docs for im_gradcor

man/Makefile.am

@@ -206,7 +206,10 @@ man_MANS = \
 	im_glds_mean.3 \
 	im_global_balance.3 \
 	im_global_balance_float.3 \
+	im_gradcor.3 \
 	im_gradient.3 \
+	im_grad_x.3 \
+	im_grad_y.3 \
 	im_grey.3 \
 	im_grid.3 \
 	im_guess_prefix.3 \

man/im_grad_x.3

@@ -0,0 +1,29 @@
+.TH IM_GRAD_X 3 "08 January 2008"
+.SH NAME
+ im_grad_x, im_grad_y \- find horizontal or vertical differences
+.SH SYNOPSIS
+.nf
+.B #include <vips/vips.h>
+.sp
+.BI "int im_grad_x( IMAGE " "*in" ", IMAGE " "*out" " );
+.br
+
+.BI "int im_grad_y( IMAGE " "*in" ", IMAGE " "*out" " );
+.fi
+.SH DESCRIPTION
+.B im_grad_x(3)
+generates an image where the value of each pixel is the difference between horizontally ajacent pixels in the input
+image.  The output has the same height as the input and one pixel less width.
+.PP 
+.B im_grad_y(3)
+generates an image where the value of each pixel is the difference between vertically ajacent pixels in the input
+image.  The output has the same width as the input and one pixel less height.
+.PP 
+In both cases, the input can be any uncoded integer type, and the output is signed 32 bit integer.
+.SH RETURN VALUE
+The functions returns 0 on success and -1 on error.
+.SH COPYRIGHT
+.br
+Copyright 2008, Nottingham Trent University.
+.SH AUTHOR
+Tom Vajzovic

man/im_grad_y.3

@@ -0,0 +1 @@
+.so man3/im_grad_x.3

man/im_gradcor.3

@@ -0,0 +1 @@
+.so man3/im_fastcor.3