Bug #1113
closed
oficonv creates illegal characters when converting from ISO_IR 192 to ISO_IR 101
100%
Description
When converting a string that contains greek letters from Unicode (ISO_IR 192) to Latin-2 (ISO_IR 101), oficonv does not report an error for characters that cannot be converted, but instead writes a weird byte sequence "bd\b4\2f\34" for each character.
The problem can be demonstrated by converting the attached sample file to Latin-2:
dcmconv +C "ISO_IR 101" unicode_with_greek_chars.dcm - | dcmdump - --search PatientName
Apparently, Latin-3 (ISO-IR 109) and Latin-4 (ISO-IR 110) are also affected, while Latin-1 (ISO_IR 100) is not.
Reported 2024-03-07 by Fabian Günther, see https://forum.dcmtk.org/viewtopic.php?t=5367
Files
Updated by Marco Eichelberg over 1 year ago
Apparently, this is caused by incorrect translation tables, in this case oficonv/datasrc/csmapper/ISO-8859/UCS%ISO-8859-2.src.
This is remarkable, because these tables come from the latest FreeBSD source, without any modification.
Updated by Marco Eichelberg over 1 year ago
- File check_iso8859_mapping_table.pl check_iso8859_mapping_table.pl added
- Status changed from New to Closed
- Assignee set to Marco Eichelberg
- % Done changed from 0 to 100
- Estimated time set to 4:00 h
The iconv mapping tables from Unicode to ISO-8859-2 and ISO-8859-3 contained many incorrect mappings where characters not available in the ISO character set were mapped to four character sequences essentially containing garbage. This has now been fixed by removing all mappings to four-byte character sequences that were not also present in the other ISO-8859 mapping tables.
These issues are also present in the original FreeBSD source from which oficonv has been ported. They have been reported to FreeBSD: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=278229
I have written a small (primitive) Perl script for visualizing the mapping tables. This is attached to this issue and may be useful for similar reports in the future.
Closed by commit #5d7495d8c.