Function lsst::afw::geom::makeModifiedWcs

Function Documentation

std::shared_ptr<SkyWcs> lsst::afw::geom::makeModifiedWcs(TransformPoint2ToPoint2 const &pixelTransform, SkyWcs const &wcs, bool modifyActualPixels)

Create a new SkyWcs whose pixels are transformed by pixelTransform, as described below.

If modifyActualPixels is true and the cameraGeom::ACTUAL_PIXELS frame exists then pixelTransform is inserted just after the cameraGeom::ACTUAL_PIXELS frame: 

newActualPixelsToPixels = pixelTransform -> oldActualPixelsToPixels

This is appropriate for shifting a WCS, e.g. when writing FITS metadata for a subimage.

If modifyActualPixels is false or the cameraGeom::ACTUAL_PIXELS frame does not exist then pixelTransform is inserted just after the cameraGeom::PIXELS frame: 

newPixelsToIwc = pixelTransform -> oldPixelsToIwc

This is appropriate for inserting a model for optical distortion.

Other than the change described above, the new SkyWcs will be just like the old one.

Return

the new WCS

Parameters

  • [in] pixelTransform: Transform to insert

  • [in] wcs: Input WCS

  • [in] modifyActualPixels: Location at which to insert the transform; if true and the cameraGeom::ACTUAL_PIXELS frame is present then insert just after the cameraGeom::ACTUAL_PIXELS frame, else insert just after the cameraGeom::PIXELS frame.