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svn+ssh://pythondev@svn.python.org/python/trunk ........ r68133 | antoine.pitrou | 2009-01-01 16:38:03 +0100 (Thu, 01 Jan 2009) | 1 line fill in actual issue number in tests ........ r68134 | hirokazu.yamamoto | 2009-01-01 16:45:39 +0100 (Thu, 01 Jan 2009) | 2 lines Issue #4797: IOError.filename was not set when _fileio.FileIO failed to open file with `str' filename on Windows. ........ r68141 | benjamin.peterson | 2009-01-01 17:43:12 +0100 (Thu, 01 Jan 2009) | 1 line fix highlighting ........ r68142 | benjamin.peterson | 2009-01-01 18:29:49 +0100 (Thu, 01 Jan 2009) | 2 lines welcome to 2009, Python! ........ r68145 | amaury.forgeotdarc | 2009-01-02 01:03:54 +0100 (Fri, 02 Jan 2009) | 5 lines #4801 _collections module fails to build on cygwin. _PyObject_GC_TRACK is the macro version of PyObject_GC_Track, and according to documentation it should not be used for extension modules. ........ r68146 | ronald.oussoren | 2009-01-02 11:44:46 +0100 (Fri, 02 Jan 2009) | 2 lines Fix for issue4472: "configure --enable-shared doesn't work on OSX" ........ r68148 | ronald.oussoren | 2009-01-02 11:48:31 +0100 (Fri, 02 Jan 2009) | 2 lines Forgot to add a NEWS item in my previous checkin ........ r68149 | ronald.oussoren | 2009-01-02 11:50:48 +0100 (Fri, 02 Jan 2009) | 2 lines Fix for issue4780 ........ r68159 | ronald.oussoren | 2009-01-02 15:48:17 +0100 (Fri, 02 Jan 2009) | 2 lines Fix for issue 1627952 ........ r68160 | ronald.oussoren | 2009-01-02 15:52:09 +0100 (Fri, 02 Jan 2009) | 2 lines Fix for issue r1737832 ........ r68161 | ronald.oussoren | 2009-01-02 16:00:05 +0100 (Fri, 02 Jan 2009) | 3 lines Fix for issue 1149804 ........ r68162 | ronald.oussoren | 2009-01-02 16:06:00 +0100 (Fri, 02 Jan 2009) | 3 lines Fix for issue 4472 is incompatible with Cygwin, this patch should fix that. ........ r68166 | benjamin.peterson | 2009-01-02 19:26:23 +0100 (Fri, 02 Jan 2009) | 1 line document PyMemberDef ........ r68171 | georg.brandl | 2009-01-02 21:25:14 +0100 (Fri, 02 Jan 2009) | 3 lines #4811: fix markup glitches (mostly remains of the conversion), found by Gabriel Genellina. ........ r68172 | martin.v.loewis | 2009-01-02 21:32:55 +0100 (Fri, 02 Jan 2009) | 2 lines Issue #4075: Use OutputDebugStringW in Py_FatalError. ........ r68173 | martin.v.loewis | 2009-01-02 21:40:14 +0100 (Fri, 02 Jan 2009) | 2 lines Issue #4051: Prevent conflict of UNICODE macros in cPickle. ........ r68174 | benjamin.peterson | 2009-01-02 21:47:27 +0100 (Fri, 02 Jan 2009) | 1 line fix compilation on non-Windows platforms ........ r68179 | raymond.hettinger | 2009-01-02 22:26:45 +0100 (Fri, 02 Jan 2009) | 1 line Issue #4615. Document how to use itertools for de-duping. ........ r68195 | georg.brandl | 2009-01-03 14:45:15 +0100 (Sat, 03 Jan 2009) | 2 lines Remove useless string literal. ........ r68196 | georg.brandl | 2009-01-03 15:29:53 +0100 (Sat, 03 Jan 2009) | 2 lines Fix indentation. ........ r68210 | georg.brandl | 2009-01-03 20:10:12 +0100 (Sat, 03 Jan 2009) | 2 lines Set eol-style correctly for mp_distributing.py. ........ r68214 | georg.brandl | 2009-01-03 20:44:48 +0100 (Sat, 03 Jan 2009) | 2 lines Make indentation consistent. ........ r68215 | georg.brandl | 2009-01-03 21:15:14 +0100 (Sat, 03 Jan 2009) | 2 lines Fix role name. ........ r68217 | georg.brandl | 2009-01-03 21:30:15 +0100 (Sat, 03 Jan 2009) | 2 lines Add rstlint, a little tool to find subtle markup problems and inconsistencies in the Doc sources. ........ r68218 | georg.brandl | 2009-01-03 21:38:59 +0100 (Sat, 03 Jan 2009) | 2 lines Recognize usage of the default role. ........ r68219 | georg.brandl | 2009-01-03 21:47:01 +0100 (Sat, 03 Jan 2009) | 2 lines Fix uses of the default role. ........ r68220 | georg.brandl | 2009-01-03 21:55:06 +0100 (Sat, 03 Jan 2009) | 2 lines Remove trailing whitespace. ........ r68221 | georg.brandl | 2009-01-03 22:04:55 +0100 (Sat, 03 Jan 2009) | 2 lines Remove tabs from the documentation. ........ r68222 | georg.brandl | 2009-01-03 22:11:58 +0100 (Sat, 03 Jan 2009) | 2 lines Disable the line length checker by default. ........
