grayish - gray out the lower end of a spectrum for less severe palette function cmap = grayish(cmap,minval); assumes standard two-dimensional color map of three columns
0001 function cmap = grayish(cmap,minval); 0002 0003 % grayish - gray out the lower end of a spectrum for less severe palette 0004 % function cmap = grayish(cmap,minval); 0005 % assumes standard two-dimensional color map of three columns 0006 0007 % $Revision: 1.1 $ $Date: 2004/11/12 01:32:35 $ 0008 0009 0010 [m,n] = size(cmap); 0011 0012 if(length(minval) == 1), 0013 minval = minval + zeros(1,3); 0014 end 0015 0016 for i = 1:3, 0017 cmap(:,i) = max(cmap(:,i),minval(i)); % set threshold 0018 end 0019 0020 startndx = 0; % looking for highest index 0021 for i = 1:3, 0022 startndx = max(startndx,min(find(cmap(:,1) > minval(i)))); 0023 end 0024 0025 % so color above this are above the minval 0026 0027 cmap = cmap(startndx:end,:); % only those values 0028 0029 % now rescale to full range by interpolating 0030 mtrunc = size(cmap,1); % new length 0031 ndx = [0:(mtrunc-1)]/(mtrunc-1)*(m-1); % scales to new range 0032 0033 cmap = interp1(ndx,cmap,[0:(m-1)]); 0034 0035 return