# DrizzlePac Release Notes¶

The version of DrizzlePac can be identified using

> python
>>> import drizzlepac
>>> drizzlepac.__version__


The following notes provide some details on what has been revised for each version in reverse chronological order (most recent version at the top of the list).

## 3.1.9 (unreleased)¶

• Update runastrodriz to work under Windows while adding documentation to tell the user to run with num_cores set to 1. [#794]
• Fixed a bug in TweakReg due to which TweakReg would crash when updatehdr was set to False. [#801]

## 3.1.8 (11-Aug-2020)¶

A number of changes have been implemented to either correct problems or improve the processed results. The most significant of the changes are:

• rscale only used for alignment.
• a minimum of 6 sources now gets used for alignment
• no proper motions used in astrometric (GAIA) catalog when attempting a posteriori fitting
• chip-to-chip alignment errors were corrected

In addition to a few dozen bug fixes, the following updates to the algorithms were also implemented.

• Simplified the logic in tweakreg for deciding how to archive primary WCS resulting in a reduction of duplicate WCSes in image headers. [#715]
• Added polynomial look-up table distortion keywords to the list of distortion keywords used by outputimage.deleteDistortionKeywords so that distortions can be removed from ACS images that use NPOLFILE. This now allows removal of alternate WCS from blotted image headers. [#709]
• Added rules_file parameter to AstroDrizzle to enable use of custom files in pipeline processing. [#674]
• Only apply solutions from the astrometry database which were non-aposteriori WCS solutions as the PRIMARY WCS. This allows the pipeline to compare the true apriori WCS solutions (e.g., GSC or HSC WCSs) to aposteriori solutions computed using the latest distortion-models and alignment algorithms being used at the time of processing. [#669]
• Verification using a similarity index gets reported in the trailer file and does not get used as a Pass/Fail criteria for alignment. [#619]
• If verification fails for either pipeline-default or apriori solution, reset cosmic-ray(CR) flag (4096) in DQ arrays. This will allow subsequent attempt to align the images to not be impacted by potentially mis-identified CRs that most likely blanked out real sources in the field. As a result, the image alignment process became more robust when computing the aposteriori alignment. [#614]
• Fix a crash in tweakreg when finding sources in very large images due to a bug in scipy.signal.convolve2d. [#670]
• Fix a bug in tweakreg due to which the number of matched sources needed to be strictly greater than minobj. Now the minimum number of matched sources maust be at least equal or greater than minobj. [#604]
• Fix a crash in tweakreg when 2dhist is enabled and numpy version is 1.18.1 and later. [#583, #587]
• Update calibrated (FLC/FLT) files with RMS and NMATCH keywords when it successfully aligns the data to GAIA using the a posteriori fit. Headerlet files for this fit which already have these keywords are now retained and provided as the final output headerlets as well. [#555]
• Insure HDRNAME keyword gets added to successfully aligned FLC/FLT files. [#580]
• Fix problem with ‘tweakback’ task when trying to work with updated WCS names. [#551]
• Fix problems found in processing data with NGOODPIX==0, DRC files not getting generated for singletons, alignment trying to use a source too near the chip edge, catch the case were all inputs have zero exposure time, lazily remove alignment sub-directories, fixed a bug in overlap computation that showed up in oblong mosaics, recast an input to histogram2d as int, defined default values for tables when no sources were found. [#593]
• Updated to be compatible with tweakwcs v0.6.0 to correct chip-to-chip alignment issues in aposteriori WCS solutions. [#596]
• Correctly define output drizzle product filename during pipeline processing for exposures with ‘drz’ in the rootname. [#523]
• Implement multiple levels of verification for the drizzle products generated during pipeline processing (using runastrodriz); including overlapp difference computations [#520], and magnitude correlation [#512].
• Replace alignimages module with O-O based align [#512]
• Fix problem with NaNs when looking for sources to use for aligning images [#512]
• Fixed code that selected the brightest sources to use for alignment allowing alignment to work (more often) for images with saturated sources. [#512]
• Use logic for defining the PSF extracted from the images to shrink it in each axis by one-half for images of crowded fields to allow for more sources to be extracted by daofind-like algorithm. This enables source finding and alignment to work more reliably on crowded field images. [#512]
• Insure all input files, especially those with zero exposure time or grism images, get updated with the latest pipeline calibration for the distortion. [ #495]

