pynrc.reduce.ref_pixels.channel_smooth_butter¶

pynrc.reduce.ref_pixels.channel_smooth_butter(im_arr, order=3, freq=0.1, per_line=False, mask=None)[source]¶

Channel smoothing using Butterworth filter

Parameters

im_arr (ndarray) – Input array of images (intended to be a cube of output channels). Each image is operated on separately. If only two dimensions, then only a single input image is assumed.

Keyword Arguments

order (int) – Order of the filter (high order have sharper frequency cut-off)
freq (float) – Normalized frequency cut-off (between 0 and 1). 1 is Nyquist.
per_line (bool) – Smooth each channel line separately with the hopes of avoiding edge discontinuities.
mask (bool image or None) – An image mask of pixels to ignore. Should be same size as im_arr. This can be used to mask pixels that the filter should ignore, such as stellar sources or pixel outliers.