Classes
class	CrosstalkConfig

class	CrosstalkTask

class	NullCrosstalkTask

Functions
def	extractAmp (image, amp, corner, isTrimmed=False)

def	calculateBackground (mi, badPixels=["BAD"])

def	subtractCrosstalk (exposure, crosstalkCoeffs=None, badPixels=["BAD"], minPixelToMask=45000, crosstalkStr="CROSSTALK", isTrimmed=False, backgroundMethod="None")

def	writeCrosstalkCoeffs (outputFileName, coeff, det=None, crosstalkName="Unknown", indent=2)

Variables
dictionary	X_FLIP

dictionary	Y_FLIP

Function Documentation

◆ calculateBackground()

def lsst.ip.isr.crosstalk.calculateBackground	(	mi,
		badPixels = `["BAD"]`
	)

Calculate median background in image

Getting a great background model isn't important for crosstalk correction,
since the crosstalk is at a low level. The median should be sufficient.

Parameters
----------
mi : `lsst.afw.image.MaskedImage`
    MaskedImage for which to measure background.
badPixels : `list` of `str`
    Mask planes to ignore.

Returns
-------
bg : `float`
    Median background level.

Definition at line 228 of file crosstalk.py.

◆ extractAmp()

def lsst.ip.isr.crosstalk.extractAmp	(	image,
		amp,
		corner,
		isTrimmed = `False`
	)

Return an image of the amp

The returned image will have the amp's readout corner in the
nominated `corner`.

Parameters
----------
image : `lsst.afw.image.Image` or `lsst.afw.image.MaskedImage`
    Image containing the amplifier of interest.
amp : `lsst.afw.table.AmpInfoRecord`
    Amplifier information.
corner : `lsst.afw.table.ReadoutCorner` or `None`
    Corner in which to put the amp's readout corner, or `None` for
    no flipping.
isTrimmed : `bool`
    The image is already trimmed.
    This should no longer be needed once DM-15409 is resolved.

Returns
-------
output : `lsst.afw.image.Image`
    Image of the amplifier in the standard configuration.

Definition at line 196 of file crosstalk.py.

◆ subtractCrosstalk()

def lsst.ip.isr.crosstalk.subtractCrosstalk	(	exposure,
		crosstalkCoeffs = `None`,
		badPixels = `["BAD"]`,
		minPixelToMask = `45000`,
		crosstalkStr = `"CROSSTALK"`,
		isTrimmed = `False`,
		backgroundMethod = `"None"`
	)

Subtract the intra-detector crosstalk from an exposure

We set the mask plane indicated by ``crosstalkStr`` in a target amplifier
for pixels in a source amplifier that exceed `minPixelToMask`. Note that
the correction is applied to all pixels in the amplifier, but only those
that have a substantial crosstalk are masked with ``crosstalkStr``.

The uncorrected image is used as a template for correction. This is good
enough if the crosstalk is small (e.g., coefficients < ~ 1e-3), but if it's
larger you may want to iterate.

This method needs unittests (DM-18876), but such testing requires
DM-18610 to allow the test detector to have the crosstalk
parameters set.

Parameters
----------
exposure : `lsst.afw.image.Exposure`
    Exposure for which to subtract crosstalk.
crosstalkCoeffs : `numpy.ndarray`
    Coefficients to use to correct crosstalk.
badPixels : `list` of `str`
    Mask planes to ignore.
minPixelToMask : `float`
    Minimum pixel value (relative to the background level) in
    source amplifier for which to set ``crosstalkStr`` mask plane
    in target amplifier.
crosstalkStr : `str`
    Mask plane name for pixels greatly modified by crosstalk.
isTrimmed : `bool`
    The image is already trimmed.
    This should no longer be needed once DM-15409 is resolved.
backgroundMethod : `str`
    Method used to subtract the background.  "AMP" uses
    amplifier-by-amplifier background levels, "DETECTOR" uses full
    exposure/maskedImage levels.  Any other value results in no
    background subtraction.

Definition at line 255 of file crosstalk.py.

◆ writeCrosstalkCoeffs()

def lsst.ip.isr.crosstalk.writeCrosstalkCoeffs	(	outputFileName,
		coeff,
		det = `None`,
		crosstalkName = `"Unknown"`,
		indent = `2`
	)

Write a yaml file containing the crosstalk coefficients

The coeff array is indexed by [i, j] where i and j are amplifiers
corresponding to the amplifiers in det

Parameters
----------
outputFileName : `str`
    Name of output yaml file
coeff : `numpy.array(namp, namp)`
    numpy array of coefficients
det : `lsst.afw.cameraGeom.Detector`
    Used to provide the list of amplifier names;
    if None use ['0', '1', ...]
ccdType : `str`
    Name of detector, used to index the yaml file
    If all detectors are identical could be the type (e.g. ITL)
indent : `int`
    Indent width to use when writing the yaml file

Definition at line 349 of file crosstalk.py.

Variable Documentation

◆ X_FLIP

dictionary lsst.ip.isr.crosstalk.X_FLIP

Initial value:

1 = {lsst.afw.cameraGeom.ReadoutCorner.LL: False, lsst.afw.cameraGeom.ReadoutCorner.LR: True,

2 lsst.afw.cameraGeom.ReadoutCorner.UL: False, lsst.afw.cameraGeom.ReadoutCorner.UR: True}

Definition at line 185 of file crosstalk.py.

◆ Y_FLIP

dictionary lsst.ip.isr.crosstalk.Y_FLIP

Initial value:

1 = {lsst.afw.cameraGeom.ReadoutCorner.LL: False, lsst.afw.cameraGeom.ReadoutCorner.LR: False,

2 lsst.afw.cameraGeom.ReadoutCorner.UL: True, lsst.afw.cameraGeom.ReadoutCorner.UR: True}

Definition at line 187 of file crosstalk.py.

Classes

Functions

Variables