function resizephotos(directory, wh, isrecursive, isoverwrite, savetopath, supportFormat)

% resizephotos: resize a batch of photos

%

% resizephotos -dir max_width_and_height, will let you choose a directory,

% and resize all the photos in the directory. When max_width_and_height is

% omitted, it uses 1600 by default(1600px is enough for most monitors).

%

% resizephotos -files max_width_and_height, will let you choose some files,

% and resize all the files in the directory.

%

% You might be asked for whether to recursively resize all the photos in

% subdirectories.

%

% and You might be asked for whether to overwrite the original files. If

% you choose 'No', the program will save the resized images in new

% directories or files with prefix 'resize-'.

%

% resizephotos(file_or_directory, max_width_and_height, is_recursive, ...

% is_overwrite, path_to_save): you can use the function by specifying

% the path of the directories and files. When using this method, you can

% specific the max width and height of the resized photos. When path_to_save

% is omitted, the path to save the resized photos will generated automatically

% depends on is_overwrite parameter.

%

%

% See also imresize

%

% Copyright 2010, zhiqiang.org

% author: zhang@zhiqiang.org, url:

% http://zhiqiang.org/blog/it/batch-resize-images-using-matlab.html

%   $Revision: 1.1.6.28.2.1 $  $Date: 2009/01/27 04:47:43 $

%% cope with the input parameters

% if the directory is not set, we open a file select dialog for use to

% select the files or path to deal with

if nargin == 0 || (nargin >= 1 && ischar(directory) && strcmp(directory, '-dir'))

    directory = uigetdir;

    % let user to choose whether recursively resize all the subdirectories

    tmp = questdlg('Did you want to recursively resize all the subdirectories?');

    if strcmp('Yes', tmp)

        isrecursive = true;

    else strcmp('No', tmp)

        isrecursive = false;

    end

    isoverwrite = askforoverwrite();

elseif (nargin >= 1 && ischar(directory) && strcmp(directory, '-files'))

    [p, f] = uigetfile({'*.*', 'All files'}, 'MultiSelect', 'on');

    if isnumeric(p) && ~p

        return;

    end

    directory = cell(size(p));

    if iscell(p)

        for i = 1:numel(p)

            directory{i} = [f, p{i}];

        end

    else

        directory=[f p];

    end

    isoverwrite = askforoverwrite();

end

% set other parameters

if ~exist('wh', 'var'), wh = 1600; elseif ischar(wh), wh = eval_r(wh); end %����eval����_r

if ~exist('isrecursive', 'var'), isrecursive = false; end

if ~exist('isoverwrite', 'var'), isoverwrite = false; end

if ~exist('savetopath', 'var'), savetopath = []; end

if nargin <= 5 || isempty(supportFormat), supportFormat = '*'; end

%% mult-files

% if directory is a cell, it indicate multi-files or multi-directories,

% we resize them one by one

if iscell(directory)

    for i = 1:numel(directory)

        resizephotos(directory{i}, wh, isrecursive, isoverwrite, savetopath, supportFormat);

    end

    return;

end

%% if everything are OK

if exist(directory, 'file') &&  ~isdir(directory) % for a file,

    if nargin <= 4 || isempty(savetopath)

        if isoverwrite

            savetopath = directory;

        else

            [pd, fd] = lastdirectory(directory);

            savetopath = [pd, 'resize-', fd];

        end

    end

    resizesinglephoto(directory, wh, savetopath);

elseif isdir(directory) % if directory is a real directory

    % the last char of directory should be a '\'

    if directory(end) ~= '\'

        directory = [directory, '\'];

    end

    % generate the saved directory

    if nargin <= 4 || isempty(savetopath) % when at the first recursive and savetopath is not set

        % we need to generate the saved directory

        if isoverwrite

            savetopath = directory;

        elseif ~isoverwrite

            [savetopath, lastd] = lastdirectory(directory);

            savetopath = [savetopath, 'resize-', lastd, '\'];

        end

        % when the savetopath do not exist, we create one

        if ~isdir(savetopath)

            mkdir(savetopath);  %����������������

        end

    end

    % now we resize all photos in current directory, and recursive resize

    % all the directories if needed

    allfiles = dir(directory);  %����������������(������������)������������������

    % before we generate now image file, we first make sure the savetopath

    % exists, otherwise generate it.

    if ~isdir(savetopath)

        savetopath=[savetopath(1:end-1) 'resize' '\'];

        mkdir(savetopath);  %��������������������������������resize

    end

    for i = 1:numel(allfiles)

        cur = allfiles(i).name;

        % ignore the path '.' and '..'

        if numel(cur) > 2 || ~min(cur == '.')

            if allfiles(i).isdir && isrecursive

                resizephotos([directory cur '\'], wh, isrecursive, isoverwrite, ...

                    [savetopath cur '\'], supportFormat);

            elseif ~allfiles(i).isdir

                resizesinglephoto([directory cur], wh, [savetopath cur]);

            end

        end

    end

end

%% resize single photo, save it to savetopath

function resizesinglephoto(photo, wh, savetopath)

try

    I = imread(photo);

catch ME %#ok<NASGU>

    % disp(ME.message);

    disp(['!!! ' photo ' is not recognized as an image file, and it''s ignored']);

    return;

end

% [w, h] is the width and height of original graph

w = size(I, 1);

h = size(I, 2);

% ����resize�������� [maxw, maxh]

if numel(wh) == 1

    if w > h

        maxw = wh;

        maxh = wh*h/w;

    else

        maxh = wh;

        maxw = wh*w/h;

    end

else

    maxw = wh(1);

    maxh = wh(2);

    if (w-h)*(maxw-maxh) < 0

        [maxw, maxh] = deal(h, w);

    end

    if w/h < maxw/maxh

        maxw = maxh*w/h;

    else

        maxh = maxw*h/w;

    end

end

if maxw < w

    I = imresize(I, [maxw, maxh]);   %����������������������������������������������������

end

imwrite(I, savetopath);

disp([photo ' is resized, and is saved to ' savetopath]);

%% lastdirectory

function [pd, ld] = lastdirectory(d)

% return the last directory, for example, lastdirectory('\abc\edf\') =

% ['\abc\','edf']. When d is a file, return the path and the file name, i.e

% lastdirectory('abc\def\x.jpg') = ['abc\def\', 'x.jpg']

% remove the last \

if isdir(d) && d(end) == '\'

    d = d(1:end-1);

end

% if there is a \

if max(d=='\')

    ld = d(find(d=='\', 1, 'last')+1:end);

else

    ld = d;

end

pd = d(1:end-numel(ld));

%% ask for whether to overwrite original files

function isoverwrite = askforoverwrite()

tmp = questdlg(['Did you want to overwrite the original files? ' ...

        'if you choose No, we will add a ''resize-'' prefix to your ' ...

        'files or directories.']);

if strcmp('Yes', tmp)

    isoverwrite = true;

elseif strcmp('No', tmp)

    isoverwrite = false;

end