impad

% -*- texinfo -*-
% @deftypefn {Function File} {} impad(@var{A}, @var{xpad}, @var{ypad}, [@var{padding}, [@var{const}]])
% Pad (augment) a matrix for application of image processing algorithms.
%
% Pads the input image @var{A} with @var{xpad}(1) elements from left, 
% @var{xpad}(2), elements from right, @var{ypad}(1) elements from above 
% and @var{ypad}(2) elements from below.
% Values of padding elements are determined from the optional arguments
% @var{padding} and @var{const}. @var{padding} is one of
%
% @table @samp
% @item 'zeros'     
% pad with zeros (default)
%
% @item 'ones'      
% pad with ones
%
% @item 'constant'  
% pad with a value obtained from the optional fifth argument const
%
% @item 'symmetric' 
% pad with values obtained from @var{A} so that the padded image mirrors 
% @var{A} starting from edges of @var{A}
% 
% @item 'reflect'   
% same as symmetric, but the edge rows and columns are not used in the padding
%
% @item 'replicate' 
% pad with values obtained from A so that the padded image 
% repeates itself in two dimensions
% 
% @end table
% @end deftypefn