comparison Problems/Pierre_Problem.m @ 10:207a6ae9a76f version1.0

(none)

+function data=Pierre_Problem(src, trg, blocksize, dictsize);
+%%% Generate Pierre Problem
+%   Ivan Damnjanovic 2010 
+%
+%   Pierre_Problem is a part of the SMALLbox and generates the problem
+%   suggested by Professor Pierre Vandergheynst on the SMALL meeting in 
+%   Villars.
+%   The function takes as an input:
+%   -   src - source image matrix (if not present function promts user for 
+%             an image file) ,
+%   -   trg - target image matrix (if not present function promts user for 
+%             an image file) ,
+%   -   blocksize - block (patch) vertical/horizontal dimension (default 8),
+%   -   dictsize - dictionary size (default - all patches from target
+%   image).
+%
+%   The output of the function is stucture with following fields:
+%   -   srcname - source image name,
+%   -   imageSrc - source image matrix,
+%   -   trgname - target image name,
+%   -   imageTrg - Target image matrix,
+%   -   A - dictonary with patches from the source image,
+%   -   b - measurement matrix (i.e. patches from target image to be
+%           represented in dictionary A,
+%   -   m - size of patches (default 25),
+%   -   n - number of patches to be represented,
+%   -   p - dictionary size,
+%   -   blocksize - block size (default [5 5]),
+%   -   maxval - maximum value (default - 255)
+%   -   sparse - if 1 SMALL_solve will keep solution matrix in sparse form,
+%                due to memory constrains.
+
+%% prompt user for images %%
+
+%ask for source file name
+
+TMPpath=pwd;
+FS=filesep;
+if ~ exist( 'src', 'var' ) || isempty(src)
+[pathstr1, name, ext, versn] = fileparts(which('SMALLboxSetup.m'));
+cd([pathstr1,FS,'data',FS,'images']);
+[filename,pathname] = uigetfile({'*.png;'},'Select a source image');
+[pathstr, name, ext, versn] = fileparts(filename);
+data.srcname=name;
+src = imread(filename);
+src = double(src);
+end;
+
+%ask for target file name
+
+if ~ exist( 'trg', 'var' ) || isempty(trg)
+[filename,pathname] = uigetfile({'*.png;'},'Select a target image');
+[pathstr, name, ext, versn] = fileparts(filename);
+data.trgname=name;
+trg = imread(filename);
+trg = double(trg);
+end;
+cd(TMPpath);
+
+%% set parameters %%
+
+maxval = 255;
+if ~ exist( 'blocksize', 'var' ) || isempty(blocksize),blocksize = 5;end
+
+if ~ exist( 'dictsize', 'var' ) || isempty(dictsize),
+    dictsize = (size(src,1)-blocksize+1)*(size(src,2)-blocksize+1);
+    patch_idx=1:dictsize;
+else  
+    num_blocks_src=(size(src,1)-blocksize+1)*(size(src,2)-blocksize+1);
+    patch_idx=1:floor(num_blocks_src/dictsize):dictsize*floor(num_blocks_src/dictsize);
+end
+
+p = ndims(src);
+if (p==2 && any(size(src)==1) && length(blocksize)==1)
+  p = 1;
+end
+
+
+% blocksize %
+if (numel(blocksize)==1)
+  blocksize = ones(1,p)*blocksize;
+end
+%%
+%% create dictionary data %%
+
+S=im2col(src,blocksize,'sliding');
+
+for j= 1:size(S,2)
+    S(:,j)=S(:,j)./norm(S(:,j));
+end
+
+%% create measurement matrix %%
+
+T=im2col(trg,blocksize, 'distinct');
+
+%% output structure %%
+
+data.imageSrc = src;
+data.imageTrg = trg;
+data.A = S(:,patch_idx);
+data.b = T;
+data.m = size(T,1);
+data.n = size(T,2);
+data.p = size(data.A,2);
+data.blocksize=blocksize;
+data.maxval=maxval;
+
+% geting around out of memory problem when converting big matrix from
+% sparse to full... (check SMALL_solve function)
+data.sparse=1;
+
+