Bright Start Mask creation from the .reg files

desprezg · July 4, 2018, 9:04am

Following the discussion in Nyons about emulateHscCoadd.py, @jcoupon and I would like to know which functions of the pipeline we should use to be able to create the masks from the BrightStarMask.reg files.

Thanks a lot.

Guillaume

jbosch · July 6, 2018, 12:37pm

It looks like the code to do this is unfortunately baked into AssembleCoaddTask, so it might not be something you can easily run directly on an emulated coadd.

You can, of course, copy it into a separate class. The code starts here:

github.com

lsst/pipe_tasks/blob/master/python/lsst/pipe/tasks/assembleCoadd.py#L370


retStruct = self.assemble(skyInfo, inputData.tempExpRefList, inputData.imageScalerList,
                          inputData.weightList, supplementaryData=supplementaryData)


if self.config.doInterp:
    self.interpImage.run(retStruct.coaddExposure.getMaskedImage(), planeName="NO_DATA")
    # The variance must be positive; work around for DM-3201.
    varArray = retStruct.coaddExposure.getMaskedImage().getVariance().getArray()
    with numpy.errstate(invalid="ignore"):
        varArray[:] = numpy.where(varArray > 0, varArray, numpy.inf)


if self.config.doMaskBrightObjects:
    brightObjectMasks = self.readBrightObjectMasks(dataRef)
    self.setBrightObjectMasks(retStruct.coaddExposure, dataRef.dataId, brightObjectMasks)


if self.config.doWrite:
    self.log.info("Persisting %s" % self.getCoaddDatasetName(self.warpType))
    dataRef.put(retStruct.coaddExposure, self.getCoaddDatasetName(self.warpType))
if self.config.doNImage and retStruct.nImage is not None:
    dataRef.put(retStruct.nImage, self.getCoaddDatasetName(self.warpType) + '_nImage')


return retStruct

with most of the code you’d want to copy here:

github.com

lsst/pipe_tasks/blob/master/python/lsst/pipe/tasks/assembleCoadd.py#L794


    result : `lsst.daf.persistence.butlerSubset.ButlerDataRef`
        Bright object mask from the Butler object, or None if it cannot
        be retrieved.
    """
    try:
        return dataRef.get("brightObjectMask", immediate=True)
    except Exception as e:
        self.log.warn("Unable to read brightObjectMask for %s: %s", dataRef.dataId, e)
        return None


def setBrightObjectMasks(self, exposure, dataId, brightObjectMasks):
    """Set the bright object masks.


    Parameters
    ----------
    exposure : `lsst.afw.image.Exposure`
        Exposure under consideration.
    dataId : `lsst.daf.persistence.dataId`
        Data identifier dict for patch.
    brightObjectMasks : `lsst.afw.table`
        Table of bright objects to mask.

I’ve just created DM-15030 to get this code separated from AssembleCoaddTask so it can be called more easily in the future, but please don’t wait for that, as I’m not sure when it will get scheduled.