\label{module-jpeg}
\bimodindex{jpeg}
-The module \code{jpeg} provides access to the jpeg compressor and
-decompressor written by the Independent JPEG Group. JPEG is a (draft?)\
+The module \module{jpeg} provides access to the jpeg compressor and
+decompressor written by the Independent JPEG Group. JPEG is a (draft?)
standard for compressing pictures. For details on jpeg or the
Independent JPEG Group software refer to the JPEG standard or the
documentation provided with the software.
-The \code{jpeg} module defines these functions:
-
-\setindexsubitem{(in module jpeg)}
-\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 \code{lrectread} return data can
-immediately be passed to compress. Currently only 1 byte and 4 byte
-pixels are allowed, the former being treated as greyscale and the
-latter as RGB color. Compress returns a string that contains the
-compressed picture, in JFIF format.
+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 \code{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 format.
\end{funcdesc}
\begin{funcdesc}{decompress}{data}
Data is a string containing a picture in JFIF format. It returns a
-tuple
-\code{(\var{data}, \var{width}, \var{height}, \var{bytesperpixel})}.
-Again, the data is suitable to pass to \code{lrectwrite}.
+tuple \code{(\var{data}, \var{width}, \var{height},
+\var{bytesperpixel})}. Again, the data is suitable to pass to
+\code{gl.lrectwrite}.
\end{funcdesc}
-\begin{funcdesc}{setoption}{name\, value}
-Set various options. Subsequent compress and decompress calls
-will use these options. The following options are available:
-\begin{description}
-\item[\code{'forcegray' }]
-Force output to be grayscale, even if input is RGB.
-
-\item[\code{'quality' }]
-Set the quality of the compressed image to a
-value between \code{0} and \code{100} (default is \code{75}). Compress only.
-
-\item[\code{'optimize' }]
-Perform Huffman table optimization. Takes longer, but results in
-smaller compressed image. Compress only.
-
-\item[\code{'smooth' }]
-Perform inter-block smoothing on uncompressed image. Only useful for
-low-quality images. Decompress only.
-\end{description}
+\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|l|}{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}
-
-Compress and uncompress raise the error \code{jpeg.error} in case of errors.
\label{module-jpeg}
\bimodindex{jpeg}
-The module \code{jpeg} provides access to the jpeg compressor and
-decompressor written by the Independent JPEG Group. JPEG is a (draft?)\
+The module \module{jpeg} provides access to the jpeg compressor and
+decompressor written by the Independent JPEG Group. JPEG is a (draft?)
standard for compressing pictures. For details on jpeg or the
Independent JPEG Group software refer to the JPEG standard or the
documentation provided with the software.
-The \code{jpeg} module defines these functions:
-
-\setindexsubitem{(in module jpeg)}
-\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 \code{lrectread} return data can
-immediately be passed to compress. Currently only 1 byte and 4 byte
-pixels are allowed, the former being treated as greyscale and the
-latter as RGB color. Compress returns a string that contains the
-compressed picture, in JFIF format.
+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 \code{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 format.
\end{funcdesc}
\begin{funcdesc}{decompress}{data}
Data is a string containing a picture in JFIF format. It returns a
-tuple
-\code{(\var{data}, \var{width}, \var{height}, \var{bytesperpixel})}.
-Again, the data is suitable to pass to \code{lrectwrite}.
+tuple \code{(\var{data}, \var{width}, \var{height},
+\var{bytesperpixel})}. Again, the data is suitable to pass to
+\code{gl.lrectwrite}.
\end{funcdesc}
-\begin{funcdesc}{setoption}{name\, value}
-Set various options. Subsequent compress and decompress calls
-will use these options. The following options are available:
-\begin{description}
-\item[\code{'forcegray' }]
-Force output to be grayscale, even if input is RGB.
-
-\item[\code{'quality' }]
-Set the quality of the compressed image to a
-value between \code{0} and \code{100} (default is \code{75}). Compress only.
-
-\item[\code{'optimize' }]
-Perform Huffman table optimization. Takes longer, but results in
-smaller compressed image. Compress only.
-
-\item[\code{'smooth' }]
-Perform inter-block smoothing on uncompressed image. Only useful for
-low-quality images. Decompress only.
-\end{description}
+\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|l|}{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}
-
-Compress and uncompress raise the error \code{jpeg.error} in case of errors.
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