在Matlab中应用一组图像滤波器

function FiltIm = ApplyFilterBank(im,filters)
%#function FiltIm = ApplyFilterBank(im,filters)
%#
%#assume im is a single layer image, and filters is a cell array

nFilt = length(filters);
maxsz = 0;
for i = 1:nFilt
  maxsz = max(maxsz,max(size(filters{i})));
end
FiltIm = zeros(size(im,1), size(im,2), nFilt);
im = padimage(im,maxsz,\'symmetric\');
for i = 1:nFilt
  FiltIm(:,:,i) = unpadimage(imfilter(im,filters{i}),maxsz);
end

function o = padimage(i,amnt,method)
%#function o = padimage(i,amnt,method)
%#
%#padarray which operates on only the first 2 dimensions of a 3 dimensional
%#image. (of arbitrary number of layers);
%#
%#String values for METHOD
%#        \'circular\'    Pads with circular repetion of elements.
%#        \'replicate\'   Repeats border elements of A.
%#        \'symmetric\'   Pads array with mirror reflections of itself. 
%#
%#if(amnt) is length 1, then pad all sides same amount
%#
%#if(amnt) is length 2, then pad y direction amnt(1), and x direction amnt(2)
%#
%#if(amnt) is length 4, then pad sides unequally with order LTRB, left top right bottom
if(nargin < 3)
   method = \'replicate\';
end
if(length(amnt) == 1)
  o = zeros(size(i,1) + 2 * amnt, size(i,2) + 2* amnt, size(i,3));
  for n = 1:size(i,3)
    o(:,:,n) = padarray(i(:,:,n),[amnt,amnt],method,\'both\');
  end
end
if(length(amnt) == 2)
  o = zeros(size(i,1) + 2 * amnt(1), size(i,2) + 2* amnt(2), size(i,3));
  for n = 1:size(i,3)
    o(:,:,n) = padarray(i(:,:,n),amnt,method,\'both\');
  end
end
if(length(amnt) == 4)
  o = zeros(size(i,1) + amnt(2) + amnt(4), size(i,2) + amnt(1) + amnt(3), size(i,3));
  for n = 1:size(i,3)
    o(:,:,n) = padarray(padarray(i(:,:,n),[amnt(2), amnt(1)],method,\'pre\'),[amnt(4),     amnt(3)],method,\'post\');
  end
end

function o = unpadimage(i,amnt)
%#un does padimage
%#if length(amnt == 1), unpad equal on each side
%#if length(amnt == 2), first amnt is left right, second up down
%#if length(amnt == 4), then [left top right bottom];

switch(length(amnt))
case 1
  sx = size(i,2) - 2 * amnt;
  sy = size(i,1) - 2 * amnt;
  l = amnt + 1;
  r = size(i,2) - amnt;
  t = amnt + 1;
  b = size(i,1) - amnt;
case 2
  sx = size(i,2) - 2 * amnt(1);
  sy = size(i,1) - 2 * amnt(2);
  l = amnt(1) + 1;
  r = size(i,2) - amnt(1);
  t = amnt(2) + 1;
  b = size(i,1) - amnt(2);
case 4
  sx = size(i,2) - (amnt(1) + amnt(3));
  sy = size(i,1) - (amnt(2) + amnt(4));
  l = amnt(1) + 1;
  r = size(i,2) - amnt(3);
  t = amnt(2) + 1;
  b = size(i,1) - amnt(4);
otherwise
  error(\'illegal unpad amount\\n\');
end
if(any([sx,sy] < 1))
    fprintf(\'unpadimage newsize < 0, returning []\\n\');
    o = [];
    return;
end

o = zeros(sy, sx, size(i,3));
for n = 1:size(i,3)
  o(:,:,n) = i(t:b,l:r,n);
end