%IM_BOX Fixed mapping determining a rectangular enclosing a blob (0/1 image)
%
% B = IM_BOX(A)
% B = A*IM_BOX
%
% If A is a 0/1 image then B is the same image with all empty (0) border
% columns and rows removed.
%
% B = IM_BOX(A,N)
%
% If A is a 0/1 image then B is the same image, but having in each direction
% N empty (0) columns and rows around the object (1).
%
% B = IM_BOX(A,[NX1 NX2 NY1 NY2])
%
% If A is a 0/1 image then B is the same image, but having NX1, NX2 empty
% columns (0) left, respectively right of the object (1) and NY1, NY2 empty
% rows (0) above, respectively below the object(1).
%
% B = IM_BOX(A,N,ALF)
%
% Adds as many empty (0) columns or rows such that the aspect ratio of
% images (height/width) equals ALF. For ALF == 1, square images are returned.
% For ALF == 0, images are taken as they are and N rows and columns are
% added.
%
% EXAMPLE
% prdatafiles; % make sure prdatafiles is in the path
% x = kimia_images; % load kimia images
% x = x*im_box(0); % remove all empty rows and columns
% x = x*im_box(0,1); % add rows/columns to make images square
% x = x*im_resize([32 32]); % resample them
% x = x*im_box(1,0); % add rows/columns and keep image square
% % now all images are 34x34 and no object touches the border.
% show(gendat(x,4)) % show a few
%
% SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>)
% DATASETS, DATAFILES
% Copyright: R.P.W. Duin, r.p.w.duin@37steps.com
% Faculty EWI, Delft University of Technology
% P.O. Box 5031, 2600 GA Delft, The Netherlands
function [b,J] = im_box(varargin)
argin = shiftargin(varargin,'vector');
argin = setdefaults(argin,[],[],[]);
if mapping_task(argin,'definition')
b = define_mapping(argin,'fixed');
b = setname(b,'Image bounding box');
else
[a,n,alf] = deal(argin{:});
if isdataset(a)
error('Command cannot be used for datasets as it may change image size')
elseif isdatafile(a)
isobjim(a);
b = filtim(a,mfilename,{n,alf});
%b = setfeatsize(b,getfeatsize(a));
elseif isa(a,'double') || isa(a,'dip_image') % here we have a single image
if isa(a,'dip_image'), a = double(a); end
if isempty(n)
jx = find(sum(a,1) ~= 0);
jy = find(sum(a,2) ~= 0);
J = [min(jy),max(jy),min(jx),max(jx)];
b = a(min(jy):max(jy),min(jx):max(jx));
else
if (~isempty(alf) && alf == 0)
c = a;
else
c = feval(mfilename,a);
end
[my,mx] = size(c);
if length(n) == 1
n = [n n n n];
elseif length(n) ~= 4
error('Second parameter should be scalar or vector of length 4')
end
b = zeros(my+n(3)+n(4),mx+n(1)+n(2));
b(n(3)+1:n(3)+my,n(1)+1:n(1)+mx) = c;
end
if ~isempty(alf) && alf ~= 0
[m,k] = size(b);
r = round(m*alf) - k;
if r == 0
;
elseif r >= 1 % add r columns
c = zeros(m,k+r);
c(:,ceil(r/2):ceil(r/2)+k-1) = b;
b = c;
else % add rows
r = round(k/alf) - m;
c = zeros(m+r,k);
c(ceil(r/2):ceil(r/2)+m-1,:) = b;
b = c;
end
end
end
end
return