This version also relies on updates in the following packages to get correctly aligned and combined images with correctly specified WCS keywords:

• TWEAKWCS 0.6.4: This version corrects problems with the chip-to-chip separation that arose when applying a single fit solution to the entire observation.
• STWCS 1.5.4: This version implements a couple of fixes to insure that use of headerlets defines the full correct set of keywords from the headerlet for the PRIMARY WCS in the science exposure without introducing multiple copies of some keywords.
• Numpy 1.18: Changes in numpy data type definitions affected some of the code used for computing the offset between images when performing aposteriori alignment during pipeline processing and when running the ‘tweakreg’ task.

## 3.1.3 (5-Dec-2019)¶

• Fixed a bug in the updatehdr.update_from_shiftfile() function that would crash while reading shift files. [#448]
• Migration of the HAP portion of the package to an object-oriented implemenation. [#427]
• Added support for providing HSTWCS object as input to ‘final_refimage’ or ‘single_refimage’ parameter. [#426]
• Implementation of grid definition interface to support returning SkyCell objects that overlap a mosaic footprint. [#425]
• Complete rewrite of runastrodriz for pipeline processing to include multi-level verification of alignment. [#440]

## 3.0.2 (15-Jul-2019)¶

• Removed deprecated parameter coords from the parameter list of pixtopix.tran() function. [#406]
• Modified the behavior of the verbose parameter in pixtopix.tran() to not print coordinates when not run as a script and when output is None. [#406]
• Fixed a compatibility issue in tweakutils that would result in crash in skytopix when converting coordinates in hms format. [#385]
• Fixed a bug in the astrodrizzle.sky module due to which sky matching fails with “Keyword ‘MDRIZSKY’ not found” error when some of the input images do not overlap at all with the other images. [#380]
• Fixed a bug in the util.WithLogging decorator due to which incorrect log file was reported when user-supplied log file name does not have .log extension. [#365]
• Fixed a bug introduced in #364 returning in finally block. [#365]
• Improved util.WithLogging decorator to handle functions that return values. [#364]
• Fixed a bug in the automatic computation of the IVM weights when IVM was not provided by the user. [#320]
• Fixed a bug in the 2D histogram code used for estimating shifts for catalog pre-matching. This may result in better matching. [#286]
• Now tolerance (in tweakreg) is no longer ignored when use2dhist is enabled. [#286]
• Fixed VS compiler errors with pointer artithmetic on void pointers. [#273]
• Fix logic so that code no longer tries to update headers when no valid fit could be determined. [#241]
• Fixed a bug in the computation of interpolated large scale flat field for STIS data. The bug was inconsequential in practice. Removed the dependency on stsci.imagemanip package. [#227]
• Removed the dependency on stsci.ndimage (using scipy routines instead). [#225]
• Added 'Advanced Pipeline Products' alignment code to drizzlepac package. Enhance runastrodriz to compute and apply absolute astrometric corrections to GAIA (or related) frame to images where possible. [#200, #213, #216, #223, #234, #235, #244, #248, #249, #250, #251, #259, #260, #268, #271, #283, #294, #302]
• Add computation and reporting of the fit’s Root-Mean-Square Error (RMSE) and Mean Absolute Error (MAE). [#210]
• Replaced the use of WCS._naxis1 and WCS._naxis2 with WCS.pixel_shape [#207]
• Removed support for Python 2. Only versions >= 3.5 are supported. [#207]
• Use a more numerically stable numpy.linalg.inv instead of own matrix inversion. [#205]
• The intermediate fit match catalog, with the name _catalog_fit.match generated by tweakreg now has correct RA and DEC values for the sources after applying the fit. [#200, #202]
• Simplify logic for determining the chip ID for each source. [#200]

