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Diffstat (limited to 'Doc/lib/libjpeg.tex')
| -rw-r--r-- | Doc/lib/libjpeg.tex | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/Doc/lib/libjpeg.tex b/Doc/lib/libjpeg.tex index a4e931f..b5c14a4 100644 --- a/Doc/lib/libjpeg.tex +++ b/Doc/lib/libjpeg.tex @@ -1,19 +1,19 @@ \section{Built-in Module \sectcode{jpeg}} \bimodindex{jpeg} -The module jpeg provides access to the jpeg compressor and -decompressor written by the Independent JPEG Group. JPEG is a (draft?) +The module \code{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 jpeg module defines these functions: +The \code{jpeg} module defines these functions: \renewcommand{\indexsubitem}{(in module jpeg)} \begin{funcdesc}{compress}{data\, w\, h\, b} -Treat data as a pixmap of width w and height h, with b bytes per +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 lrectread return data can +lower-left corner. This means that \code{lrectread} return data can immedeately 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 @@ -24,28 +24,28 @@ compressed picture, in JFIF format. 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 lrectwrite. +Again, the data is suitable to pass to \code{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'}] +\item[\code{'forcegray' }] Force output to be grayscale, even if input is RGB. -\item[\code{'quality'}] +\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'}] +\item[\code{'optimize' }] Perform Huffman table optimization. Takes longer, but results in smaller compressed image. Compress only. -\item[\code{'smooth'}] +\item[\code{'smooth' }] Perform inter-block smoothing on uncompressed image. Only useful for low-quality images. Decompress only. \end{description} \end{funcdesc} -Compress and uncompress raise the error jpeg.error in case of errors. +Compress and uncompress raise the error \code{jpeg.error} in case of errors. |