pyramid-laplacian

pyramid_laplacian

skimage.transform.pyramid_laplacian(image, max_layer=-1, downscale=2, sigma=None, order=1, mode='reflect', cval=0) [source]

Yield images of the laplacian pyramid formed by the input image.

Each layer contains the difference between the downsampled and the downsampled, smoothed image:

layer = resize(prev_layer) - smooth(resize(prev_layer))

Note that the first image of the pyramid will be the difference between the original, unscaled image and its smoothed version. The total number of images is max_layer + 1. In case all layers are computed, the last image is either a one-pixel image or the image where the reduction does not change its shape.

Parameters:

image : array Input image. max_layer : int Number of layers for the pyramid. 0th layer is the original image. Default is -1 which builds all possible layers. downscale : float, optional Downscale factor. sigma : float, 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. order : int, 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’. cval : float, optional Value to fill past edges of input if mode is ‘constant’.

Returns:

pyramid : generator Generator yielding pyramid layers as float images.

References

[R378]

http://web.mit.edu/persci/people/adelson/pub_pdfs/pyramid83.pdf

[R379]

http://sepwww.stanford.edu/~morgan/texturematch/paper_html/node3.html