skimage2.transform.pyramid_reduce#

skimage2.transform.pyramid_reduce(image, downscale=2, sigma=None, order=1, mode='reflect', cval=0, preserve_range=False, *, channel_axis=None)[source]#

Smooth and then downsample image.

Parameters:
imagendarray

Input image.

downscalefloat, optional

Downscale factor.

sigmafloat, optional

Sigma for Gaussian filter. Default is 2 * downscale / 6.0 which corresponds to a filter mask twice the size of the scale factor that covers more than 99% of the Gaussian distribution.

orderint, optional

Order of splines used in interpolation of downsampling. See skimage.transform.warp for detail.

mode{‘reflect’, ‘constant’, ‘edge’, ‘symmetric’, ‘wrap’}, optional

The mode parameter determines how the array borders are handled, where cval is the value when mode is equal to ‘constant’.

cvalfloat, optional

Value to fill past edges of input if mode is ‘constant’.

preserve_rangebool, optional

Whether to keep the original range of values. Otherwise, the input image is converted according to the conventions of img_as_float. Also see https://scikit-image.org/docs/dev/user_guide/data_types.html

channel_axisint or None, optional

If None, the image is assumed to be a grayscale (single channel) image. Otherwise, this parameter indicates which axis of the array corresponds to channels.

Added in version 0.19: channel_axis was added in 0.19.

Returns:
outarray

Smoothed and downsampled float image.

References