PaletteOptimiser

Annotated README.txt

98:e4db053e9a3b
2015-10-10 Paul Boddie Added tag snapshot-20151010 for changeset cd6bc22cd40b simpleimage-shedskin
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Introduction
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============
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PaletteOptimiser is a tool for converting images to the eight colours
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supported on the 8-bit Acorn microcomputers: black, white, and the primary and
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secondary colours. It then chooses four of these colours per horizontal line
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of each eight-colour image, permitting such images to be displayed in
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four-colour modes with palette switching on a line-by-line basis.
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Usage
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=====
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optimiser.py <input filename> <output filename> [ <options> ]
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Run the program with the --help argument to see a description of the options:
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optimiser.py --help
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Dependencies
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============
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Apart from Python, this software requires the following:
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Packages                    Release Information
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--------                    -------------------
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Python Imaging Library      Debian package: python-imaging
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(PIL)                       (Tested with 1.1.7-4+deb7u1)
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                            Source: http://www.effbot.org/zone/pil-index.htm
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exif-py                     Debian package: python-exif
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                            (Tested with 1.0.8-3)
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                            Source: https://github.com/ianare/exif-py
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The following optional dependencies apply for compilation with Shedskin:
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Packages                    Release Information
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--------                    -------------------
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Shedskin                    Debian package: shedskin
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                            (Tested with 0.9.2-2)
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                            Source: http://code.google.com/p/shedskin/
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g++                         Debian package: g++
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                            (Tested with 4:4.7.2-1)
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                            Source: https://gcc.gnu.org/
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make                        Debian package: make
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                            (Tested with 3.81-8.2)
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                            Source: https://www.gnu.org/software/make/
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Compilation with Shedskin
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=========================
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Suitable versions of the code (see the simpleimage-shedskin branch below) can
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be compiled with the Shedskin Python-to-C++ compiler for additional
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performance gains. This is done as follows:
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shedskin -e optimiserlib.py
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make
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A file called optimiserlib.so should be produced which should then behave just
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like the original Python version, at least when used with the optimiser.py
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program.
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Repository Branches
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===================
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The default branch is the original development branch where new techniques
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have been introduced.
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The simpleimage branch introduces an alternative image class so that the image
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processing routines need not be tightly coupled with the Python Imaging
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Library abstractions.
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The simpleimage-shedskin branch takes advantage of the simpleimage branch to
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define a separate module that can be compiled using the Shedskin Python-to-C++
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compiler. The resulting compiled module enables an approximate four-fold
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increase in speed.
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The shedskin branch is an obsolete and not particularly effective attempt to
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try and get an earlier version of the tool to compile using Shedskin.
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Contact, Copyright and Licence Information
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==========================================
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See the following Web page for more information about this work:
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http://hgweb.boddie.org.uk/PaletteOptimiser
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The author can be contacted at the following e-mail address:
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paul@boddie.org.uk
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Copyright and licence information can be found in the docs directory - see
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docs/COPYING.txt and docs/gpl-3.0.txt for more information.