idamnjanovic@52: function P = thumbFromOp(op,m,n,sm,sn,grayscale)
idamnjanovic@52: % Output matrix P, of size m x n, sampled at
idamnjanovic@52: % sm x sn upper top
idamnjanovic@52: 
idamnjanovic@52: %   Copyright 2008, Ewout van den Berg and Michael P. Friedlander
idamnjanovic@52: %   http://www.cs.ubc.ca/labs/scl/sparco
idamnjanovic@52: %   $Id: thumbFromOp.m 1040 2008-06-26 20:29:02Z ewout78 $
idamnjanovic@52: 
idamnjanovic@52: if nargin < 6, grayscale = 0; end
idamnjanovic@52:     
idamnjanovic@52: info = op([],0);
idamnjanovic@52: 
idamnjanovic@52: sm = min(info{1},sm);
idamnjanovic@52: sn = min(info{2},sn);
idamnjanovic@52: M  = zeros(sm,sn);
idamnjanovic@52: 
idamnjanovic@52: for i=1:sn
idamnjanovic@52:    v = zeros(info{2},1); v(i) = 1;
idamnjanovic@52:    w = real(op(v,1));
idamnjanovic@52: 
idamnjanovic@52:    M(:,i) = w(1:sm);
idamnjanovic@52: end
idamnjanovic@52: 
idamnjanovic@52: mn = min(min(M));
idamnjanovic@52: mx = max(max(M));
idamnjanovic@52: M  = (M - mn) / (mx-mn);
idamnjanovic@52: 
idamnjanovic@52: idxm = floor(linspace(1,sm+1,m+1)); idxm = idxm(1:end-1);
idamnjanovic@52: idxn = floor(linspace(1,sn+1,n+1)); idxn = idxn(1:end-1);
idamnjanovic@52: 
idamnjanovic@52: if grayscale
idamnjanovic@52:    P = 1-M(idxm,idxn);
idamnjanovic@52: else
idamnjanovic@52:    clrmap = hsv;
idamnjanovic@52:    M = 1 + round(M * (length(clrmap)-1));
idamnjanovic@52:    P = zeros(m,n,3);
idamnjanovic@52:    for j1=1:m
idamnjanovic@52:        for j2=1:n
idamnjanovic@52:            P(j1,j2,:) = clrmap(M(idxm(j1),idxn(j2)),:);
idamnjanovic@52:        end
idamnjanovic@52:    end
idamnjanovic@52: end