+2013-10-27 Xue Fuqiao <xfq.free@gmail.com>
+
+ * display.texi (Image Descriptors): Add an index for edge-detection algorithms.
+
2013-10-26 Xue Fuqiao <xfq.free@gmail.com>
* display.texi (Fringe Indicators): Add indexes for fringe indicators.
@table @asis
@item @code{(+ @var{n})}
+@c FIXME: Add an index for "step"? --xfq
This means to use a font that is @var{n} steps larger. A ``step'' is
defined by the set of available fonts---specifically, those that match
what was otherwise specified for this text, in all attributes except
``disabled'' button.
@item (edge-detection :matrix @var{matrix} :color-adjust @var{adjust})
+@cindex edge detection, images
Specifies a general edge-detection algorithm. @var{matrix} must be
either a nine-element list or a nine-element vector of numbers. A pixel
at position @math{x/y} in the transformed image is computed from