Remove Unresponsive And Fluctuating Rings

Description

Method working in the sinogram space to remove ring artifacts caused by dead pixels.

• Plugin documention and guidelines on use

Parameters

in_datasets:
    visibility: datasets
    dtype: "[list[],list[str]]"
    description:
        summary: A list of the dataset(s) to process.
        verbose: A list of strings, where each string gives the name of a dataset that was either specified by a loader plugin or created as output to a previous plugin.  The length of the list is the number of input datasets requested by the plugin.  If there is only one dataset and the list is left empty it will default to that dataset.
    default: "[]"

out_datasets:
    visibility: datasets
    dtype: "[list[],list[str]]"
    description:
        summary: A list of the dataset(s) to create.
        verbose: A list of strings, where each string is a name to be assigned to a dataset output by the plugin. If there is only one input dataset and one output dataset and the list is left empty, the output will take the name of the input dataset. The length of the list is the number of output datasets created by the plugin.
    default: "[]"

size:
    visibility: basic
    dtype: int
    description: Size of the median filter window. Greater is stronger.
    default: "51"

snr:
    visibility: basic
    dtype: float
    description: Ratio used to detect locations of large stripes. Greater is less sensitive.
    default: "3.0"

residual:
    visibility: intermediate
    dtype: bool
    description: Removing residual stripes if True.
    default: "True"

Key

visibility: The visibility level of the parameter
dtype: The type of data
description: A short explanation of the parameter
default: The default value
options: A list of permitted values
dependency: The name of the parameter and value which this parameter depends upon
range: A guide for the range of the parameter

Citations

Superior techniques for eliminating ring artifacts in X-ray micro-tomography by Vo, Nghia T et al.

Bibtex

@article{vo2018superior,
title = {Superior techniques for eliminating ring artifacts in X-ray micro-tomography},
author={Vo, Nghia T and Atwood, Robert C and Drakopoulos, Michael},
journal={Optics express},
volume={26},
number={22},
pages={28396--28412},
year={2018},
publisher={Optical Society of America}}

Endnote

%0 Journal Article
%T Superior techniques for eliminating ring artifacts in X-ray micro-tomography
%A Vo, Nghia T
%A Atwood, Robert C
%A Drakopoulos, Michael
%J Optics express
%V 26
%N 22
%P 28396-28412
%@ 1094-4087
%D 2018
%I Optical Society of America

API

class RemoveUnresponsiveAndFluctuatingRings

detect_stripe(listdata, snr)

Algorithm 4 in the paper. To locate stripe positions.

Parameters

• listdata (1D normalized array.) –

• snr (Ratio (>1.0) used to detect stripe locations.) –

Returns

listmask

Return type

1D binary mask.

pre_process()

This method is called immediately after base_pre_process().

process_frames(data)

This method is called after the plugin has been created by the pipeline framework and forms the main processing step

Parameters

data (list(np.array)) – A list of numpy arrays for each input dataset.

remove_large_stripe(matindex, sinogram, snr, size)

Algorithm 5 in the paper. To remove large stripes.

Parameters

• sinogram (2D array.) –

• snr (Ratio (>1.0) used to detect stripe locations.) –

• size (Window size of the median filter.) –

Returns

sinogram

Return type

stripe-removed sinogram.

setup()

This method is first to be called after the plugin has been created. It determines input/output datasets and plugin specific dataset information such as the pattern (e.g. sinogram/projection).