## 2.2.6 (02-Nov-2018)¶

• Fix a bug that results in tweakreg crashing when no sources are found with user-specified source-finding parameters and when tweakreg then attempts to find sources using default parameters. [#181]
• Updated unit_tests to use original inputs, rather than updated inputs used by nightly regression tests.
• Fix numpy “floating” deprecation warnings. [#175]
• Fix incorrect units in CR-cleaned images created by astrodrizzle. Now CR-cleaned images should have the same units as input images. [#190]

## 2.2.5 (14-Aug-2018)¶

• Changed the color scheme of the hist2d plots to viridis. [#167]
• Refactored test suite
• sdist now packages C extension source code

## 2.2.4 (28-June-2018)¶

• Replace pyregion with stregion

## 2.2.3 (13-June-2018)¶

• Updated links in the documentation to point to latest drizzlepac website and online API documentation.
• Code cleanup.
• Updated C code to be more compatible with latest numpy releases in order to reduce numerous compile warnings.
• Updated documentation to eliminate (at this moment) all sphinx documentation generation warnings.
• Moved 'release_notes.rst' to 'CHANGELOG.rst' in the top-level directory.
• Improved setup to allow documentation build. See drizzlepac PR #142 and Issue #129 for more details.
• Fixed a bug in a print statement in the create median step due to which background values for input images used in this step were not printed.
• Fixed a bug due to which TweakReg may have effectively ignored verbose setting.
• Fixed a bug in drizzlepac.util.WithLogging due to which astrodrizzle would throw an error trying when to raise another error. See Issue #157 for more details.

## 2.2.2 (18-April-2018)¶

• Fixed a bug in TweakReg introduced in v2.2.0 due to which, when TweakReg is run from the interpreter, the code may crash when trying to interpret input files.

## 2.2.1 (12-April-2018)¶

• Fixed problems with processing WFPC2 data provided by the archive. User will need to make sure they run updatewcs on all input WFPC2 data before combining them with astrodrizzle.

## 2.2.0 (11-April-2018)¶

• Implemented a major refactor of the project directory structure. Building no longer requires d2to1 or stsci.distutils. Drizzlepac’s release information (i.e. version, build date, etc) is now handled by relic. See https://github.com/spacetelescope/relic
• Added basic support for compiling Drizzlepac’s C extensions under Windows.
• Documentation is now generated during the build process. This ensures the end-user always has access to documentation that applies to the version of drizzlepac being used.
• Swapped the effect of setting configobj to None or 'defaults' in AstroDrizzle and TweakReg. When calling one of these tasks with configobj parameter set to None, values for the not-explicitly-specified parameters should be set to the default values for the task. When configobj is set to 'defaults' not-explicitly-specified parameters will be loaded from the ~/.teal/astrodrizzle.cfg or ~/.teal/tweakreg.cfg files that store latest used settings (or from matching configuration files in the current directory). See https://github.com/spacetelescope/drizzlepac/pull/115 for more details.

## 2.1.22 (15-March-2018)¶

• Changed the definition of Megabyte used to describe the size of the buffer for create median step (combine_bufsize). Previously a mixed (base-2 and base-10) definition was used with 1MB = 1000x1024B = 1024000B. Now 1MB is defined in base-2 (MiB) as 1MB = 1024x1024B = 1048576B.
• Redesigned the logic in createMedian step used to split large single_sci images into smaller chunks: new logic is more straightforward and fixes errors in the old algorithm that resulted in crashes or unnecessarily small chunk sizes that slowed down createMedian step.
• Due to the above mentioned redesign in the logic for splitting large images into smaller chunks, now overlap can be set to 0 if so desired in the minmed combine type. Also, it is automatically ignored (set to 0) for all non-minmed combine types. This will result in additional speed-up in the Create Median step.
• Both AstroDrizzle() and TweakReg() now can be called with configobj parameter set to 'defaults' in order to indicate that values for the not-explicitly-specified parameters should be set to the default values for the task instead of being loaded from the ~/.teal/astrodrizzle.cfg or ~/.teal/tweakreg.cfg files that store latest used settings.
• Updated documentation.

