13.11 Inserting Images
======================


You can insert an image given in an external file with the
@image command:

@image{filename, [width], [height], [alttext], [extension]}

The filename argument is mandatory, and must not have an
extension, because the different processors support different formats:
* TeX reads the file `filename.eps' (Encapsulated PostScript
format).
* PDFTeX reads `filename.pdf' (Adobe's Portable Document Format).
* makeinfo uses `filename.txt' verbatim for
Info output (more or less as if it was an @example).
* makeinfo
uses the optional fifth argument to @image for the extension if
you supply it.  For example:

@image{foo,,,,xpm}

will cause `makeinfo --html' to try `foo.xpm'.

If you do not supply the optional fifth argument, `makeinfo
---html' first tries `filename.png'; if that does not exist,
it tries `filename.jpg'.  If that does not exist either, it
complains.  (We cannot support GIF format directly due to software
patents.)

The optional width and height arguments specify the size to
scale the image to (they are ignored for Info output).  If neither is
specified, the image is presented in its natural size (given in the
file); if only one is specified, the other is scaled proportionately;
and if both are specified, both are respected, thus possibly distorting
the original image by changing its aspect ratio.

The width and height may be specified using any valid TeX
dimension, namely:

pt
point (72.27pt = 1in)
pc
pica (1pc = 12pt)
bp
big point (72bp = 1in)
in
inch
cm
centimeter (2.54cm = 1in)
mm
millimeter (10mm = 1cm)
dd
dido^t point (1157dd = 1238pt)
cc
cicero (1cc = 12dd)
sp
scaled point (65536sp = 1pt)

For example, the following will scale a file `ridt.eps' to one
inch vertically, with the width scaled proportionately:

@image{ridt,,1in}

For @image to work with TeX, the file `epsf.tex' must be
installed somewhere that TeX can find it.  (The standard location is
`texmf/tex/generic/dvips/epsf.tex', where texmf is a
root of your TeX directory tree.)  This file is included in the
Texinfo distribution and is also available from
<ftp://tug.org/tex/epsf.tex>, among other places.

@image can be used within a line as well as for displayed
figures.  Therefore, if you intend it to be displayed, be sure to leave
a blank line before the command, or the output will run into the
preceding text.

When producing html, makeinfo sets the alt attribute for
inline images to the optional fourth argument to @image, if
supplied.  If not supplied, makeinfo uses the full file name of
the image being displayed.


