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[gnuastro-devel] [bug #53825] NoiseChisel not accounting for fully zero-
From: |
Mohammad Akhlaghi |
Subject: |
[gnuastro-devel] [bug #53825] NoiseChisel not accounting for fully zero-valued tiles |
Date: |
Thu, 3 May 2018 14:07:09 -0400 (EDT) |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:59.0) Gecko/20100101 Firefox/59.0 |
URL:
<http://savannah.gnu.org/bugs/?53825>
Summary: NoiseChisel not accounting for fully zero-valued
tiles
Project: GNU Astronomy Utilities
Submitted by: makhlaghi
Submitted on: Thu 03 May 2018 08:07:06 PM CEST
Category: NoiseChisel
Severity: 3 - Normal
Item Group: Crash
Status: In Progress
Privacy: Public
Assigned to: makhlaghi
Open/Closed: Open
Discussion Lock: Any
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Details:
It might happen that the input dataset has zero values for regions with no
data: essentially using zero as a mask value. In other detection methods (that
have above-Sky thresholds) this isn't an issue. But NoiseChisel's threshold is
below the Sky value, so the zero valued pixels will actually be considered as
detections. We therefore encourge users to set zero valued pixels to
NaN/blank.
When there are tiles with fully zero-valued pixels, they may thus be used for
estimating the pseudo-detection Sky and Sky STD and result in zero-valued Sky
(and its STD) values. This will later cause the counts-per-second correction
(`cpscorr') to be zero and produce `inf' S/N values.
It is thus necessary to also mask tiles that pass all other tests, but produce
a standard deviation of 0.
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- [gnuastro-devel] [bug #53825] NoiseChisel not accounting for fully zero-valued tiles,
Mohammad Akhlaghi <=