CFITSIO Changelog

What's new in CFITSIO 3.33

• Modified the imcomp_decompress_tile routine to ignore any numerical overflows that might occur when using Hcompress to decompress the image. If Hcompress is used in its 'lossy' mode, the uncompressed image pixel values may slightly exceed the range of an integer*2 variable. This is generally of no consequence, so we can safely ignore any overflows in this case and just clip the values to the legal range.
• The default tiling pattern when writing a tile-compressed image has been changed. The old behaviour was to compress the whole image as one single large tile. This is often not optimal when dealing with large images, so the new default behavior is to treat each row of the image as one tile. This is the same default behavior as in the standalone fpack program. The default tile size can be overridden by calling fits_set_tile_dim.
• Fixed bug bug that resulted in a corrupted output FITS image when attempting to write a float or double array of values to a tile-compressed integer data type image. CFITSIO does not support implicit data type conversion in this case and now correctly returns an appropriate error status.
• Modified ricecomp.c to define the nonzero_count lookup table as an external variable, rather then dynamically allocating it within the 3 routines that use it. This simplifies the code and eliminates the need for special thread locking and unlocking statements.
• Modifed how the uncompressed size of a gzipped file is computed in the mem_compress_open routine in drvrmem.c. Since gzip only uses 4 bytes in the compressed file header to store the original file size, one may need to apply a modulo 2^32 byte correction in some cases. The logic here was modified to allow for corner cases (e.g., very small files, and when running on 32-bit platforms that do not support files larger than 2^31 bytes in size).
• Added new public routine to construct a 80 keyword record from the 3 input component strings, i.e, the keyword name string, the value string, and the comment string: fits_make_key/ffmkky. (This was already an undocumented internal routine in previous versions of CFITSIO).
• Modified ffc2s so that if the input keyword value string is a null string, then it will return a VALUE_UNDEFINED (204) status value. This makes it consistent with the behavior when attempting to read a null keyword which has no value) as a logical or as a number (which also returns the 204 error). This should only affect cases where the header keyword does not have an equal sign followed by a space character in columns 9 and 10 of the header record.
• Changed the "char *" parameter declarations to "const char *" in many of the routines (mainly the routines that modify or update keywords) to avoid compiler warnings or errors from C++ programs that tend to be more rigorous about using "const char *" when appropriate.
• Added support for caching uncompressed image tiles, so that the tile does not need to be uncompressed again if the application program wants to read more data from the same tile. This required changes to the main FITS file structure that is defined in fitsio.h, as well as changes to imcompress.c.
• Enhanced the previous modification to drvrfile.c to handle additional user cases when running in the HEASARC's Hera environment.