## 2.1.21 (12-January-2018)¶

• Restore recording of correct EXPTIME value in the headers of single drizzled (“single_sci”) images. See https://github.com/spacetelescope/drizzlepac/issues/93 for more details.
• Fixed a bug in drizzlepac due to which user provided combine_lthresh or combine_hthresh in the CREATE MEDIAN IMAGE step were not converted correctly to electrons (processing unit). This bug affected processing of WFPC2, STIS, NICMOS, and WFC3 data. See https://github.com/spacetelescope/drizzlepac/issues/94 for more details.
• Modified print format so that scales, skew and rotations are printed with 10 significant digits while shifts are printed with 4 digits after the decimal point.

## 2.1.17 (13-June-2017)¶

• drizzlepac.adrizzle updated to work with numpy >=1.12 when they implemented more strict array conversion rules for math. Any input which still has INT format will be converted to a float before any operations are performed, explicitly implementing what was an automatic operation prior to numpy 1.12.

## 2.1.16 (05-June-2017)¶

• Fixed a bug introduced in release v2.1.15 in the logic for merging WCS due to which custom WCS scale was being ignored.

## 2.1.15 (26-May-2017)¶

• fits.io operations will no longer use memory mapping in order to reduce the number of file handles used when running either astrodrizzle or tweakreg. See issue #39 for more details.
• Fixed bugs and improved the logic for merging WCS that is used to define astrodrizzle’s output WCS.
• Added crpix1 and crpix2 parameters to custom WCS.

## 2.1.13 (11-Apr-2017)¶

• Fixed a bug due to which sky background was subtracted by astrodrizzle from the images even though skysub was set to False when MDRIZSKY was already present in input images’ headers.

## 2.1.12 (04-Apr-2017)¶

• astrodrizzle now will run updatewcs() on newly created images when necessary, e.g., after converting WAVERED FITS to MEF format (*c0f.fits to *_c0h.fits) or after unpacking multi-imset STIS _flt files. See PR #56 for more details.
• Fixed a bug that was preventing processing STIS image data.
• Fixed a bug in reading user input (see issue #51).

## 2.1.11 (24-Mar-2017)¶

Bug fix release (a bug was introduced in v2.1.10).

## 2.1.10 (23-Mar-2017)¶

Some of the changes introduced in release v2.1.9 were not backward compatible. This release makes those changes backward compatible.

## 2.1.9 (22-Mar-2017)¶

Compatibility improvements with Python 3 and other STScI software packages.

## 2.1.8 (08-Feb-2017)¶

• Drizzlepac code will no longer attempt to delete “original” (WCS key ‘O’) resulting in a decreased number of warnings (see issue #35 ).
• Negative values are now zeroed in the ‘minmed’ step before attempting to estimate Poisson errors (see issue #22).
• Fixed a bug in tweakreg due to incorrect matrix inversion.
• Improved compatibility with astropy.io.fits (‘clobber’ parameter) and numpy which has reduced the number of deprecation warnings).
• Existing static masks in the working directory are now overwritten and not simply re-used (see issue #23).
• Corrected formula for $$\sigma$$ computation in the “create median” step to convert background to electrons before computations. This bug was producing incorrect $$\sigma$$ for instruments whose gain was different from one.
• Improved astrodrizzle documentation for combine_type parameter which now also documents the formula for $$\sigma$$ computation when combine_type parameter is set to 'minmed'.

## 2.1.6 and 2.1.7rc (15-Aug-2016)¶

Package maintenance release.

## 2.1.5 (09-Aug-2016)¶

Technical re-release of v2.1.4.

## 2.1.4 (01-Jul-2016)¶

The following bug fixes have been implemented:

• tweakreg crashes when run with a single input image and a reference catalog.
• Fixes an issue due to which tweakreg, when updating image headers, would not add ‘-SIP’ suffix to CTYPE

## 2.1.3 (16-Mar-2016)¶

• Improved ASN input file handling.
• astrodrizzle does not delete d2imfile anylonger allowing multiple runs of updatewcs on the same WFPC2 image, see Ticket 1244 for more details.
• Allow exclusion regions in tweakreg to be in a different directory and allow relative path in exclusion region file name.
• Improved handling of empty input image lists.
• tweakreg bug fix: use absolute value of polygon area.

