PropLUT Class

The PropLUT class is used to create and store a look-up-table (LUT) of propagators for subsequent faster refocusing to multiple depths using the angular spectrum method. An instance of this class is returned by methods such as Holo.make_propagator_LUT().

The propagators are created at instantiation, and then are extracted as required using the propagator() method.

class pyholoscope.PropLUT(img_size, wavelength, pixel_size, depth_range, num_depths, propagation_method='angular_spectrum', correct_pixel_size=False, source_distance=None, use_numba=True, precision='single')

Stores a propagator look up table (LUT).

The LUT contains angular spectrum propagators for the specified parameters.

__init__(img_size, wavelength, pixel_size, depth_range, num_depths, propagation_method='angular_spectrum', correct_pixel_size=False, source_distance=None, use_numba=True, precision='single')

Creates a propagator look up table (LUT) containing angular spectrum propagators.

Arguments:

img_sizeint or tuple of (int, int)

size of propagators, square or rectangular

wavelength: float

wavelength of light

pixel_sizefloat

physical size of pixels

depth_range: tuple

range of depths to generate propagators for

num_depthsint

number of depths to generate propagators for

Keyword Arguments:

propagation_methodstr

wave propagation model, ‘angular_spectrum’ (default) or ‘fresnel’

correct_pixel_sizebool

if True, applies effective pixel-size correction based on source_distance during propagator generation

source_distancefloat or None

point-source to camera distance, required when correct_pixel_size is True

numbabool

flag to use numba for speed up (default = False)

precisionstr

‘single’ or ‘double’ (default = ‘single’)

propagator(depth)

Returns the propagator from the LUT which is closest to requested depth. If depth is outside the range of the propagators, function returns None.

Parameters:

depthfloat

refocus depth for requested propagator