Inheritance diagram for lsst.pipe.tasks.maskStreaks.MaskStreaksTask:

Public Member Functions
def	find (self, maskedImage)

def	run (self, maskedImage)

Public Attributes
	edges

	lines

Static Public Attributes
	ConfigClass = MaskStreaksConfig

Detailed Description

Find streaks or other straight lines in image data.

Nearby objects passing through the field of view of the telescope leave a
bright trail in images. This class uses the Kernel Hough Transform (KHT)
(Fernandes and Oliveira, 2007), implemented in `lsst.houghtransform`. The
procedure works by taking a binary image, either provided as put or produced
from the input data image, using a Canny filter to make an image of the
edges in the original image, then running the KHT on the edge image. The KHT
identifies clusters of non-zero points, breaks those clusters of points into
straight lines, keeps clusters with a size greater than the user-set
threshold, then performs a voting procedure to find the best-fit coordinates
of any straight lines. Given the results of the KHT algorithm, clusters of
lines are identified and grouped (generally these correspond to the two
edges of a strea) and a profile is fit to the streak in the original
(non-binary) image.

Definition at line 508 of file maskStreaks.py.

Member Function Documentation

◆ find()

def lsst.pipe.tasks.maskStreaks.MaskStreaksTask.find	(	self,
		maskedImage
	)

Find streaks in a masked image

Parameters
----------
maskedImage : `lsst.afw.image.maskedImage`
    The image in which to search for streaks.

Returns
-------
result : `lsst.pipe.base.Struct`
    Result struct with components:

    - ``originalLines``: lines identified by kernel hough transform
    - ``lineClusters``:  lines grouped into clusters in rho-theta space
    - ``lines``: final result for lines after line-profile fit
    - ``mask``: 2-d boolean mask where detected lines are True

Definition at line 530 of file maskStreaks.py.

     def find(self, maskedImage):
         """Find streaks in a masked image
  
         Parameters
         ----------
         maskedImage : `lsst.afw.image.maskedImage`
             The image in which to search for streaks.
  
         Returns
         -------
         result : `lsst.pipe.base.Struct`
             Result struct with components:
  
             - ``originalLines``: lines identified by kernel hough transform
             - ``lineClusters``:  lines grouped into clusters in rho-theta space
             - ``lines``: final result for lines after line-profile fit
             - ``mask``: 2-d boolean mask where detected lines are True
         """
         mask = maskedImage.getMask()
         detectionMask = (mask.array & mask.getPlaneBitMask(self.config.detectedMaskPlane))
  
         self.edges = self._cannyFilter(detectionMask)
         self.lines = self._runKHT(self.edges)
  
         if len(self.lines) == 0:
             lineMask = np.zeros(detectionMask.shape, dtype=bool)
             fitLines = LineCollection([], [])
             clusters = LineCollection([], [])
         else:
             clusters = self._findClusters(self.lines)
             fitLines, lineMask = self._fitProfile(clusters, maskedImage)
  
         # The output mask is the intersection of the fit streaks and the image detections
         outputMask = lineMask & detectionMask.astype(bool)
  
         return pipeBase.Struct(
             lines=fitLines,
             lineClusters=clusters,
             originalLines=self.lines,
             mask=outputMask,
         )
  

◆ run()

def lsst.pipe.tasks.maskStreaks.MaskStreaksTask.run	(	self,
		maskedImage
	)

Find and mask streaks in a masked image.

Finds streaks in the image and modifies maskedImage in place by adding a
mask plane with any identified streaks.

Parameters
----------
maskedImage : `lsst.afw.image.maskedImage`
    The image in which to search for streaks. The mask detection plane
    corresponding to `config.detectedMaskPlane` must be set with the
    detected pixels.

Returns
-------
result : `lsst.pipe.base.Struct`
    Result struct with components:

    - ``originalLines``: lines identified by kernel hough transform
    - ``lineClusters``:  lines grouped into clusters in rho-theta space
    - ``lines``: final result for lines after line-profile fit

Definition at line 573 of file maskStreaks.py.

     def run(self, maskedImage):
         """Find and mask streaks in a masked image.
  
         Finds streaks in the image and modifies maskedImage in place by adding a
         mask plane with any identified streaks.
  
         Parameters
         ----------
         maskedImage : `lsst.afw.image.maskedImage`
             The image in which to search for streaks. The mask detection plane
             corresponding to `config.detectedMaskPlane` must be set with the
             detected pixels.
  
         Returns
         -------
         result : `lsst.pipe.base.Struct`
             Result struct with components:
  
             - ``originalLines``: lines identified by kernel hough transform
             - ``lineClusters``:  lines grouped into clusters in rho-theta space
             - ``lines``: final result for lines after line-profile fit
         """
         streaks = self.find(maskedImage)
  
         maskedImage.mask.addMaskPlane(self.config.streaksMaskPlane)
         maskedImage.mask.array[streaks.mask] |= maskedImage.mask.getPlaneBitMask(self.config.streaksMaskPlane)
  
         return pipeBase.Struct(
             lines=streaks.lines,
             lineClusters=streaks.lineClusters,
             originalLines=streaks.originalLines,
         )
  

Member Data Documentation

◆ ConfigClass

lsst.pipe.tasks.maskStreaks.MaskStreaksTask.ConfigClass = MaskStreaksConfig

static

Definition at line 526 of file maskStreaks.py.

◆ edges

lsst.pipe.tasks.maskStreaks.MaskStreaksTask.edges

Definition at line 551 of file maskStreaks.py.

◆ lines

lsst.pipe.tasks.maskStreaks.MaskStreaksTask.lines

Definition at line 552 of file maskStreaks.py.

The documentation for this class was generated from the following file:

/j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/pipe_tasks/21.0.0-172-gfb10e10a+18fedfabac/python/lsst/pipe/tasks/maskStreaks.py

Public Member Functions

Public Attributes

Static Public Attributes