MOPEX Online Manual
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Modules: Detect (Outlier)
Namelist Trigger: run_detect_outlier
Output Directory Keyword: DETECT_DIR
Default Output Directory: <output_dir>/Detect
Depends on: Input files; Med Filter (when run as part of outlier detection)
Output Directory Keyword: DETECT_DIR
Default Output Directory: <output_dir>/Detect
Depends on: Input files; Med Filter (when run as part of outlier detection)
PURPOSE
-
Detect
performs image segmentation. This instance
is used only for outlier rejection. In the Overlap pipeline,
it is used to identify bright pixels (both spurious and astronomical) that should not contribute
to the background matching. In the Mosaic pipeline, it is
used for dual outlier detection as one part of several modules which
together identify outliers. These modules include Detect Outlier, Mosaic Projection, Mosaic Dual Outlier, and Level. Detect produces detection maps and
its output will be taken by Mosaic Projection.
PARAMETER BLOCK
-
&DETECT
Detection_Max_Area = 1000,
Detection_Min_Area = 0,
Detection_Threshold = 3,
Threshold_Type = 'simple', &END
INPUTS
Detection_Max_Area: (int) The maximum area of a a single outlier identified in the detection map. If too large, it will be considered an extended object.
Detection_Min_Area: (int) The minimum area of a cluster to be detected.
Detection_Threshold: (float) The number of sigma above the mean for pixels included in clusters. Default value is 3.
Threshold Type: (char) There are three different ways to decide if a cluster of bright pixels will be segmentated into several clusters. The choices are simple, combo and peak (see Image Segmentation).
OUTPUTS
-
Generated Fits Files (*detmap.fits): The
stack of detection maps produced from interpolated BCD images.
Sources with positive signals, including both real science sources and
outliers from cosmic rays and badpixels, are set to the number of the
cluster membership. The background is zero in the segmentation
map.
DISCUSSION
In the Mosaic pipeline, Detect (Outlier) is part of Dual Outlier detection. The detection is performed on the background subtracted images (the output of Med Filter), which are in original pixels. The output is a set of mask images, one per input image, in which pixels corresponding to detected objects are set to a positive value. The mask images are saved in DETECT_DIR (if the keyword delete_intermediate_files is not set, or is set to 0). If mask_bright = 1 is set in the namelist then these masks will be used in the further processing. Following this module, Mosaic Projection takes the output maps and projects them to a common reference frame (the FIF) before the later modules identify true outliers.| Contents | ~ | Previous: Mosaic Modules: Mosaic Interpolate | ~ | Next: Mosaic Modules: Mosaic Projection |
