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nabu.preproc.double_flatfield

source module nabu.preproc.double_flatfield

Classes

  • DoubleFlatField — Init double flat field by summing a series of urls and considering the same subregion of them.

source class DoubleFlatField(shape, result_url=None, sub_region=None, detector_corrector=None, input_is_mlog=True, output_is_mlog=False, average_is_on_log=False, sigma_filter=None, filter_mode='reflect', log_clip_min=None, log_clip_max=None)

Init double flat field by summing a series of urls and considering the same subregion of them.

Parameters

  • shape : tuple — Expected shape of radios chunk to process

  • result_url : url, optional — where the double-flatfield is stored after being computed, and possibly read (instead of re-computed) before processing the images.

  • sub_region : tuple, optional — If provided, this must be a tuple in the form (start_x, end_x, start_y, end_y). Each image will be cropped to this region. This is used to specify a chunk of files. Each of the parameters can be None, in this case the default start and end are taken in each dimension.

  • input_is_mlog : boolean, default True — the input is considred as minus logarithm of normalised radios

  • output_is_mlog : boolean, default True — the output is considred as minus logarithm of normalised radios

  • average_is_on_log : boolean, False — the minus logarithm of the data is averaged the clipping value that is applied prior to the logarithm

  • sigma_filter : optional — if given a high pass filter is applied by signal -gaussian_filter(signal,sigma,filter_mode)

  • filter_mode : optional, default 'reflect' — the padding scheme applied a the borders ( same as scipy.ndimage.filtrs.gaussian_filter)

Methods

source method DoubleFlatField.compute_double_flatfield(radios, recompute=False)

Read the radios and generate the "double flat field" by averaging and possibly other processing.

Parameters

  • radios : array — Input radios chunk.

  • recompute : bool, optional — Whether to recompute the double flatfield if already computed.

source method DoubleFlatField.get_double_flatfield(radios=None, compute=False)

Get the double flat field or a subregion of it.

Parameters

  • radios : array, optional — Input radios chunk

  • compute : bool, optional — Whether to compute the double flatfield anyway even if a dump file exists.

Raises

  • ValueError

source method DoubleFlatField.apply_double_flatfield(radios)

Apply the "double flatfield" filter on a chunk of radios. The processing is done in-place !