## 2.1.2 (12-Jan-2016)¶

• runastrodriz moved to drizzlepac from acstools and wfc3tools packages.
• Improved logic for duplicate input detection.
• Improved logic for handling custom WCS parameters in astrodrizzle.
• Compatibility improvements with Python 3.

## 2.1.1¶

Available under SSBX/IRAFX starting: Nov 17, 2015

This release includes the following bug fixes:

• Resolved order of operation problems when processing WFPC2 data with DGEOFILEs.
• The conversion of the WFPC2 DGEOFILE into D2IMFILE is now incorporated into STWCS v1.2.3 (r47112, r47113, r47114) rather than a part of astrodrizzle. This requires users to run updatewcs first, then astrodrizzle/tweakreg will work with that WFPC2 data seamlessly (as if they were ACS or WFC3 data).
• Compatibility improvements with Python 3.

## 2.1.0¶

Available under SSBX/IRAFX starting: Nov 2, 2015

This version builds upon the major set of changes implemented in v2.0.0 by not only fixing some bugs, but also cleaning up/changing/revising some APIs and docstrings. The complete list of changes includes:

• [API Change] The ‘updatewcs’ parameter was removed from both the astrodrizzle and tweakreg interactive TEAL interfaces. The ‘updatewcs’ parameter can still be used with the Python interface for both the astrodrizzle. astrodrizzle() and tweakreg. Call the stwcs.updatewcs.updatewcs() function separately before running astrodrizzle or tweakreg.
• [API Change] The stand-alone interface for the blot routine (ablot.blot()) has been revised to work seamlessly with astrodrizzle-generated products while being more obvious how to call it correctly. The help file for this task was also heavily revised to document all the input parameters and to provide an example of how to use the task.
• [API Change] Coordinate transformation task (pixtopix/pixtosky/skytopix) interfaces changed to be more consistent, yet remain backward-compatible for now.
• Both astrodrizzle and tweakreg now return an output CD matrix which has identical cross-terms indicating the same scale and orientation in each axis (an orthogonal CD matrix). This relies on a revision to the stwcs.distortion.utils.output_wcs() function.
• The user interfaces to all 3 coordinate transformation tasks now use ‘coordfile’ as the input file of coordinates to transform. The use of ‘coords’ has been deprecated, but still can be used if needed. However, use of ‘coordfile’ will always override any input provided simultaneously with ‘coords’ parameter. Help files have been updated to document this as clearly as possible for users.
• User-provided list of input catalogs no longer needs to be matched exactly with input files. As long as all input images are included in input catalog list in any order, tweakreg will apply the correct catalog to the correct file.
• tweakreg has been updated to correctly and fully apply source selection criteria for both input source catalogs and reference source catalogs based on fluxmin, fluxmax and nbright for each.
• All use of keyword deletion has been updated in drizzlepac (and fitsblender) to avoid warnings from astropy.
• All 3 coordinate transformation tasks rely on the input of valid WCS information for the calculations. These tasks now warn the user when it could not find a valid WCS and instead defaulted to using a unity WCS, so that the user can understand what input needs to be checked/revised to get the correct results.
• Exclusion/inclusion region files that can be used with tweakreg can now be specified in image coordinates and sky coordinates and will only support files written out using DS9-compatible format.
• The filename for ‘final_refimage’ in astrodrizzle and ‘refimage’ in tweakreg can now be specified with OR without an extension, such as ‘[sci,1]’ or ‘[0]’. If no extension is specified, it will automatically look for the first extension with a valid HSTWCS and use that. This makes the use of this parameter in both place consistent and more general than before.
• The reported fit as written out to a file has been slightly modified to report more appropriate numbers of significant digits for the results.
• Use of astrolib.coords was removed from drizzlepac and replaced by use of astropy functions instead. This eliminated one more obsolete dependency in our software.
• Code was revised to rely entirely on astropy.wcs instead of stand-alone pywcs.
• Code was revised to rely entirely on astropy.io.fits instead of stand-alone pyfits.
• Added photeq task to account for inverse sensitivity variations across detector chips and/or epochs.
• WFPC2 data from the archive with DGEOFILE reference files will now need to be processed using stwcs.updatewcs before running them through astrodrizzle or tweakreg. This update converts the obsolete, unsupported DGEOFILE correction for the WFPC2 data into a D2IMFILE specific for each WFPC2 observation, then uses that to convert the WCS based on the new conventions used for ACS and WFC3.

