pds4_tools.extern.zscale module

zscale(image, nsamples=1000, contrast=0.25, bpmask=None, zmask=None)

Implement IRAF zscale algorithm

Parameters:

image : arr

2-d numpy array

nsamples : int (Default: 1000)

Number of points in array to sample for determining scaling factors

contrast : float (Default: 0.25)

Scaling factor for determining min and max. Larger values increase the difference between min and max values used for display.

bpmask : None

Not used at this time

zmask : None

Not used at this time

Returns:

(z1, z2)

zsc_sample(image, maxpix, bpmask=None, zmask=None)

zsc_fit_line(samples, npix, krej, ngrow, maxiter)

zsc_compute_sigma(flat, badpix, npix)