source: prextra/impaint.m @ 5

function out = impaint(fig,varargin)
% out = impaint(fig)
%
% Create an overlay on the current active image and allow for painting the
% overlay.
% Possible calls:
%   impaint(h,'on');               start the overlay
%   impaint(h,'off');              remove the whole overlay
%   impaint(h,classnr,[r g b]);    define a new class with colour [r g b]
% out = impaint(h,'get');          get the label image out
%
% You can leave out h, then the current active figure is used.
%
% There are also some interactive changes that you can make:
%   t    toggles impaint on and off
%  Nc    selects another class label (prefix this command with the
%         class number N)
%  Nb    sets the brush size to N (prefix this command with the brush
%         size N)
%   s    save the current labels in Matlab variable 'lab'
%
% See also  im_update


% When nothing is defined:
if nargin<2
        varargin = {'on'};
end
% Special case, because an integer can be interpreted as a handle, we
% assume that when a single input is given, it is actually a label
if nargin==1
        if isnumeric(fig)
                varargin{1} = fig;
                fig = gcf;
        end
end
if nargin<1
        fig = gcf;
end
% make sure that the first input is the figure handle:
if ~ishandle(fig)
        varargin = {fig varargin{:}};
        fig = gcf;
end

% Check if we want to get/set the active class, or (re)define a class:
if isnumeric(varargin{1})
        allUD = get(fig,'userdata');
        if ~isfield(allUD,'impaint')
                error('This image does not have an overlay defined.');
        end
        UD=allUD.impaint; % our part of UD
        if length(varargin)==1  % we want to set/get the active class
                if varargin{1}>size(UD.msk_fg,1)
                        error('This class is not defined in the overlay.');
                else
                        UD.currlab = varargin{1};
                end
                % and (maybe more important) get the labels to the output
                if nargout>0
                        out = UD.labels;
                end
        else                    % we want to set the colours
                % We can process a whole list of colours...
                for i=1:2:(length(varargin)-1)
                        [nr,clr] = checkimpaintcolor(varargin{i},varargin{i+1});
                        UD.msk_fg(nr,:) = clr;
                        % Definition of the active label
                        UD.currlab = nr;
                end
        end
        % store everthing in the figure:
        set(fig,'UserData',[]);
        allUD.impaint=UD;
        set(fig,'UserData',allUD);
        return;
end


% Now check all the 'string' possibilities:
switch lower(varargin{1})
case 'on'

        % Set up variables:
        allUD=get(fig,'UserData'); % existing user data
        UD = [];   % Here I store the UserData

        % Put the image on screen
        UD.im_ax = findobj(get(fig,'children'),'type','axes');
        UD.im_im = findobj(get(UD.im_ax,'children'),'type','image');
        % get the size of the image
        sz = size(get(UD.im_im,'cdata'));

        %set(fig,'busyaction','cancel','DoubleBuffer','on');

        % Label storage:
        UD.labels = zeros(sz);  % background has label=0
        UD.labsize=size(UD.labels);
        
        % Mask image
        if length(sz)==2
                mskim = zeros([sz 3]);
        elseif length(sz)==3
                mskim = zeros(sz);
        else
                error('I cannot make a mask image for this image data.');
        end
        %mskim(1:50, 1:140, 1) = 1; % just to show something...
        % Definitions of the fore- and background colour
        if length(varargin)==3
                [nr,clr] = checkimpaintcolor(varargin{2},varargin{3});
                UD.msk_fg(nr,:) = clr;
                % Definition of the active label
                UD.currlab = nr;
        else
                UD.msk_fg = [1 0 0; 0 1 0; 0 0 1];   % standard: the first class is red.
                % Definition of the active label
                UD.currlab = 1;
        end
        UD.msk_bg = [0 0 0];
        % Definition of the brush-size
        UD.brushsz = 4;
        % define character command buffer:
        UD.charbuffer='';
        UD.state='on'; % impaint is toggled on

        % make a second axis for the overlay:
        UD.pos = get(UD.im_ax,'position');
        UD.msk_ax = axes('position', UD.pos);
        set(fig,'currentaxes',UD.msk_ax);
        UD.msk_im = imagesc(mskim);
        set(UD.msk_ax,'visible','off');
        msk2 = findobj(get(UD.msk_ax,'children'),'type','image');
        set(msk2,'alphadata',0.5);

        % set the window title:
        set(fig,'Name',sprintf('imprint on, brush: %d, class: %d',UD.brushsz,UD.currlab));
        
        % to speedup coordinate transformations later:
        UD.sz = sz;
        UD.W = sz(2)./UD.pos(3);
        UD.H = sz(1)./UD.pos(4);
        UD.pos(3) = UD.pos(3)+UD.pos(1);
        UD.pos(4) = UD.pos(4)+UD.pos(2);

        % now we have to define a callback
        oldh.btndown=get(fig,'WindowButtonDownFcn');
        set(fig,'WindowButtonDownFcn','im_update(''fill'')');
        oldh.btnup=get(fig,'WindowButtonUpFcn');
        set(fig,'WindowButtonUpFcn','im_update(''stopfill'')');
        oldh.keypress=get(fig,'KeyPressFcn');
        set(fig,'KeyPressFcn','im_update(''keypress'')');       

        % preserve previously set handlers
        UD.oldhandlers=oldh;
        
        % store everthing in the figure:
        set(fig,'UserData',[]);
        allUD.impaint=UD; % set our substructure in UD
        set(fig,'UserData',allUD);
        
        out=fig;
        return
        
case 'get'
        allUD = get(fig,'userdata');
        if ~isfield(allUD,'impaint')
                error('This image does not have an overlay defined.');
        end
        out = allUD.impaint.labels;
        
        return

case 'off'
        % Remove all the traces from the image:
        allUD = get(fig,'userdata');
        if ~isfield(allUD,'impaint')
                error('This image does not have an overlay defined.');
        end
        UD=allUD.impaint;
        delete(UD.msk_ax);

        % restore old handlers
        set(fig,'WindowButtonDownFcn',UD.oldhandlers.btndown);
        set(fig,'WindowButtonUpFcn',UD.oldhandlers.btnup);
        set(fig,'KeyPressFcn',UD.oldhandlers.keypress); 
        
        rmfield(allUD,'impaint');
        set(fig,'userdata',allUD);

        return

end

return

function [nr,clr] = checkimpaintcolor(nr,clr)
if ~isnumeric(nr)
        error('The class number should be a scalar.');
end
if (length(nr)~=1)
        error('The class number should be a scalar.');
end
if ~isnumeric(clr)
        error('The color definition should be 1x3 matrix.');
end
if (length(clr)~=3)
        error('The color definition should be 1x3 matrix.');
end
if any(clr<0)
        error('Colour values should be larger than 0.');
end
if any(clr>1)
        error('Colour values should be smaller than 1.');
end
% make it a nice row vector:
clr = clr(:)';
return