This set of changes represents the last major development effort for DrizzlePac in support of HST. Support of this code will continue throughout the lifetime of HST, but will be limited primarily to bug fixes to keep the code viable as Python libraries used by DrizzlePac continue to develop and evolve with the language.

## 2.0.0¶

** Available under SSBX/IRAFX starting:** Aug 4, 2014

This version encompasses a large number of updates and revisions to the DrizzlePac code, including the addition of new tasks and several parameter name changes. The scope of these changes indicates the level of effort that went into improving the DrizzlePac code to make it easier and more productive for users. The most significant updates to the DrizzlePac code include:

• The Python code has been updated to work identically (without change) under both Python 2.7 and Python 3.x.
• Implementing sky matching, a new algorithm for matching the sky across a set of images being combined by astrodrizzle.
• Updating tweakreg to now align full mosaics where some images may not overlap others in the mosaic.
• Added the option to write out single drizzle step images as compressed images (to save disk space for large mosaics, and I/O time for single drizzle step).
• Improved tweakreg residual plots visually while allowing them to be written out automatically when tweakreg gets run in non-interactive mode.
• Renamed parameters in tweakreg and imagefind to eliminate name clashes.
• Added option to select sources based on sharpness/roundness when tweakreg searches for sources.
• Added support for exclusion and inclusion regions arbitrary shape/size when tweakreg searches for sources.
• Added a full set of source detection parameters for reference image to support multi-instrument alignment in tweakreg.
• Added support for new (simpler, more robust) ACS calibration of time-dependent distortion.
• A full 6-parameter general linear fit can now be performed using tweakreg, in addition to shift and rscale.
• Cleaned up logic for sky-subtraction: user can now turn off sky-subtraction with skysub=no, and still specify a user-defined sky value as the skyuser keyword. This will reduce(eliminate?) the need to manually set MDRIZSKY=0.

In addition to these major updates/changes, numerous smaller bugs were fixed and other revisions were implemented which affected a small portion of the use cases, such as:

• headerlet code now accepts lists of files to be updated.
• source sky positions (RA and Dec) now included in match file.
• DQ flags can now be taken into account when performing source finding in tweakreg.
• all intermediate files generated by astrodrizzle will now be removed when using ‘clean’=’yes’.
• a problem was fixed that caused createMedian to crash where there were no good pixels in one of the images (when they did not overlap).
• interpretation of shiftfile now improved to handle arbitrarily-long filenames, rather than being limited to 24 character filenames.
• documentation has been updated, sometimes with a lot more extensive descriptions.

This version of DrizzlePac also requires use of the latest release version of astropy primarily for WCS and FITS I/O support.

## 1.1.16¶

Publicly Released through PyPI: Mar 27, 2014

Available under SSBX/IRAFX starting: Mar 13, 2014

• Support for WFPC2 GEIS input images improved to correctly find the associated DQ images.
• Static mask files created for all chips in an image now get deleted when using the ‘group’ parameter to only drizzle a single chip or subset of chips.
• Fixed problem caused by changes to stsci.tools code so that drizzlepac will reference the correct extensions in input images.

## 1.1.15 (30-Dec-2013)¶

Publicly Released through PyPI: Jan 14, 2014

Available under SSBX/IRAFX starting: Jan 6, 2014

### Bug fixes¶

• Files created or updated by drizzlepac, fitsblender, or STWCS tasks, e.g. tweakreg or apply_headerlet, will now ensure that the NEXTEND keyword value correctly reflects the number of extensions in the FITS file upon completion.

