ants.math.image_similarity

image_similarity(fixed_image, moving_image, metric_type='MeanSquares', fixed_mask=None, moving_mask=None, sampling_strategy='regular', sampling_percentage=1.0)[source]

Measure similarity between two images. NOTE: Similarity is actually returned as distance (i.e. dissimilarity) per ITK/ANTs convention. E.g. using Correlation metric, the similarity of an image with itself returns -1.

ANTsR function: imageSimilarity

Parameters:

  • fixed (ants.core.ANTsImage) – the fixed image

  • moving (ants.core.ANTsImage) – the moving image

  • metric_type (str) –

    image metric to calculate

    MeanSquares Correlation ANTSNeighborhoodCorrelation MattesMutualInformation JointHistogramMutualInformation Demons

  • fixed_mask (ANTsImage (optional)) – mask for the fixed image

  • moving_mask (ANTsImage (optional)) – mask for the moving image

  • sampling_strategy (string (optional)) –

    sampling strategy, default is full sampling

    None (Full sampling) random regular

  • sampling_percentage (scalar) – percentage of data to sample when calculating metric Must be between 0 and 1

Return type:

scalar

Example

>>> import ants
>>> x = ants.image_read(ants.get_ants_data('r16'))
>>> y = ants.image_read(ants.get_ants_data('r30'))
>>> metric = ants.image_similarity(x,y,metric_type='MeanSquares')