ivan@130: function data=generatePierre_Problem(src, trg, blocksize, dictsize);
ivan@130: %%  Generate Pierre Villars Problem
ivan@130: %
ivan@130: %   Pierre_Problem is a part of the SMALLbox and generates the problem
ivan@130: %   suggested by Professor Pierre Vandergheynst on the SMALL meeting in 
ivan@130: %   Villars.
ivan@130: %   The function takes as an input:
ivan@130: %   -   src - source image matrix (if not present function promts user for 
ivan@130: %             an image file) ,
ivan@130: %   -   trg - target image matrix (if not present function promts user for 
ivan@130: %             an image file) ,
ivan@130: %   -   blocksize - block (patch) vertical/horizontal dimension (default 8),
ivan@130: %   -   dictsize - dictionary size (default - all patches from target
ivan@130: %   image).
ivan@130: %
ivan@130: %   The output of the function is stucture with following fields:
ivan@130: %   -   srcname - source image name,
ivan@130: %   -   imageSrc - source image matrix,
ivan@130: %   -   trgname - target image name,
ivan@130: %   -   imageTrg - Target image matrix,
ivan@130: %   -   A - dictonary with patches from the source image,
ivan@130: %   -   b - measurement matrix (i.e. patches from target image to be
ivan@130: %           represented in dictionary A,
ivan@130: %   -   m - size of patches (default 25),
ivan@130: %   -   n - number of patches to be represented,
ivan@130: %   -   p - dictionary size,
ivan@130: %   -   blocksize - block size (default [5 5]),
ivan@130: %   -   maxval - maximum value (default - 255)
ivan@130: %   -   sparse - if 1 SMALL_solve will keep solution matrix in sparse form,
ivan@130: %                due to memory constrains.
ivan@130: 
ivan@130: %
ivan@130: %   Centre for Digital Music, Queen Mary, University of London.
ivan@130: %   This file copyright 2010 Ivan Damnjanovic.
ivan@130: %
ivan@130: %   This program is free software; you can redistribute it and/or
ivan@130: %   modify it under the terms of the GNU General Public License as
ivan@130: %   published by the Free Software Foundation; either version 2 of the
ivan@130: %   License, or (at your option) any later version.  See the file
ivan@130: %   COPYING included with this distribution for more information.
ivan@130: %% prompt user for images %%
ivan@130: 
ivan@130: %   ask for source file name
ivan@130: 
ivan@130: TMPpath=pwd;
ivan@130: FS=filesep;
ivan@130: if ~ exist( 'src', 'var' ) || isempty(src)
luis@186: [pathstr1, name, ext] = fileparts(which('SMALLboxSetup.m'));
ivan@130: cd([pathstr1,FS,'data',FS,'images']);
ivan@130: [filename,pathname] = uigetfile({'*.png;'},'Select a source image');
luis@186: [pathstr, name, ext] = fileparts(filename);
ivan@130: data.srcname=name;
ivan@130: src = imread(filename);
ivan@130: src = double(src);
ivan@130: end;
ivan@130: 
ivan@130: %   ask for target file name
ivan@130: 
ivan@130: if ~ exist( 'trg', 'var' ) || isempty(trg)
ivan@130: [filename,pathname] = uigetfile({'*.png;'},'Select a target image');
luis@186: [pathstr, name, ext] = fileparts(filename);
ivan@130: data.trgname=name;
ivan@130: trg = imread(filename);
ivan@130: trg = double(trg);
ivan@130: end;
ivan@130: cd(TMPpath);
ivan@130: 
ivan@130: %% set parameters %%
ivan@130: 
ivan@130: maxval = 255;
ivan@130: if ~ exist( 'blocksize', 'var' ) || isempty(blocksize),blocksize = 5;end
ivan@130: 
ivan@130: if ~ exist( 'dictsize', 'var' ) || isempty(dictsize),
ivan@130:     dictsize = (size(src,1)-blocksize+1)*(size(src,2)-blocksize+1);
ivan@130:     patch_idx=1:dictsize;
ivan@130: else  
ivan@130:     num_blocks_src=(size(src,1)-blocksize+1)*(size(src,2)-blocksize+1);
ivan@130:     patch_idx=1:floor(num_blocks_src/dictsize):dictsize*floor(num_blocks_src/dictsize);
ivan@130: end
ivan@130: 
ivan@130: p = ndims(src);
ivan@130: if (p==2 && any(size(src)==1) && length(blocksize)==1)
ivan@130:   p = 1;
ivan@130: end
ivan@130: 
ivan@130: 
ivan@130: % blocksize %
ivan@130: if (numel(blocksize)==1)
ivan@130:   blocksize = ones(1,p)*blocksize;
ivan@130: end
ivan@130: %%
ivan@130: %% create dictionary data %%
ivan@130: 
ivan@130: S=im2colstep(src,blocksize);
ivan@130: 
ivan@130: for j= 1:size(S,2)
ivan@130:     S(:,j)=S(:,j)./norm(S(:,j));
ivan@130: end
ivan@130: 
ivan@130: %% create measurement matrix %%
ivan@130: 
ivan@130: T=im2colstep(trg,blocksize, blocksize);
ivan@130: 
ivan@130: %% output structure %%
ivan@130: 
ivan@130: data.imageSrc = src;
ivan@130: data.imageTrg = trg;
ivan@130: data.A = S(:,patch_idx);
ivan@130: data.b = T;
ivan@130: data.m = size(T,1);
ivan@130: data.n = size(T,2);
ivan@130: data.p = size(data.A,2);
ivan@130: data.blocksize=blocksize;
ivan@130: data.maxval=maxval;
ivan@130: 
ivan@130: %   keep coefficients matrix in sparse form and do not convert it to full.
ivan@130: %   getting around out of memory problem when converting big matrix from
ivan@130: %   sparse to full... (check SMALL_solve function)
ivan@130: data.sparse=1;
ivan@130: 
ivan@130: