Warper

class lsst.afw.math.Warper(warpingKernelName, interpLength=10, cacheSize=1000000, maskWarpingKernelName='', growFullMask=16)

Bases: object

Warp images.

Parameters:
warpingKernelName : str

see WarperConfig.warpingKernelName

interpLength : int, optional

interpLength argument to lsst.afw.math.warpExposure

cacheSize : int, optional

size of computeCache

maskWarpingKernelName : str, optional

name of mask warping kernel (if "" then use warpingKernelName); see WarperConfig.maskWarpingKernelName

growFullMask : int, optional

mask bits to grow to full width of image/variance kernel

Methods Summary

fromConfig(config) Create a Warper from a config.
getMaskWarpingKernel() Get the mask warping kernel.
getWarpingKernel() Get the warping kernel.
warpExposure(destWcs, srcExposure[, border, …]) Warp an exposure.
warpImage(destWcs, srcImage, srcWcs[, …]) Warp an image or masked image.

Methods Documentation

classmethod fromConfig(config)

Create a Warper from a config.

Parameters:
config : WarperConfig

The config to initialize the Warper with.

getMaskWarpingKernel()

Get the mask warping kernel.

getWarpingKernel()

Get the warping kernel.

warpExposure(destWcs, srcExposure, border=0, maxBBox=None, destBBox=None)

Warp an exposure.

Parameters:
destWcs : lsst.afw.geom.SkyWcs

WCS of warped exposure

srcExposure

exposure to warp

border : int, optional

grow bbox of warped exposure by this amount in all directions (in pixels); if negative then the bbox is shrunk; border is applied before maxBBox; ignored if destBBox is not None

maxBBox : lsst.geom.Box2I, optional

maximum allowed parent bbox of warped exposure; if None then the warped exposure will be just big enough to contain all warped pixels; if provided then the warped exposure may be smaller, and so missing some warped pixels; ignored if destBBox is not None

destBBox : lsst.geom.Box2I, optional

exact parent bbox of warped exposure; if None then border and maxBBox are used to determine the bbox, otherwise border and maxBBox are ignored

Returns:
destExposure : same type as srcExposure

warped exposure

Notes

calls lsst.afw.math.warpExposure insted of warpImage because the former copies attributes such as Calib, and that should be done in one place

The PSF is not warped. To warp the PSF, use lsst.meas.algorithms.WarpedPsf

warpImage(destWcs, srcImage, srcWcs, border=0, maxBBox=None, destBBox=None)

Warp an image or masked image.

Parameters:
destWcs : lsst.afw.geom.SkyWcs

WCS of warped image

srcImage

image or masked image to warp

srcWcs : lsst.afw.geom.SkyWcs

WCS of image

border : int, optional

grow bbox of warped image by this amount in all directions (in pixels); if negative then the bbox is shrunk; border is applied before maxBBox; ignored if destBBox is not None

maxBBox : lsst.geom.Box2I, optional

maximum allowed parent bbox of warped image; if None then the warped image will be just big enough to contain all warped pixels; if provided then the warped image may be smaller, and so missing some warped pixels; ignored if destBBox is not None

destBBox : lsst.geom.Box2I, optional

exact parent bbox of warped image; if None then border and maxBBox are used to determine the bbox, otherwise border and maxBBox are ignored

Returns:
destImage : same type as srcExposure

warped image or masked image