Recent Changes in Ghostscript
Highlights in this release include:
The big change in this release is that the old PDF interpreter (written in PostScript) is now fully deprecated. We will not be making any further changes to it. For this release, the
-dNEWPDF=falseoption remains for "emergency" use, but the option to fall back to the old intepreter will also be removed in the next full release (10.01.0) in spring 2023.
So we once again encourage all users to test the new interpreter in their use cases, and report any problems.
The new PDF interpreter written in C has had several performance improvements. It was already quicker for the majority of cases than the PostScript implementation, but we found further improvements for common cases, and also several speed improvements in edge cases.
Our efforts in code hygiene and maintainability continue.
The usual round of bug fixes, compatibility changes, and incremental improvements.
(9.53.0) We have added the capability to build with the Tesseract OCR engine. In such a build, new devices are available (pdfocr8/pdfocr24/pdfocr32) which render the output file to an image, OCR that image, and output the image "wrapped" up as a PDF file, with the OCR generated text information included as "invisible" text (in PDF terms, text rendering mode 3).
Mainly due to time constraints, we only support including Tesseract from source included in our release packages, and not linking to Tesseract/Leptonica shared libraries. Whether we add this capability will be largely dependent on community demand for the feature.
See Enabling OCR for more details.
For a list of open issues, or to report problems, please visit bugs.ghostscript.com.
Included below are incompatible changes from recent releases (the specific release in question is listed in parentheses). We include these, for now, as we are aware that not everyone upgrades with every release.
(9.55.0) Changes to the
device API. This will affect developers and maintainers of Ghostscript devices. Firstly, and most importantly, the way device-specific "procs" are specified has been rewritten to make it (we think!) clearer and less confusing. See The Interface between Ghostscript and Device Drivers and The Great Device Rework Of 2021 for more details.
(9.55.0) The command line options
-dGraphicsKPreserve=#have been changed to
(9.53.0) As of 9.53.0, we have (re-)introduced the patch level to the version number, this helps facilitate a revised policy on handling security-related issues.
Note for GSView Users: The patch level addition breaks GSView 5 (it is hardcoded to check for versions
704-999. It is possible, but not guaranteed that a GSView update might be forthcoming to resolve this.
-dALLOWPSTRANSPARENCY: The transparency compositor (and related features), whilst we are improving it, remains sensitive to being driven correctly, and incorrect use can have unexpected/undefined results. Hence, as part of improving security, we limited access to these operators, originally using the
-dSAFERfeature. As we made "SAFER" the default mode, that became unacceptable, hence the new option
-dALLOWPSTRANSPARENCYwhich enables access to the operators.
(9.50) There are a couple of subtle incompatibilities between the old and new SAFER implementations. Firstly, as mentioned in the 9.50 release notes, SAFER now leaves standard PostScript functionality unchanged (except for the file access limitations). Secondly, the interaction with
restoreoperations has changed. See SAFER.
Important Note for Windows Users:
The file/path pattern matching is case-sensitive, even on Windows. This is a change in behaviour compared to the old code which, on Windows, was case insensitive. This is in recognition of changes in Windows behaviour, in that it now supports (although does not enforce) case sensitivity.
(9.27) The process of "tidying" the PostScript namespace should have removed only non-standard and undocumented operators. Nevertheless, it is possible that any integrations or utilities that rely on those non-standard and undocumented operators may stop working or may change behaviour.
If you encounter such a case, please contact us (Discord, #ghostscript IRC channel, or the gs-devel mailing list would be best), and we'll work with you to either find an alternative solution or return the previous functionality, if there is genuinely no other option.
From 9.55.0 onwards, in recognition of how unwieldy very large HTML files can become (History9.html had reached 8.1Mb!), we intend to only include the summary highlights (above).
For anyone wanting the full details of the changes in a release, we ask them to look at the history in our public git repository: ghostpdl-10.00.0 log.
If this change does not draw negative feedback, History?.htm file(s) will be removed from the release archives.
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This software is provided AS-IS with no warranty, either express or implied. This software is distributed under license and may not be copied, modified or distributed except as expressly authorized under the terms of that license. Refer to licensing information at https://www.artifex.com or contact Artifex Software, Inc., 1305 Grant Avenue - Suite 200, Novato, CA 94945, U.S.A., +1(415)492-9861, for further information.
Ghostscript version 10.00.0, 17 August 2022