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NOISECHISEL(1) User Commands NOISECHISEL(1)

NAME

NoiseChisel - detect signal in a noisy image

SYNOPSIS

astnoisechisel [OPTION...] ASTRdata

DESCRIPTION

NoiseChisel is part of GNU Astronomy Utilities 0.22. NoiseChisel Detects and segments signal that is deeply burried in noise. It employs a noise-based detection and segmentation method enabling it to be very resilient to the rich diversity of shapes in astronomical targets.

For more information, please run any of the following commands. In particular the second contains a very comprehensive explanation of NoiseChisel's invocation: expected input(s), output(s), and a full description of all the options.

$ astnoisechisel -P
$ info astnoisechisel
$ info NoiseChisel
$ info gnuastro

If you couldn't find your answer in the manual, you can get direct help from experienced Gnuastro users and developers. For more information, please run:

$ info help-gnuastro

NoiseChisel options:

Input:
HDU/extension of convolved image in file.
Convolved image file to avoid convolution.
Extension name or number of input data.
HDU containing kernel image.
Filename of kernel to convolve with input
HDU containing wide kernel image.
Filename of wider kernel for better qthresh
Tessellation (tile grid):
Tile IDs in an image, the size of input.
Fraction of remainder to split last tile.
Interpolation metric (radial, manhattan).
No. of neighbors to use for interpolation.
Only interpolate over the blank tiles.
Sim. to --tilesize, but for larger tiles.

-M, --numchannels=INT[,..] No. of channels in dim.s (FITS order).

Display 1 element/tile, not full input res.
Work (not tile) over channel edges.
Regular tile size on dim.s (FITS order).
Output:
Don't delete output if it exists.
Don't write input's blanks in tiled output.
Keep input directory for automatic output.
Label/count detected pixels that are connected.
No Git commit in 0-th HDU of output FITS.
No metadata in 0-th HDU of output FITS.
No 'DATE' in 0-th HDU of output FITS.
No versions in 0-th HDU of output FITS.
Output file name.
Output only detection labels & 1-elem/tile grid.
'txt', 'fits-ascii', 'fits-binary'.
WCS linear matrix of output ('pc' or 'cd').
Detection:
Num neighboring tiles to look for outlier.
Blanks are foreground in erosion and opening.
Min. fraction of undetected area in tile.
Save all the detection steps to a file.
Save Sky value estimation for pseudo-dets.
Save quantile threshold estimation in file.
Final sky and its STD steps in a file.
Save pseudo-detection S/N values to a file.
Remove small S/N grown detections.
Quantile in pseudo-det. to define true.
Max. area of holes after growth to fill.
Depth of opening after dthresh.
4 or 8 connectivity for dthresh opening.
Minimum quant. to expand true detections.
Connectivity in erosion (number of ngbs).
Number of erosions after thresholding.
4 or 8 connectivity for filling holes.
Minimum number for S/N estimation.
Min. pseudo-detection area for S/N dist.
Quantile for no erosion.
Connectivity in opening (number of ngbs).

--outliersclip=FLT,FLT Sigma-clip params for qthresh outliers.

Multiple of sigma to define outliers.
4 or 8 neighbors for labeling pseudo-dets.
Depth of opening after erosion.
Max. mean and median quant diff. per tile.
Sigma threshold for Pseudo-detections.
No blanks in tile undetected frac. (minskyfrac).
Flat kernel width to smooth interpolated.
Manually input pseudo-det S/N threshold.
Sigma multiple and, tolerance or number.
Quantile threshold on convolved image.
Operating modes:
-?, --help
give this help list
List all config files and variables read.
BibTeX citation for this program.
Read configuration file STR immediately.
Custom prefix of option names config files.
Continue processing after checks.
Do not parse any more configuration files.
Min. bytes to avoid RAM automatically.
Number of CPU threads to use.
Only run if the program version is STR.
Print parameter values to be used and abort.
Don't print mmap'd file's name and size.
Only report errors, remain quiet about steps.
Set default values for this directory and abort.
give a short usage message
Set default values for this user and abort.
print program version

Mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options.

GNU Astronomy Utilities home page: http://www.gnu.org/software/gnuastro/

REPORTING BUGS

Report bugs to bug-gnuastro@gnu.org.

COPYRIGHT

Copyright © 2015-2024 Free Software Foundation, Inc. License GPLv3+: GNU General public license version 3 or later.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

Written/developed by Mohammad Akhlaghi

SEE ALSO

The full documentation for NoiseChisel is maintained as a Texinfo manual. If the info and NoiseChisel programs are properly installed at your site, the command

info NoiseChisel

should give you access to the complete manual.

February 2024 GNU Astronomy Utilities 0.22