## 1.1.14dev (21-Oct-2013)¶

Installed in OPUS: Dec 11, 2013

Available starting: Oct 28, 2013

### Bug fixes¶

• DQ arrays in input images now get updated with cosmic-ray masks computed by astrodrizzle when run with the parameter in_memory=True. This restored the cosmic-ray masks detected during pipeline processing.

## v1.1.13dev (11-Oct-2013)¶

available starting: Oct 21, 2013

• tweakreg can now be run in ‘batch’ mode. This allows the user to generate plots and have them saved to disk automatically without stopping processing and requiring any user input.

## 1.1.12dev (05-Sep-2013)¶

available starting: Sept 9, 2013

This version fixed a couple of bugs in astrodrizzle; namely,

• Logic was updated to support pixfrac = 0.0 without crashing. Ths code will now automatically reset the kernel to ‘point’ in that case.
• astrodrizzle now forcibly removes all OPUS WCS keywords from drizzle product headers.
• Default rules for generating drizzle product headers (as used in the archive) were modified to add definitions for ‘float_one’, ‘int_one’, ‘zero’ that generate output values of 1.0, 1, and 0 (zero) respectively for use as keyword values. This allows the LTM* rules to replace ‘first’ with ‘float_one’ so that the physical and image coordinates for drizzle products are consistent.

Additionally, changes were made to STWCS for reprocessing use:

• Problems with using apply_headerlet_as_primary() from the STWCS package on WFPC2 data have been corrected in this revision.

## 1.1.11dev (05-Jul-2013)¶

Available starting: July 15, 2013

• AstroDrizzle now can process all STIS data without crashing.

## 1.1.10dev (06-Feb-2013)¶

available starting: May 6, 2013

• The output drizzle image header no longer contains references to D2IM arrays. This allows tweakreg to work with drizzled images as input where 2-D D2IM corrections were needed.
• Deprecated references to PyFITS .has_key() methods were also removed from the entire package, making it compatible with PyFITS 3.2.x and later.

## 1.1.8dev (06-Feb-2013)¶

available starting: Feb 11, 2013

• Fixed a bug in astrodrizzle which caused blot to raise an exception when using ‘sinc’ interpolation.
• Cleaned up the logic for writing out the results from the pixtopix, pixtosky, and skytopix tasks to avoid an Exception when a list of inputs are provided and no output file is specified.
• A new parameter was added to the tweakback task to allow a user to specify the value of WCSNAME when updating the FLT images with a new solution from a DRZ image header.
• Code in tweakback for updating the header with a new WCS will now automatically generate a unique WCSNAME if the there is a WCS solution in the FLT headers with the default or user-defined value of WCSNAME.

## 1.1.7dev (18-Dec-2012)¶

available starting: Feb 4, 2013

• Updated astrodrizzle to work with input images which do not have WCSNAME defined. This should make it easier to support non-HST input images in the future.
• cleared up confusion between flux parameters in imagefindpars and catalog inputs in tweakreg.
• turned of use of fluxes for trimming input source catalogs when no flux column can be found in input source catalogs.

## 1.1.7dev (18-Dec-2012)¶

available starting: Dec 10, 2012

• Update tweakreg 2d histogram building mode to correctly find the peak when all the inputs match with the same offset (no spurious sources in either source catalog).
• Fixed a bug so that Ctrl-C does not cause an exception when used while tweakreg is running.
• revised the source finding logic to ignore sources near the image edge, a change from how daofind works (daofind expands the image with blanks then fits anyway).
• created a new function to apply the nsigma separation criteria to (try to) eliminate duplicate entries for the same source from the source list. It turns out daofind does have problems with reporting some duplicate sources as well. This function does not work perfectly, but works to remove nearly all (if not all) duplicates in most cases.

## 1.1.7dev (8-Jan-2012)¶

available starting: Jan 14, 2013

• Bug fixed in updatehdr module to allow shiftfiles without RMS columns to work as inputs to manually apply shifts to headers of input images.
• Revised astrodrizzle to update WCS of all input images BEFORE checking whether or not they are valid. This ensures that all files provided as input to astrodrizzle in the pipeline have the headers updated with the distortion model and new WCS.
• Images with NGOODPIX=0 now identified for WFC3 and WFPC2 inputs, so they can be ignored during astrodrizzle processing.
• Replaced 2d histogram building code originally written in Python with a C function that run about 4x faster.

