lentil.rescale#

lentil.rescale(img, scale, shape=None, mask=None, order=3, mode='nearest', unitary=True)[source]#

Rescale an image by interpolation.

Parameters:

img (array_like) – Image to rescale
scale (float) – Scaling factor. Scale factors less than 1 will shrink the image. Scale factors greater than 1 will grow the image.
shape (array_like or int, optional) – Output shape. If None (default), the output shape will be the input img shape multiplied by the scale factor.
mask (array_like, optional) – Binary mask applied after rescaling. If None (default), a mask is created from the nonzero portions of img. To skip masking operation, set mask = np.ones_like(img)
order (int, optional) – Order of spline interpolation used for rescaling operation. Default is 3. Order must be in the range 0-5.
mode ({'constant', 'nearest', 'reflect', 'wrap'}, optional) – Points outside the boundaries of the input are filled according to the given mode. Default is ‘constant’.
unitary (bool, optional) – Normalization flag. If True (default), a normalization is performed on the output such that the rescaling operation is unitary and image power (if complex) or intensity (if real) is conserved.

Returns:

img – Rescaled image.

Return type:

ndarray

Notes

The post-rescale masking operation should have no real effect on the resulting image but is included to eliminate interpolation artifacts that sometimes appear in large clusters of zeros in rescaled images.