Contrast Limited Adaptive Histogram Equalization

A simple wrapper around the CLAHE algorithm from skimage.

Parameters:

img: nib.Nifti1Image

input image

Returns:

nib.Nifti1Image

output image

omni.preprocessing.equalize(img: Nifti1Image, precision: int = 4) → Nifti1Image

Applies histogram equalization to the image.

Parameters:

img: nib.Nifti1Image

Image to histogram equalize.

precision: int

Number of decimal places to estimate historgram bins.

Returns:

nib.Nifti1Image

Historgram equalized image.

omni.preprocessing.localized_contrast_enhance(img: Nifti1Image, mask: Nifti1Image, nfrac: float = 0.05) → Nifti1Image

Localized histogram equalization.

Applies histogram equalization to image, but scales it so that the range of values inside the mask are enhanced.

Parameters:

img: nib.Nifti1Image

Image to contrast enhance.

mask: nib.Nifti1Image

Image containing region to constrast enhance.

nfrac: float

Fraction of voxels to use inside mask.

Returns:

nib.Nifti1Image

LCE image.

omni.preprocessing.normalization(img: Nifti1Image) → Nifti1Image

Normalizes an image from 0 to 1

Parameters:

img: nib.Nifti1Image

Image to normalize.

Returns:

nib.Nifti1Image

Normalized image.

omni.preprocessing.saturate(img: Nifti1Image, n: float = 0.01) → Nifti1Image

Similar behavior to MATLAB imadjust.

Saturates bottom/top n of data.

Parameters:

img: nib.Nifti1Image

Image to saturate.

n: float

Percentage (as decimal) of voxels to saturate.

Returns:

nib.Nifti1Image

Saturated image.