## 1.1.6dev (5-Dec-2012)¶

available starting: Dec 10, 2012

• tweakreg v1.1.0 source finding algorithm now runs many times faster (no algorithmic changes). No changes have been made yet to speed up the 2d histogram source matching code.
• The ‘pixtopix’ task was updated to make the ‘outimage’ parameter optional by using the input image as the default. This required no API changes, but the help files were updated.
• Very minor update to guard against MDRIZTAB being specified without any explicit path.
• Update astrodrizzle to correctly report the exposure time, exposure start, and exposure end for the single drizzle products, in addition to insuring the final drizzle values remain correct.
• astrodrizzle also includes initial changes to safeguard the C code from getting improperly cast values from the configObj(TEAL) input.

## 1.1.5dev (23-Oct-2012)¶

available starting: Oct 29, 2012

• Scaling of sky array for WFC3/IR IVM generation now correct.
• template mask files for WFPC2 no longer generated so that WFPC2 data can now be processed using num_cores > 1 (parallel processing).
• interpretation of the ‘group’ parameter fixed to support a single integer, a comma-separated list of integers or a single ‘sci,<n>’ value. The values correspond to the FITS extension number of the extensions that should be combined. This fix may also speed up the initialization step as more direct use of pyfits was implemented for the interpretation of the ‘group’ parameter.

## 1.1.1 (31-Aug-2012)¶

available starting: Sept 26, 2012

The HST Archive and operational calibration pipeline started using this version on Sept 26, 2012.

## 1.1.4dev (20-Sep-2012)¶

available starting: Sept 24, 2012

• Bug fixed to allow use of final_wht_type=IVM for processing WFPC2 data.
• Revised Initialization processing to speed it up by using more up-to-date, direct pyfits calls.

## 1.1.3 (7-Sep-2012)¶

available starting: Sept 17, 2012

• Fixed the logic so that crclean images always get created regardless of the value of the ‘clean’ parameter.

## 1.1.2 (5-Sep-2012)¶

available starting: Sept 10, 2012

• Remove the restriction of only being able to process images which have WCSNAME keyword as imposed by r15631. The removal of this restriction will now allow for processing of non-updated input files with updatewcs=False for cases where no distortion model exists for the data (as required by CADC).
• Added log statements reporting what sky value was actually used in the drizzle and blot steps

## 1.1.1 (30-Aug-2012)¶

available starting: Sept 3, 2012

• Major revision to astrodrizzle allowing the option to process without writing out any intermediate products to disk. The intermediate products remain in memory requiring significantly more memory than usual. This improves the overall processing time by eliminating as much disk activity as possible as long as the OS does not start disk swapping due to lack of RAM.
• revised to turn off ‘updatewcs’ when coeffs=False(no) so that exposures with filter combinations not found in the IDCTAB will not cause an error.

## 1.0.7 (21-Aug-2012)¶

available starting: Aug 27, 2012

• Fixes problems with missing single_sci images.
• Static mask step revised to skip updates to static mask if all pixel data falls within a single histogram bin. This avoids problems with masking out entire images, which happens if low S/N SBC data is processed with static_mask=yes.

## 1.0.6 (14-Aug-2012)¶

available starting: Aug 20, 2012

Use of IVM for final_wht now correct, as previous code used wrong inputs when IVM weighting was automatically generated by astrodrizzle.

## 1.0.5 (8-Aug-2012)¶

available starting: Aug 13, 2012

• Completely removed the use of the TIME arrays for weighting IR drizzle products so that the photometry for saturated sources in drizzled products now comes out correct.
• Corrected a problem with astrodrizzle which affected processing of WFPC2 data where CRPIX2 was not found when creating the output single sci image.

## 1.0.2 (13-July-2012)¶

available starting: Aug 3, 2012

Pipeline and archive first started using astrodrizzle by processing WFC3 images.