Connection to image mask planes

Catalog pixelFlags_* columns are directly derived from image mask planes. Each mask plane bit in the image propagates to a corresponding pixel flag in the catalog.

The connections between key mask plans and catalog flags are listed in the table below.

Mask Plane	Catalog Flag	Notes
SAT	pixelFlags_saturated	Saturated pixels.
CR	pixelFlags_cr	Cosmic rays (interpolated in final images).
INTRP	pixelFlags_interpolated	Interpolated pixels (from CRs, defects, saturation).
EDGE	pixelFlags_edge	Image edge (single exposures).
SENSOR_EDGE	pixelFlags_sensor_edge	Detector boundaries (coadds).
BAD	pixelFlags_bad	Known bad pixels (detector defects).
SUSPECT	pixelFlags_suspect	Suspect pixels (near saturation).
NO_DATA	pixelFlags_nodata	No data available.
CLIPPED	pixelFlags_clipped	Outlier rejection during coaddition.
REJECTED	(propagates to CLIPPED)	Input visit excluded during coaddition.

Footprint vs center: Flags without Center suffix are set if any pixel in the source footprint has that mask bit. Center flags are set only if a pixel in the central 3x3 box has that bit. For quality filtering, center flags are typically more important since they affect core photometry.

See images-visit-mask-planes and images-deep-coadd-mask-planes for detailed mask plane descriptions.