twimshow(z, cmap, datasetNames, curImInd)

% twimshow - display and quickly switch between input images/ video sequences
% Version 2.0 
% Last update April 30, 2013 - Aram Danielyan

% usage examples 
% twimshow(video1)
%   or
% twimshow({video1 video2 ... videoN})
%   video1, video2, ..., videoN - are 2-D (images) or 3-D arrays

% twimshow({video1 video2 ... videoN}, [low high])
%   Display ALL sequences with [low high] intensity range. 
%   If [low high] is an empty matrix, dispaly range is set to
%   [min(video1(:)) max(video1(:))]

% twimshow({video1 video2 ... videoN}, {[low1 high1] [low2 high2] ... [lowN highN]})
%   Display squence K with the intensity range [lowK highK]. 
%   If [lowK highK] is an empty matrix, the dispaly range for K-th sequence is set to
%   [min(videoK(:)) max(videoK(:))]

% twimshow({video1 video2 ... videoN}, {[low1 high1] [low2 high2] ... [lowN highN]})
%   Display squence K with the intensity range [lowK highK]. 
%   If [lowK highK] is an empty matrix, the dispaly range for K-th sequence is set to
%   [min(videoK(:)) max(videoK(:))]

% twimshow({video1 video2 ... videoN}, {[low1 high1] [low2 high2] ... [lowN highN]}, ...
%               {'name1', 'name2', ...., 'nameN'})
% 	Show nameK as a captions when videoK is displayed

% key controls
% 1,2,3, ..., 9, 0 - switch between inputs
% left/right arrow keys - show next/previous frame 
% c - change brightness/contrast via imcontrast

function twimshow(z, cmap, datasetNames, curImInd)
    link_cmaps = false;
    
    if ~iscell(z), z={z}; end
    
    if ~exist('cmap','var') || isempty(cmap)
         cmap{1}= [];
    elseif ~iscell(cmap)
        cmap= {cmap};
    end
    
    if (numel(cmap)==1), link_cmaps = true; end
    
    for m=1:numel(cmap)
        if isempty(cmap{m})
            cmap{m} = [min(z{m}(:)) max(z{m}(:))];
        end
    end
    
    if ~exist('datasetNames','var'), datasetNames=[]; end;
    % fill in missing names with dataset indecies
    for k=(numel(datasetNames)+1):numel(z); 
        datasetNames{k} = num2str(k);
    end
        
    if ~exist('curImInd','var'), curImInd = 1; end
    prevImInd = 1;
    hImage = [];
    hTitle = [];
    curFrameInd =1;
    SetCurrentImage(curImInd);

    set(gcf, 'WindowKeyPressFcn',@KeyPress_proc);
    
    function KeyPress_proc(src,evnt)
        switch evnt.Key 
            case{'t'}
                SetCurrentImage(curImInd+1);
            case{'rightarrow'}
                SetCurrentFrame(curFrameInd+1);
            case{'leftarrow'}
                SetCurrentFrame(curFrameInd-1);
            case{'c'}
                imcontrast
            case{'r'}
                impixelregion   
            case{'1','2','3','4','5','6','7','8','9','0'}
                ind=str2double(evnt.Character);
                if ind==0, ind=10; end
                if ind <= numel(z), SetCurrentImage(ind); end
        end
    end
    function SetCurrentImage(imIndex)
        if imIndex > numel(z), imIndex =1; end
        
        prevImInd = curImInd;    
        curImInd = imIndex;
        
        if ~link_cmaps && ~isempty(hImage)
            cmap{prevImInd} = get(gca,'CLim');
            set(gca,'CLim',cmap{curImInd});  
        end
        
        displayimage
    end
    function SetCurrentFrame(frameInd)
        if frameInd > size(z{curImInd},3) 
            frameInd = 1; 
        elseif frameInd < 1
            frameInd = size(z{curImInd},3); 
        end
        curFrameInd = frameInd;
        displayimage
    end
    function displayimage
        titleString = sprintf('%s Frame:%d', datasetNames{curImInd},curFrameInd);
        if isempty(hImage)
            figure;
            hImage = imshow(z{curImInd}(:,:,curFrameInd), cmap{curImInd});
            hTitle = title(gca, titleString);
            return;
        end
        
        set(hImage, 'CData',z{curImInd}(:,:,curFrameInd));
        set(hTitle,'String', titleString);
    end 
end