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3.8 KiB
ReStructuredText
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ReStructuredText
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:mod:`jpeg` --- Read and write JPEG files
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=========================================
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.. module:: jpeg
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:platform: IRIX
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:synopsis: Read and write image files in compressed JPEG format.
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:deprecated:
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.. deprecated:: 2.6
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The :mod:`jpeg` module has been deprecated for removal in Python 3.0.
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.. index:: single: Independent JPEG Group
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The module :mod:`jpeg` provides access to the jpeg compressor and decompressor
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written by the Independent JPEG Group (IJG). JPEG is a standard for compressing
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pictures; it is defined in ISO 10918. For details on JPEG or the Independent
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JPEG Group software refer to the JPEG standard or the documentation provided
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with the software.
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.. index::
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single: Python Imaging Library
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single: PIL (the Python Imaging Library)
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single: Lundh, Fredrik
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A portable interface to JPEG image files is available with the Python Imaging
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Library (PIL) by Fredrik Lundh. Information on PIL is available at
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http://www.pythonware.com/products/pil/.
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The :mod:`jpeg` module defines an exception and some functions.
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.. exception:: error
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Exception raised by :func:`compress` and :func:`decompress` in case of errors.
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.. function:: compress(data, w, h, b)
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.. index:: single: JFIF
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Treat data as a pixmap of width *w* and height *h*, with *b* bytes per pixel.
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The data is in SGI GL order, so the first pixel is in the lower-left corner.
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This means that :func:`gl.lrectread` return data can immediately be passed to
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:func:`compress`. Currently only 1 byte and 4 byte pixels are allowed, the
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former being treated as greyscale and the latter as RGB color. :func:`compress`
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returns a string that contains the compressed picture, in JFIF format.
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.. function:: decompress(data)
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.. index:: single: JFIF
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Data is a string containing a picture in JFIF format. It returns a tuple
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``(data, width, height, bytesperpixel)``. Again, the data is suitable to pass
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to :func:`gl.lrectwrite`.
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.. function:: setoption(name, value)
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Set various options. Subsequent :func:`compress` and :func:`decompress` calls
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will use these options. The following options are available:
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+-----------------+---------------------------------------------+
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| Option | Effect |
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+=================+=============================================+
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| ``'forcegray'`` | Force output to be grayscale, even if input |
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| | is RGB. |
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+-----------------+---------------------------------------------+
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| ``'quality'`` | Set the quality of the compressed image to |
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| | a value between ``0`` and ``100`` (default |
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| | is ``75``). This only affects compression. |
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+-----------------+---------------------------------------------+
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| ``'optimize'`` | Perform Huffman table optimization. Takes |
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| | longer, but results in smaller compressed |
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| | image. This only affects compression. |
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+-----------------+---------------------------------------------+
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| ``'smooth'`` | Perform inter-block smoothing on |
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| | uncompressed image. Only useful for low- |
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| | quality images. This only affects |
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| | decompression. |
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+-----------------+---------------------------------------------+
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.. seealso::
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JPEG Still Image Data Compression Standard
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The canonical reference for the JPEG image format, by Pennebaker and Mitchell.
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`Information Technology - Digital Compression and Coding of Continuous-tone Still Images - Requirements and Guidelines <http://www.w3.org/Graphics/JPEG/itu-t81.pdf>`_
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The ISO standard for JPEG is also published as ITU T.81. This is available
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online in PDF form.
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