% for NEGATIVE PRINT OF IMAGE; often saves toner.            Steve Mann; 1990OCT22
%
% LOG SCALED
%
% scales a real matrix to [0,255] range, takes 255-image,
% and places a border of all black (zeros) around the outside.
% the dimension is increased by 2 (or more) each way
%
% Y = border(X);       % black border all around
%                      % so if image is mostly white, you can see its region of support
%
% Y = border(X,2);     % double thickness border all around
%
% Y = border(X,3,4);   % 3 rows of zeros, 4 cols of zeros;
%                      % looks nice on a 3by4 image (eg. TV screen size)

function Y = dummy(X,thicknessrow,thicknesscol)

minX = min(min(X));
thresh = input(sprintf('smallest image value = %g; choose thres to avoid neg. val.s; big thresh==flat hist ',minX));

if nargin == 2
  thicknesscol = thicknessrow;
end%if
if nargin == 1
  thicknesscol = 1;
  thicknessrow = 1;
end%if

[M N] = size(X);
rowpad = zeros(thicknessrow,N);
colpad = zeros(M+2*thicknessrow,thicknesscol);

Y = [colpad [rowpad;255-scaler2(log(X+thresh));rowpad] colpad];

dis = sprintf('   to   %g by %g,   took NEGATIVE and SCALED to [0,255] range',M+2*thicknessrow,N+2*thicknesscol);
disp([sprintf('zero padded   %g by %g',M,N) dis])