Starlet

class scarlet2.Starlet(image, coefficients, generation, convolve2d)

Bases: object

Wavelet transform of a images (2D or 3D) with the ‘a trou’ algorithm.

The transform is performed by convolving the image by a seed starlet: the transform of an all-zero image with its central pixel set to one. This requires 2-fold padding of the image and an odd pad shape. The fft of the seed starlet is cached so that it can be reused in the transform of other images that have the same shape.

Parameters:

• image (array) – Image in real space.

• coefficients (array) – Starlet transform of the image.

• generation (int) – The generation of the starlet transform (either 1 or 2).

• convolve2d (array) – The filter used to convolve the image and create the wavelets. When convolve2d is None this uses a cubic bspline.

property coefficients

Starlet coefficients

static from_image(image, scales=None, generation=2, convolve2d=None)

Generate a set of starlet coefficients for an image

Parameters:

• image (array-like) – The image that is converted into starlet coefficients

• scales (int) – The number of starlet scales to use. If scales is None then the maximum number of scales is used. Note: this is the length of the coefficients-1, as in the notation of Starck et al. 2011.

• generation (int) – The generation of the starlet transform (either 1 or 2).

• convolve2d (array-like) – The filter used to convolve the image and create the wavelets. When convolve2D is None this uses a cubic bspline.

Returns:

result – The resulting Starlet that contains the image, starlet coefficients, as well as the parameters used to generate the coefficients.

Return type:

Starlet

property image

The real space image