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diff --git a/Doc/lib/libjpeg.tex b/Doc/lib/libjpeg.tex deleted file mode 100644 index a10e06c..0000000 --- a/Doc/lib/libjpeg.tex +++ /dev/null @@ -1,80 +0,0 @@ -\section{\module{jpeg} --- - Read and write JPEG files} - -\declaremodule{builtin}{jpeg} - \platform{IRIX} -\modulesynopsis{Read and write image files in compressed JPEG format.} - - -The module \module{jpeg} provides access to the jpeg compressor and -decompressor written by the Independent JPEG Group -\index{Independent JPEG Group}(IJG). JPEG is a standard for -compressing pictures; it is defined in ISO 10918. For details on JPEG -or the Independent JPEG Group software refer to the JPEG standard or -the documentation provided with the software. - -A portable interface to JPEG image files is available with the Python -Imaging Library (PIL) by Fredrik Lundh. Information on PIL is -available at \url{http://www.pythonware.com/products/pil/}. -\index{Python Imaging Library} -\index{PIL (the Python Imaging Library)} -\index{Lundh, Fredrik} - -The \module{jpeg} module defines an exception and some functions. - -\begin{excdesc}{error} -Exception raised by \function{compress()} and \function{decompress()} -in case of errors. -\end{excdesc} - -\begin{funcdesc}{compress}{data, w, h, b} -Treat data as a pixmap of width \var{w} and height \var{h}, with -\var{b} bytes per pixel. The data is in SGI GL order, so the first -pixel is in the lower-left corner. This means that \function{gl.lrectread()} -return data can immediately be passed to \function{compress()}. -Currently only 1 byte and 4 byte pixels are allowed, the former being -treated as greyscale and the latter as RGB color. -\function{compress()} returns a string that contains the compressed -picture, in JFIF\index{JFIF} format. -\end{funcdesc} - -\begin{funcdesc}{decompress}{data} -Data is a string containing a picture in JFIF\index{JFIF} format. It -returns a tuple \code{(\var{data}, \var{width}, \var{height}, -\var{bytesperpixel})}. Again, the data is suitable to pass to -\function{gl.lrectwrite()}. -\end{funcdesc} - -\begin{funcdesc}{setoption}{name, value} -Set various options. Subsequent \function{compress()} and -\function{decompress()} calls will use these options. The following -options are available: - -\begin{tableii}{l|p{3in}}{code}{Option}{Effect} - \lineii{'forcegray'}{% - Force output to be grayscale, even if input is RGB.} - \lineii{'quality'}{% - Set the quality of the compressed image to a value between - \code{0} and \code{100} (default is \code{75}). This only affects - compression.} - \lineii{'optimize'}{% - Perform Huffman table optimization. Takes longer, but results in - smaller compressed image. This only affects compression.} - \lineii{'smooth'}{% - Perform inter-block smoothing on uncompressed image. Only useful - for low-quality images. This only affects decompression.} -\end{tableii} -\end{funcdesc} - - -\begin{seealso} - \seetitle{JPEG Still Image Data Compression Standard}{The - canonical reference for the JPEG image format, by - Pennebaker and Mitchell.} - - \seetitle[http://www.w3.org/Graphics/JPEG/itu-t81.pdf]{Information - Technology - Digital Compression and Coding of - Continuous-tone Still Images - Requirements and - Guidelines}{The ISO standard for JPEG is also published as - ITU T.81. This is available online in PDF form.} -\end{seealso} |