poppler-agg is meant to provide an AGG (http://antigrain.com) rendering back-end to the poppler (http://poppler.freedesktop.org/) library.
The git repository contains two branches. (a) "master" which is a clone of the official poppler repo and (b) "agg_support" which I use to add everything for (you guessed it) AGG support.
AGG the Anti-Grain Geometry Library represents a somewhat obscure software project. Although one might say that it is currently unmaintained it still provides a hi-quality graphics engine well comparable with projects like cairo. AGG makes heavy use of C++ templates which constitutes a major advantage as well as a potential drawback.
On the one hand, all aspects of the underling color space and color storage model can be manipulated via template arguments, making it possibly to provide a large set of output formats for specialized hardware like printers with very specific needs for custom color spaces and bit-depth per channel. Furthermore there are no hardware dependent parts in the AGG library. It simply operates on abstracted two dimensional arrays of pixels.
On the other hand the heavy use of templated classes might make it complicated to create speed optimized hardware specific code. One may not expect performance wonders when using an AGG back-end.
The poppler-agg relies on my variant of the agg code to be found under
https://github.com/oncaphillis/agg
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The AGG backend currently supports three color spaces "rgba" and "cmyka" "device_na". The is still ecperimenta and meant to mirror the DeviceN colorspace of PDF.
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All Vector graphics shound work. All amjor line drawings and fill operations should workd. Although more exotic fill types are still missing.
The next thing on my mind is Text drawing.
First you will have to install a modified version of AGG which can be found under (https://github.com/oncaphillis/agg.git). This variant supports the agg::cmyka color space and the agg::pixfmt_cmyk storage model.
After this you will have to switch into the "agg_support" branch of the poppler-agg checkout and configure the package with the --with-agg argument. The headers and libs of the modified agg installation should be made available via the CXXFLAGS and LDFLAGS environment variables like:
LDFLAGS="-L/path/to/agg/libs/" CXXFLAGS="-I/path/to/agg/headers" ./configure --with-agg
Install the poppler library as usual. In addition to the the standard poppler utils you will find the "pdftoagg" program.
Invoking
pdftoagg [-cmyk|-rgb] [file.pdf]
Will create "file.tif" from "file.pdf" representing the first page of the pdf document (at least the vector graphics part). The internal color model will be cmyk or rgb depending on the give flag. Under standard configuration the resulting "file.tif" will always be RGB. CMYK colors will be transformed befor saving. If compilation is done with the SPLASH_CMYK=1 macro defined the program will output a CMYK tif file.
Sebastian Kloska (oncaphillis@snafu.de)
This is poppler, a PDF rendering library.
Poppler is a fork of the xpdf PDF viewer developed by Derek Noonburg of Glyph and Cog, LLC. The purpose of forking xpdf is twofold. First, we want to provide PDF rendering functionality as a shared library, to centralize the maintenance effort. Today a number of applications incorporate the xpdf code base, and whenever a security issue is discovered, all these applications exchange patches and put out new releases. In turn, all distributions must package and release new version of these xpdf based viewers. It's safe to say that there's a lot of duplicated effort with the current situation. Even if poppler in the short term introduces yet another xpdf derived code base to the world, we hope that over time these applications will adopt poppler. After all, we only need one application to use poppler to break even.
Second, we would like to move libpoppler forward in a number of areas that don't fit within the goals of xpdf. By design, xpdf depends on very few libraries and runs a wide range of X based platforms. This is a strong feature and reasonable design goal. However, with poppler we would like to replace parts of xpdf that are now available as standard components of modern Unix desktop environments. One such example is fontconfig, which solves the problem of matching and locating fonts on the system, in a standardized and well understood way. Another example is cairo, which provides high quality 2D rendering. See the file TODO for a list of planned changes.
Please note that xpdf, and thus poppler, is licensed under the GPL, not the LGPL. Consequently, any application using poppler must also be licensed under the GPL. If you want to incorporate Xpdf based PDF rendering in a closed source product, please contact Glyph & Cog (www.glyphandcog.com) for commercial licensing options.
Kristian Høgsberg, Feb. 27, 2005
See the README-XPDF for the original xpdf-3.03 README.