% centerSurroundTopDown - pseudo center-surround for top-down maps.%% [featureMaps,csLevels] = centerSurroundTopDown(pyramid,salParams)%    Only resizes and border-attenuates the level maps of the pyramid.%    This version does NOT compute center-surround differences.%    It is meant for top-down attention maps fed in from an outside%    source, e.g. object-sensitive maps. This version was used in:%      Dirk B. Walther & Christof Koch (2007). Attention in %      Hierarchical Models of Object Recognition. In P. Cisek, %      T. Drew & J. F. Kalaska (Eds.), Progress in Brain Research: %      Computational Neuroscience: Theoretical insights into brain %      function. Amsterdam: Elsevier.%%    featureMaps is a vector of maps with the results.%    csLevels returns the center and surround levels in%       pyramid for later reference.%% See also centerSurround, defaultSaliencyParams, makeSaliencyMap,%          dataStructures.% This file is part of the SaliencyToolbox - Copyright (C) 2006-2007% by Dirk B. Walther and the California Institute of Technology.% See the enclosed LICENSE.TXT document for the license agreement. % More information about this project is available at: % http://www.saliencytoolbox.netfunction [featureMaps,csLevels] = centerSurroundTopDown(pyr,salParams)switch salParams.pyramidType  case 'sqrt2'    base = sqrt(0.5);  case 'dyadic'    base = 0.5;  otherwise    fatal(['Unknown pyramidType: ' salParams.pyramidType]);endsiz = floor(pyr.origImage.size(1:2) * base^(salParams.levelParams.mapLevel-1));borderSize = round(max(siz)/20);for i = 1:length(pyr.levels)  featureMaps(i) = pyr.levels(i);  tmp = imresize(pyr.levels(i).data,siz,'nearest');  featureMaps(i).data = attenuateBorders(tmp,borderSize);  featureMaps(i).date = timeString;  featureMaps(i).parameters = salParams;  csLevels(i).centerLevel = i;  csLevels(i).surroundLevel = i;end