gtESF2LSF: fixed LSF computed against semitransparent edges

Signed-off-by: Nicola Vigano <nicola.vigano@esrf.fr>

zUtil_Imaging/gtESF2LSF.m

@@ -2,7 +2,7 @@ function lsf_line = gtESF2LSF(img, varargin)
     conf = struct( ...
         'bb', [], 'direction', [], ...
         'size', 21, 'oversampling', 5, 'data_type', 'single', ...
-        'side', 'both', 'use_astra', false, ...
+        'side', 'both', 'use_astra', false, 'exclude_border', 1, ...
         'keep_oversampling', true, 'verbose', true);
     conf = parse_pv_pairs(conf, varargin);
 
@@ -72,6 +72,8 @@ function lsf_line = gtESF2LSF(img, varargin)
 
     sum_esf = sum(rot_edge_img, 2)';
     lsf = diff(sum_esf);
+    border = conf.exclude_border * conf.oversampling;
+    lsf([1:border, end-border:end]) = 0;
     grad_pos = (1:numel(lsf)) + 0.5;
     [max_lsf_val, max_lsf_pos] = max(lsf);
     rel_max_lsf_pos = max_lsf_pos + 0.5;
@@ -104,7 +106,7 @@ function lsf_line = gtESF2LSF(img, varargin)
         lsf = reshape(lsf, conf.oversampling, conf.size);
         lsf = sum(lsf, 1);
     end
-    lsf = lsf / sum(lsf);
+    lsf = lsf / sum(abs(lsf));
 
     if (conf.verbose)
         f = figure();