PaletteOptimiser

README.txt

103:2cc185ffe5fd
2015-10-11 Paul Boddie Added tag snapshot-20151011 for changeset 880ad0960d07 simpleimage-shedskin
     1 Introduction
     2 ============
     3 
     4 PaletteOptimiser is a tool for converting images to the eight colours
     5 supported on the 8-bit Acorn microcomputers: black, white, and the primary and
     6 secondary colours. It then chooses four of these colours per horizontal line
     7 of each eight-colour image, permitting such images to be displayed in
     8 four-colour modes with palette switching on a line-by-line basis.
     9 
    10 Usage
    11 =====
    12 
    13 optimiser.py <input filename> <output filename> [ <options> ]
    14 
    15 Run the program with the --help argument to see a description of the options:
    16 
    17 optimiser.py --help
    18 
    19 Dependencies
    20 ============
    21 
    22 Apart from Python, this software requires the following:
    23 
    24 Packages                    Release Information
    25 --------                    -------------------
    26 
    27 Python Imaging Library      Debian package: python-imaging
    28 (PIL)                       (Tested with 1.1.7-4+deb7u1)
    29                             Source: http://www.effbot.org/zone/pil-index.htm
    30 
    31 exif-py                     Debian package: python-exif
    32                             (Tested with 1.0.8-3)
    33                             Source: https://github.com/ianare/exif-py
    34 
    35 The following optional dependencies apply for compilation with Shedskin:
    36 
    37 Packages                    Release Information
    38 --------                    -------------------
    39 
    40 Shedskin                    Debian package: shedskin
    41                             (Tested with 0.9.2-2)
    42                             Source: http://code.google.com/p/shedskin/
    43 
    44 g++                         Debian package: g++
    45                             (Tested with 4:4.7.2-1)
    46                             Source: https://gcc.gnu.org/
    47 
    48 make                        Debian package: make
    49                             (Tested with 3.81-8.2)
    50                             Source: https://www.gnu.org/software/make/
    51 
    52 Compilation with Shedskin
    53 =========================
    54 
    55 Suitable versions of the code (see the simpleimage-shedskin branch below) can
    56 be compiled with the Shedskin Python-to-C++ compiler for additional
    57 performance gains. This is done as follows:
    58 
    59 shedskin -e optimiserlib.py
    60 make
    61 
    62 A file called optimiserlib.so should be produced which should then behave just
    63 like the original Python version, at least when used with the optimiser.py
    64 program.
    65 
    66 Repository Branches
    67 ===================
    68 
    69 The default branch is the original development branch where new techniques
    70 have been introduced.
    71 
    72 The simpleimage branch introduces an alternative image class so that the image
    73 processing routines need not be tightly coupled with the Python Imaging
    74 Library abstractions.
    75 
    76 The simpleimage-shedskin branch takes advantage of the simpleimage branch to
    77 define a separate module that can be compiled using the Shedskin Python-to-C++
    78 compiler. The resulting compiled module enables an approximate four-fold
    79 increase in speed.
    80 
    81 The shedskin branch is an obsolete and not particularly effective attempt to
    82 try and get an earlier version of the tool to compile using Shedskin.
    83 
    84 Contact, Copyright and Licence Information
    85 ==========================================
    86 
    87 See the following Web page for more information about this work:
    88 
    89 http://hgweb.boddie.org.uk/PaletteOptimiser
    90 
    91 The author can be contacted at the following e-mail address:
    92 
    93 paul@boddie.org.uk
    94 
    95 Copyright and licence information can be found in the docs directory - see
    96 docs/COPYING.txt and docs/gpl-3.0.txt for more information.