Space Telescope Science Institute
DrizzlePac 2012 Handbook
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The DrizzlePac Handbook > Appendix D: Previous Drizzle Software Packages > D.2 First Generation Drizzle IRAF Tasks

D.2 First Generation Drizzle IRAF Tasks
The original Dither package consisted of several separate tasks, executed separately in a specific order, to align observations, as well as detect cosmic rays and other detector defects (see WFPC2 ISR 98-04: The Drizzling Cookbook).
At its heart was the Drizzle task, a set of compiled Fortran code, that was used to combine dithered observations and improve sampling of all the data while using cosmic ray and bad pixel masks created using the other tasks in the dither package. Drizzle relied on the user to provide all necessary inputs for re-sampling the images, including application of distortion coefficients, pixel offsets, rotation or plate scale changes, and the size of the output image. Supplemental tasks were also provided to perform coordinate transformations using the full Drizzle algorithm, instead of going through all the effort of re-sampling images themselves. While these older tasks are no longer supported, their functionality has been incorporated into new scripts used by PyDrizzle, MultiDrizzle, and DrizzlePac.
The following functions are the original IRAF interface routines in the first Dither package, and are no longer supported:

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