example on how to save hpatches descriptors for hbench

ex.lua

require 'cutorch'
require 'xlua'
require 'trepl'
require 'cunn'
require 'cudnn'
require 'image'
require 'nn'
require 'torch'
require 'lfs'

-- hard-coded patch-image extention
ext = '.png'

-- descr name
descr_name = arg[1]
-- patch size for this descr
patch_size = arg[2]
-- folder with sequence-patches to describe (root folder)
patches_folder = arg[3]

-- load the description network
local net = torch.load('nets/'..descr_name..'.t7'):cuda()
stats = torch.load('nets/stats.liberty.t7')

-- make the dir with the results
lfs.mkdir(descr_name)

-- loop through the sequences
for seq in lfs.dir(patches_folder) do
   if seq ~= "." and seq ~= ".." and seq ~= "test_set.txt" then
      print("Computing descriptors for sequence: "..seq)
      lfs.mkdir(descr_name.."/"..seq)
      for file in paths.files(patches_folder..seq) do
	 if file:find(ext .. '$') then
	    -- hpatches image, compute the descriptors
	    local img = image.load(patches_folder..seq.."/"..file,1)
	    img:add(-stats.mi):div(stats.sigma)
	    -- split the patches-image to patches
	    patches = img:split(65,2)
	    for i,p in ipairs(patches) do 
	       patches[i] = image.scale(p,patch_size,patch_size)
	    end
	    -- fix the input for the CNN
	    patches = torch.cat(patches,1)
	    N = patches:size(1)
	    patches = patches:view(N,1,patch_size,patch_size):cuda()
	    descrs = net:forward(patches)
	    -- save the output descriptors in csv file
	    file = io.open (descr_name.."/"..seq.."/"..string.gsub(file,'.png','')..".csv","w")
	    for i=1,descrs:size(1) do 
	       for j=1,descrs:size(2) do 
		  file:write(descrs[i][j])
		  if (j<descrs:size(2)) then
		     file:write(",")
		  end
	       end
	       file:write("\n")
	    end
	    file:close()
	 end
      end
   end
end