Software Update: Ghostscript 9.02

Version 9.02 of Ghostscript has been released, the second update for last September released version 9. Ghostscript is an open source interpreter for the Adobe-developed markup language PostScript, a programming language for describing a set of text and images in a device-independent way. In this way, a PostScript file should in principle be printed the same by every laser printer. Since version 9, a icc-definition for color formatting and of freetype for handling fonts. The main changes since version 9.00 are summarized below.

Version 9.02

• This is an “out of order” release, primarily to ensure the GPL Ghostscript release remains in version “lock-step” with the Artifex commercial release.
• For monochrome devices, there is a new halftone technique for sampled image data. The existing technique is very efficient (and is still used) for large areas of color, such as an area fill, but encountered performance problems dealing with sampled image data where a given color value only covered a few pixels at a time. The new approach applies the halftone threshold array directly to the image samples.
• Further performance, memory use, and stability improvements with the new features introduced in 9.00, as well as Unix/Linux build fixes, plus the usual assorted bug fixes.

Version 9.01

• A new, robust CFF parser implemented in C (replacing the previous Poscript one),
• tiffscaled device – this renders internally as tiffgray, but then downsamples by an integer scale factor (specified by -dDownScaleFactor=n) and error diffuses to 1bpp output. The tiffscaled device also implements limited minimum feature size functionality; by setting -dMinFeatureSize to 1, 2 or 3, the device output is guaranteed to generate minimum dot sizes as multiples of the final resolution, useful for devices that offer finer position control than dot size control.
• Add DSC compatible output in ps2write.
• Windows makefiles now support 64 bit builds on 64 bit systems.
• A number of performance, memory use, and stability improvements with the new features introduced in 9.00, plus the usual bug fixes.
• We have also dropped support for Watcom and Borland development environments. These had not been maintained for some time, and were suffering “bit rot”.

Version 9.00

• This release includes a move to an ICC-based color rendering workflow. The design allows easy integration of 3rd party color management modules (CMMs) and management of DeviceN and spot source colors with ICC profiles as well as with non-ICC proprietary methods. The default CMM is the well known littleCMS. Postscript color objects and non-ICC CIE-based PDF color spaces are converted to equivalent ICC profiles enabling complete color management for all color spaces by an ICC-based CMM. New command line options enable the specification of gray, rgb and cmyk default ICC profiles as well as output device ICC profiles. The new work flow provides performance improvements in the rendering of images, shadings and transparencies. In addition, the color conversions are designed to work efficiently in multithreaded display list (c-list) rendering through the use of a shared link cache. Finally, proper ICC based rendering now occurs for ALL XPS objects including Named colors, N-Channel colors and images with internally embedded ICC profiles.
• The second major change in this release is that glyph rendering for all font types except Type 3 is now handled by Freetype (via a much improved and enhanced Font API). The most obvious benefit of this is a complete, and proven implementation of the TrueType byte code interpreter (now unencumbered by patents).
• Another major change is that the Postscript interpreter’s graphics state now stores two separate color space settings for stroking and filling, to better support the stroke and fill colors required by the PDF interpreter.
• Finally, support for optional content has been added to the PDF interpreter.
• This release also includes a number of improvements to the pdfwrite device to improve reliability and quality with PCL and XPS input. Many improvements to the support of JPX images in PDF files, PDF annotation rendering and the usual number of general bug and robustness fixes.
• For security reasons, Ghostscript no longer searches the current directory by default. Use -P option to revert to old behavior.